Is the GAT / ET5 hard on tubes?

[turntable]

I have had my GAT for several months and I am on my third set of factory 6922 tubes

The tubes do not fail, but get noisy with tube hiss. I noticed the right channel had got noisy. Lucky I have a set of ten left from my art, however this is not good.

I can't see how you can blame the eh tubes as I have not had these issues with my art/prem 16 in the past.

Anyone else had any tube noise issues?

[Rafale]

Shane.....I have never had problems with 6922 sovtek / EH on my GAT
I have at present Mullard Holland NOS and I wait for EAT ECC88... no problem of noise
You should speak about it to Ed

[turntable]

Philippe

I have friend in the UK that has had similar problems, however not recently with expensive aperex tubes

The GAT still plays music fine, but the increased tube rush is irritating

[Rafale]

Philippe

I have friend in the UK that has had similar problems, however not recently with expensive aperex tubes

The GAT still plays music fine, but the increased tube rush is irritating

strange :scratch2 :I will inform you regarding the EAT, they arrive next week

[Rayooo]

I've had three tube failures in last couple years, two in ET-3 SE.
One of the failures was the stock CJ tube (Noisy) 2nd in ET-3SE was a Mullard I believe from Tube Depot.

3rd was earlier this year, EAT in ET-5.

In each case, the tube was good one minute and failed during use, went immediately noisy and/or very microphonic. My "assumption" is that each was simply a failure and not affected by the specific use by CJ.. but I surely don't know that for a fact.

...and I don't play heavy-metal music. :)

[PHC1]

Shane, have you tried Genalex Gold Lion 6922? It is supposed to be the best quality. New Sensor::Product HighLight (http://www.newsensor.com/ProductHighLight.aspx?ProId=1347)

[Puma Cat]

Anyone else had any tube noise issues?

Nope.

[Joe Appierto]

I have had my GAT for several months and I am on my third set of factory 6922 tubes

Anyone else had any tube noise issues?

Shane,

I had a set of Amperex 6922s become microphonic in about 200-250 hours use in a Pr 17 LS but that was it. Never had the problem at all in my 16 LS2 but for one reason or another I now typically use 6DJ8s, 7DJ8s and 7308s not 6922s. And never had tubes becomes noisy although I've replaced some that were just getting to the end of their time and becoming kind of dull sounding.

Regards,
Joe

[turntable]

Shane, have you tried Genalex Gold Lion 6922? It is supposed to be the best quality. New Sensor::Product HighLight (http://www.newsensor.com/ProductHighLight.aspx?ProId=1347)

Serge, Gotta get past my 1000 hours teflon burnin playtime before I start experimenting on different tubes - especially expensive ones. :yes:

That will be on this list as with only two required, not that big an outlay.

[turntable]

Shane,

I had a set of Amperex 6922s become microphonic in about 200-250 hours use in a Pr 17 LS but that was it. Never had the problem at all in my 16 LS2 but for one reason or another I now typically use 6DJ8s, 7DJ8s and 7308s not 6922s. And never had tubes becomes noisy although I've replaced some that were just getting to the end of their time and becoming kind of dull sounding.

Regards,
Joe

Hi Joe, great to see you join us cj fans here. :thumbsup:

maybe I am being fussy? the tubes are not microphonic or anything. the tube rush comiong out of the tweeter is louder that it should be, and louder on one channel than the other. I put in another cj EH 6922 and the noise reduces back to normal.

Not something you can even hear from the listening chair unless you are looking for it.

But in the new year, it will be time to try a few alternatives and have some fun.

[Puma Cat]

I'm still doin' pretty good with the stock EH 6922s in my Premier 17. I don't know if they've ever been replaced as I'm the second owner of this fine pre. I do want to get some GL 6922s in to try those out, or maybe some Ediswans.

The CT-5 hasn't been a problem, but I think I'm just now getting somewhere around the 1000 hr mark, and those 6H30/6N30s were specifically designed to be extremely durable, so no issues there.

[ronenash]

I have had my GAT for several months and I am on my third set of factory 6922 tubes

The tubes do not fail, but get noisy with tube hiss. I noticed the right channel had got noisy. Lucky I have a set of ten left from my art, however this is not good.

I can't see how you can blame the eh tubes as I have not had these issues with my art/prem 16 in the past.

Anyone else had any tube noise issues?

I have confirmed with CJ that there was a defective series of tube from EH. It appears the 2010 series of 6922 have had a high failure rate with many going noisy only after a few hundred hours.
I have seen this in the ET3 as well as the ET5. In both cases putting in another tube (either JJ 6922 or even better Gold Lion 6922) took care of the problem.
As a general rule, avoid EH 6922 that have the 2010 date on them.

Tubes is the ET5 should last 3-5 year without a problem.

[Myles B. Astor]

I have confirmed with CJ that there was a defective series of tube from EH. It appears the 2010 series of 6922 have had a high failure rate with many going noisy only after a few hundred hours.
I have seen this in the ET3 as well as the ET5. In both cases putting in another tube (either JJ 6922 or even better Gold Lion 6922) took care of the problem.
As a general rule, avoid EH 6922 that have the 2010 date on them.

Tubes is the ET5 should last 3-5 year without a problem.

Great, that's when I bought a backup pair :(

[turntable]

I have confirmed with CJ that there was a defective series of tube from EH. It appears the 2010 series of 6922 have had a high failure rate with many going noisy only after a few hundred hours.
I have seen this in the ET3 as well as the ET5. In both cases putting in another tube (either JJ 6922 or even better Gold Lion 6922) took care of the problem.
As a general rule, avoid EH 6922 that have the 2010 date on them.

Tubes is the ET5 should last 3-5 year without a problem.

Most of my spare ones 411are 07 09. Replacement gat two are 09 09

[ronenash]

I am sure EH had qality issues in other series tubes as well. Try a Gold Lion and you should have no problems for years to come. Although its the same company the quality control on the GL's is much better.

[Rayooo]

I don't know if it's my bad luck with tubes, the ET-5 being somewhat tough on tubes or what. :tears:

In the last few days... the system has been moving to sounding "2D" vs that lush magical almost "3D" sound stage. bass seemed a bit anemic and overall just less pleasing.

Just for the heck of it on a whim today, I popped the Ediswan 6922 back in. well right off the deep end was back..and I was back to "seeing the sound in 3D"

So then I do my standard micro phonics tube test on the Ediswan. A simple light touch of the tube in question. In this case it causes a monstrous sound in both speakers. This tube has become one of the best microphones I've ever seen. I know some of this is normal with any tube...and some tubes I can slap pretty good with no micro phonics whatsoever.

So, at this point, although the EAT 6922 is dead quiet and seems to "work", and the Ediswan works wonderfully, but is micro phonic as all get out. (oh and yea, this is of course a "Platinum" version of the Ediswan.) I'm keeping it in for now and ordering another. I'm not sure what I'll do with the EAT. :puzzled-2: My first EAT went way noisy, this one started off sounding wonderful, it still works, but sounds terrible.

Happy Holidays to everyone!!

[Coppy]

Most of my spare ones 411are 07 09. Replacement gat two are 09 09

Well... My Gat sounded a bit flat so I gave the Holland Mullards I put in a few months ago a little tap. On was very noisy and the other just a little. So in went my old EH6922s. One's a little microphonic the other is fine but the sound is okay again. Think this NOS thing is always a gamble. Maybe better to stick with something new and tested. Guess I'll get Ed to send me a couple of new ones tomorrow.

Happy new year to everyone! :roots::wine::newyears:

Bob

[Rafale]

my GAT is since a few days equipped with EAT 6922 selected.....it is very probably the end of my adventures on NOS territory,they are absolutely magnificent in all the departments....more to come but but by far they are the best 6922 that I listened with my GAT, I tried Tesla, EH, GL, JJ, Mullard Holland.... remain to verify their reliability in the time
btw I have just had a failure on a new set of NOS Mullard in the 'ignition' and I have fear the worst for my amplifier....

[jimtranr]

btw I have just had a failure on a new set of NOS Mullard in the 'ignition' and I have fear the worst for my amplifier....

Hoping the result is not "the worst," Philippe.

[jimtranr]

Well... My Gat sounded a bit flat so I gave the Holland Mullards I put in a few months ago a little tap. On was very noisy and the other just a little. So in went my old EH6922s. One's a little microphonic the other is fine but the sound is okay again. Think this NOS thing is always a gamble. Maybe better to stick with something new and tested. Guess I'll get Ed to send me a couple of new ones tomorrow.

Happy new year to everyone! :roots::wine::newyears:

Bob

Happy new year back to you, Bob.

While I've been tempted from time to time to tube-roll in my PR17, I've had such good luck reliability-and-longevity-wise with first the original-equipment Sovteks and more recently EH's that I've decided to leave well enough alone. While that means foregoing a possible bump in performance, I tend to sleep better at night. :D

[repman]

I have had no trouble with my ET-5 and premature tube failure , I broke it in with the factory tube , switched to a GL 6922, then a EAT -6922 and I have settled in on a NOS Westinghouse which remains my favorite in this pre so far. It has a very involving musicality about it that the EAT or GL did not produce in my setup.

[Coppy]

Happy new year back to you, Bob.

While I've been tempted from time to time to tube-roll in my PR17, I've had such good luck reliability-and-longevity-wise with first the original-equipment Sovteks and more recently EH's that I've decided to leave well enough alone. While that means foregoing a possible bump in performance, I tend to sleep better at night. :D

Jim,

Sounds like a plan that works for me also. CJD really does design their equipment for the available new tube stock so we risk making a negative change to the sound with all this rolling.

Also to all... c-j is closed for the holiday season until Jan 3, 2012. I guess we're on our own until then.

Bob

[Rayooo]

I have had no trouble with my ET-5 and premature tube failure , I broke it in with the factory tube , switched to a GL 6922, then a EAT -6922 and I have settled in on a NOS Westinghouse which remains my favorite in this pre so far. It has a very involving musicality about it that the EAT or GL did not produce in my setup.

This is getting silly, just installed a Telefunken last evening. sounded wonderful for first hour or so. then a noise/crackle developed in right channel. Did the normal testing to confirm....asking for a replacement this morning.
Maybe all I need is to get off this light work schedule this week...next week I won't have so much time to spend listening to music, maybe in some small way a good thing. :scratch2: ... :no:

'looking forward to that NOS Westinghouse! :D

[joeinid]

Rayooo,

Sorry to read about all your troubles. I have a new, spare EH from CJ you can have. Maybe you will have better luck with mine. PM me your address and I'll ship it out.

Joe

[930Blue]

My CJ friends,

I have a CJ ET-3 that developed tube "hiss" after only about 350 hours. From talking to several people it seems like the new CJs, (ET-3, ET-5 and GAT) rarely get 1500 hours out of their tubes before problems occur. I only have anecdotal evidence here so I could be wrong.
Can anyone recommend a truly magical tube for the ET-3? I ordered a new Electro Harmonix tube from CJ today but I would like to experiment with other tubes and I am willing to pay for best performance.

Cheers,

Marc

[bgiliberti]

My CJ friends,

I have a CJ ET-3 that developed tube "hiss" after only about 350 hours. From talking to several people it seems like the new CJs, (ET-3, ET-5 and GAT) rarely get 1500 hours out of their tubes before problems occur. I only have anecdotal evidence here so I could be wrong.
Can anyone recommend a truly magical tube for the ET-3? I ordered a new Electro Harmonix tube from CJ today but I would like to experiment with other tubes and I am willing to pay for best performance.

Cheers,

MarcSorry to hear of your problems. But I really have to wonder about the 350 hours. That does not square with my experience with CJ preamps, which have been so easy on tubes that I feel like I'm being OCD to replace them (once a year) "just in case.' Might there be another issue? Do you leave the preamp on 24/7?

[chessman]

930Blue, welcome aboard! :wave:

[Rafale]

My CJ friends,

I have a CJ ET-3 that developed tube "hiss" after only about 350 hours. From talking to several people it seems like the new CJs, (ET-3, ET-5 and GAT) rarely get 1500 hours out of their tubes before problems occur. I only have anecdotal evidence here so I could be wrong.
Can anyone recommend a truly magical tube for the ET-3? I ordered a new Electro Harmonix tube from CJ today but I would like to experiment with other tubes and I am willing to pay for best performance.

Cheers,

Marc

Hi Marc
tube issue very probably...
Try with a Genalex 6922 or EAT ECC88, more expensive but to my ears even better with an inclusive guarantee

[Rayooo]

My CJ friends,

I have a CJ ET-3 that developed tube "hiss" after only about 350 hours. From talking to several people it seems like the new CJs, (ET-3, ET-5 and GAT) rarely get 1500 hours out of their tubes before problems occur. I only have anecdotal evidence here so I could be wrong.
Can anyone recommend a truly magical tube for the ET-3? I ordered a new Electro Harmonix tube from CJ today but I would like to experiment with other tubes and I am willing to pay for best performance.

Cheers,

Marc

Hello and welcome!

I definitely like the Genelex 6922 and the Westinghouse 6922 (thanks again repman) I am now back to the EAT . (2nd one working fine, first failed)

I also tried a couple Telefunken E88CC, very nice sounding tube, but the two I tried both failed (noise in one channel) so I basically gave up.

[930Blue]

Thanks for the Tube advice. I will give the Genelex and EATs a try.

[joeinid]

930Blue, welcome aboard! :wave:

:welcome2.:

[jimtranr]

Welcome aboard, Marc.

[turntable]

Gotta bring this chestnut up again.

Really noticed the additional tube noise/hiss when I inserted the prem350 into the system.

Back to the prem8a tube amps and still hiss was there ( not as loud) regardless of volume.

Then put in a pair of Telefunken PCC88's and no noise. Pulled out another pair of cj eh 6922's ( lucky I have a few left over from my spare set for the art) and put them into the GAT.

No noise - WTF?

This is 4 pairs of eh 6922's that have started silent and turned noisy. :grumpy: never had these issues with the prem16 nor art and they had a lot more tubes.

[Puma Cat]

Shane,
IIRC, I've read a number of reports of GAT owners who found their tubes became noisy after a relatively short period of use. Could be that GATs are hard on their tubes, after all.

[vintage_tube]

Shane,
IIRC, I've read a number of reports of GAT owners who found their tubes became noisy after a relatively short period of use. Could be that GATs are hard on their tubes, after all.

I have heard the same from an owner I know. He's not happy about it & infact it is ruining his audio frame of mind when he turns his gear on. What do I mean by that -- he now questions whether the system is running optimum at all times or is a tube starting to go south, again.

That's not a happy feeling. He has been in contact with CJ & I don't know what they have suggested/mentioned/etc.

Best

Bob

[Myles B. Astor]

Shane,
IIRC, I've read a number of reports of GAT owners who found their tubes became noisy after a relatively short period of use. Could be that GATs are hard on their tubes, after all.

I still am using my original set.

[Coppy]

Shane,
IIRC, I've read a number of reports of GAT owners who found their tubes became noisy after a relatively short period of use. Could be that GATs are hard on their tubes, after all.

My original set is still quiet. I've tried a few sets of NOS tubes and they've all been or turned noisy. I finally got sick of it and tried all my tubes... the only ones that were dead quiet are the original EH 6922s. Maybe that's the benefit of getting them from c-j, they reject the noisy tubes before sending them to customers.

[turntable]

My original set is still quiet. I've tried a few sets of NOS tubes and they've all been or turned noisy. I finally got sick of it and tried all my tubes... the only ones that were dead quiet are the original EH 6922s. Maybe that's the benefit of getting them from c-j, they reject the noisy tubes before sending them to customers.

All my 4 sets of gone south tubes are cj tubes. Started quiet then noisy. 2 specifically for the GAT and 2 from my spare set ex the art.

I wonder if the voltage makes a difference. Ie. 230-240 vlt. Vs 120 vlt. Are the transformers for 240 vlt spec'd correctly for 240 vlts?

I will contact cj as I am pissed.

[Rayooo]

All my 4 sets of gone south tubes are cj tubes. Started quiet then noisy. 2 specifically for the GAT and 2 from my spare set ex the art.

I wonder if the voltage makes a difference. Ie. 230-240 vlt. Vs 120 vlt. Are the transformers for 240 vlt spec'd correctly for 240 vlts?

I will contact cj as I am pissed.

I for one would sure like to understand what's going on with this...I've been Ok lately..knock-on-wood.

[joeinid]

I for one would sure like to understand what's going on with this...I've been Ok lately..knock-on-wood.


I never had an issue with my GAT or ET5 for that matter. I am actually thinking about replacing my GAT with another one, because I liked it so much.

[vintage_tube]

I will contact cj as I am pissed.

That's ashame -- hope you or the fine folks at cj gets to the bottom of the issue -- they are great components.

Best in your troubleshooting/resolution.:thumbsup:

Bob

[turntable]

I never had an issue with my GAT or ET5 for that matter. I am actually thinking about replacing my GAT with another one, because I liked it so much.

Joe, you never had your cj components in your system long enough to have anything go wrong :D:D:D

[Coppy]

I never had an issue with my GAT or ET5 for that matter. I am actually thinking about replacing my GAT with another one, because I liked it so much.

Good move... :banana:

[joeinid]

Joe, you never had your cj components in your system long enough to have anything go wrong :D:D:D

I was waiting for that :yes:

Good move... :banana:

:thumbsup:

[ronenash]

I had the same problem. CJ mentioned that there was a bad stash of tubes from EH that were turning noisy. They can identify them by the dates. Once I replaced the EH tubes with the Matsushita 7DJ8 I had it working for over a 1000 hours with no problem whatsoever. A friend of mine received a replacement EH6922 from CJ and also worked with it for over 500 hours without a problem.

[turntable]

That's ashame -- hope you or the fine folks at cj gets to the bottom of the issue -- they are great components.

Best in your troubleshooting/resolution.:thumbsup:

Bob

I am sure they will. Lew and the cj team are amongst the nicest in the business.

[joeinid]

I am sure they will. Lew and the cj team are amongst the nicest in the business.

+1 :yes:

[vintage_tube]

I am sure they will. Lew and the cj team are amongst the nicest in the business.

Let's hope it is a specific 'bad' tube batch as ronenash mentions. Now, that would be nice & sweet (for an easy resolution).:thumbsup:

Best

Bob

[ronenash]

I am sure they will. Lew and the cj team are amongst the nicest in the business.

The nicest I have ever met that's for sure. This is one of the reasons for over 20 years now I keep coming back.

[ronenash]

Thought I would provide a bit more information on this one.

I am guessing the noise you are hearing in this case is just white noise with no crackling or breakage noises. The white noise will get stronger as the tube ages until the tube becomes useless. If the noise you are hearing does not match this description then you are looking at a different problem.

Tube noise that matches the above is in most cases a result of disintegration of the coating on the tube filament (the heater wire inside the tube). I believe the scientific explanation for this is that once the coating goes bad stray electrons from the filament are interfering with the normal operation of the tube and causing noise.
This problem with the filament coating can be a result operating the tube at higher filament voltages then the 6.3v the tube is designed for or a defect in the manufacturing of the tube.
I have checked the voltages inside CJ preamps and they are spot on so that leaves us with the manufacturing defect as Lew Johnson mentioned. I think Reflector had this problem for quite a while since I have seen it on Gold Lion tubes as well (GL's are premium EH tubes manufactured at the same factory).
The problem is more noticeable when the tube is used in high gain application such as that in a CJ preamp where no feedback is used which reduces the gain. Using these tube in as driver tubes in a power amp will not be a problem in most cases as the tube is configured to driver the output tubes and not to amplify the signal.

This is a rather technical explanation. I hope I have not gone overboard :)
Anyway, I hope this helps understand what we are experiencing.

[vintage_tube]

Thought I would provide a bit more information on this one.

I am guessing the noise you are hearing in this case is just white noise with no crackling or breakage noises. The white noise will get stronger as the tube ages until the tube becomes useless. If the noise you are hearing does not match this description then you are looking at a different problem.

Tube noise that matches the above is in most cases a result of disintegration of the coating on the tube filament (the heater wire inside the tube). I believe the scientific explanation for this is that once the coating goes bad stray electrons from the filament are interfering with the normal operation of the tube and causing noise.
This problem with the filament coating can be a result operating the tube at higher filament voltages then the 6.3v the tube is designed for or a defect in the manufacturing of the tube.
I have checked the voltages inside CJ preamps and they are spot on so that leaves us with the manufacturing defect as Lew Johnson mentioned. I think Reflector had this problem for quite a while since I have seen it on Gold Lion tubes as well (GL's are premium EH tubes manufactured at the same factory).
The problem is more noticeable when the tube is used in high gain application such as that in a CJ preamp where no feedback is used which reduces the gain. Using these tube in as driver tubes in a power amp will not be a problem in most cases as the tube is configured to driver the output tubes and not to amplify the signal.

This is a rather technical explanation. I hope I have not gone overboard :)
Anyway, I hope this helps understand what we are experiencing.

:applause:

Good clear, concise explanation -- let's hope TT has a bad set of EH's.

Best

Bob

[turntable]

Thought I would provide a bit more information on this one.

I am guessing the noise you are hearing in this case is just white noise with no crackling or breakage noises. The white noise will get stronger as the tube ages until the tube becomes useless. If the noise you are hearing does not match this description then you are looking at a different problem.

Tube noise that matches the above is in most cases a result of disintegration of the coating on the tube filament (the heater wire inside the tube). I believe the scientific explanation for this is that once the coating goes bad stray electrons from the filament are interfering with the normal operation of the tube and causing noise.
This problem with the filament coating can be a result operating the tube at higher filament voltages then the 6.3v the tube is designed for or a defect in the manufacturing of the tube.
I have checked the voltages inside CJ preamps and they are spot on so that leaves us with the manufacturing defect as Lew Johnson mentioned. I think Reflector had this problem for quite a while since I have seen it on Gold Lion tubes as well (GL's are premium EH tubes manufactured at the same factory).
The problem is more noticeable when the tube is used in high gain application such as that in a CJ preamp where no feedback is used which reduces the gain. Using these tube in as driver tubes in a power amp will not be a problem in most cases as the tube is configured to driver the output tubes and not to amplify the signal.

This is a rather technical explanation. I hope I have not gone overboard :)
Anyway, I hope this helps understand what we are experiencing.

Yes Ron. white noise. that is why it dissappears( for a while) when you change to new tubes.

4 sets of cj EH 6922 in less than 11 months of ownership.

As mentioned previously most of my spare ones are 07 09 dates. Replacement gat two are 09 09 .

BTW, how do you check the voltages inside CJ preamps?

cheers

[Hatzudokiseizo]

I have had my GAT for several months and I am on my third set of factory 6922 tubes

The tubes do not fail, but get noisy with tube hiss. I noticed the right channel had got noisy. Lucky I have a set of ten left from my art, however this is not good.

I can't see how you can blame the eh tubes as I have not had these issues with my art/prem 16 in the past.

Anyone else had any tube noise issues?

Hello turntable,

Are your Tubes 6922 in Pair Matching? In my LS16MKII have the JAN Sylvania 6922 in Matching and are very well:D
I have the Sovtec s in Premier 8A and are hard for me in the Sound as well as Electro harmonix
Try the Times with JAN PHiLLIPS 6922 in Matching-Pair and Low Microphonics...
Greets Sounding chris

[ronenash]

BTW, how do you check the voltages inside CJ preamps?

cheers

With a voltmeter on the tube pins when the cover is off. I would not try it if you are not sure what you are doing. You can easily harm the amp by shorting something inside the box.

[rlw3]

the 6922 always seemed to lose its high water mark performance in relatively few hours when i used them in audible illusions 3 preamp, cj ls 16 preamp or as input or driver tubes in my music reference amps. the 6h30p tubes in my act 2.2 are much more consistant-amazingly so in comparison. i am now biased against buying 6922 based gear

[Coppy]

Thought I would provide a bit more information on this one.

I am guessing the noise you are hearing in this case is just white noise with no crackling or breakage noises. The white noise will get stronger as the tube ages until the tube becomes useless. If the noise you are hearing does not match this description then you are looking at a different problem.

Tube noise that matches the above is in most cases a result of disintegration of the coating on the tube filament (the heater wire inside the tube). I believe the scientific explanation for this is that once the coating goes bad stray electrons from the filament are interfering with the normal operation of the tube and causing noise.
This problem with the filament coating can be a result operating the tube at higher filament voltages then the 6.3v the tube is designed for or a defect in the manufacturing of the tube.
I have checked the voltages inside CJ preamps and they are spot on so that leaves us with the manufacturing defect as Lew Johnson mentioned. I think Reflector had this problem for quite a while since I have seen it on Gold Lion tubes as well (GL's are premium EH tubes manufactured at the same factory).
The problem is more noticeable when the tube is used in high gain application such as that in a CJ preamp where no feedback is used which reduces the gain. Using these tube in as driver tubes in a power amp will not be a problem in most cases as the tube is configured to driver the output tubes and not to amplify the signal.

This is a rather technical explanation. I hope I have not gone overboard :)
Anyway, I hope this helps understand what we are experiencing.

Ron,

Some folks seem to prefer the Gold Lions. My EH 6922s are fine at the moment... quiet and sound good. The last time I started tube rolling I regretted it but... if they are the best of the EH's do you prefer the GLs?

Thanks,
Bob

[ronenash]

Ron,

Some folks seem to prefer the Gold Lions. My EH 6922s are fine at the moment... quiet and sound good. The last time I started tube rolling I regretted it but... if they are the best of the EH's do you prefer the GLs?

Thanks,
Bob

Bob,
I found the GL to be a bit better than the EH but their biggest advantage is more consistent quality. The best 6922 tube I have used to date is the Matsushita 7DJ8. I found them to be better than the EH in everyway and Upscale has them for a reasonable price.

[Myles B. Astor]

Bob,
I found the GL to be a bit better than the EH but their biggest advantage is more consistent quality. The best 6922 tube I have used to date is the Matsushita 7DJ8. I found them to be better than the EH in everyway and Upscale has them for a reasonable price.

One day I'm going to find that pair of Tele ECC188/7308s and put them in the GAT. One day also will get a pair of CCA to try when have some dough.

[medward0]

Thanks for the thread here, guys. I've been wondering if there's been something wrong with my pre as it does go through tubes. Sounds like it is pretty normal.

I've had the pre for about a year and I am now on my 5th tube. The pre is only on when I am listening to it. I'm guessing that I have > 600 hours total on the unit by now. Unit is well ventilated and all that.

It does sound like some amount of tube "rush" is normal, so I may have just assumed that the tube was bad, when it wasn't...just those stray electrons bouncing about in advance of the tube's ultimate demise.

I've tried CJ EH 6922, EH Gold 6922, & GL. I loved, loved the GL's midrange, but it went crackly on me in about a month. The last EH Gold lasted maybe two months before getting noisey.

Oh, the stock 6922s in my ET250S are factory and are dead quiet still after a year or so.

Sigh...tubes are glorious sounding indeed, but kinda high maintenance.

Thanks for the tips about the mfg date.

[Coppy]

One day I'm going to find that pair of Tele ECC188/7308s and put them in the GAT. One day also will get a pair of CCA to try when have some dough.

Well, I just ordered a couple of NOS Tele ECC88s for Mr. GAT. Diamonds, gold pins and all. Found them on sale at Tube Depot last week. Maybe I'll learn what all the fuss is about. They had better be dead quiet.

Wish me luck...
Bob

[Rayooo]

Well, I just ordered a couple of NOS Tele ECC88s for Mr. GAT. Diamonds, gold pins and all. Found them on sale at Tube Depot last week. Maybe I'll learn what all the fuss is about. They had better be dead quiet.

Wish me luck...
Bob

I've been over there at TDepot a few times now pondering buying a couple of those on-sale Tele ECC88s...I guess it's inevitable. :sigh:

[Coppy]

Better hurry. The sale expired yesterday but since I've bought other stuff, they gave me the price today. They seem like good folks to deal with.

[Puma Cat]

Thanks for the thread here, guys. I've been wondering if there's been something wrong with my pre as it does go through tubes. Sounds like it is pretty normal.

I've had the pre for about a year and I am now on my 5th tube. The pre is only on when I am listening to it. I'm guessing that I have > 600 hours total on the unit by now. Unit is well ventilated and all that.

It does sound like some amount of tube "rush" is normal, so I may have just assumed that the tube was bad, when it wasn't...just those stray electrons bouncing about in advance of the tube's ultimate demise.

I've tried CJ EH 6922, EH Gold 6922, & GL. I loved, loved the GL's midrange, but it went crackly on me in about a month. The last EH Gold lasted maybe two months before getting noisey.

Oh, the stock 6922s in my ET250S are factory and are dead quiet still after a year or so.

Sigh...tubes are glorious sounding indeed, but kinda high maintenance.

Thanks for the tips about the mfg date.

Curious as to what is going on as I've had my Premier 17 almost two years without any tubes going bad whatsoever. Also, the Ediswan input 6922s in my LP70S power amp will be three years old in January, still no issues.

[Rayooo]

Better hurray. The sale expired yesterday but since I've bought other stuff, they gave me the price today. They seem like good folks to deal with.

haha yea, I hopped over there...the sale had expired. I called them and the person I spoke with said he'd gotten approval earlier today to sell a set at the sale price. I guess we know who that happy customer is. :yes:

So I've got a set on order as well at the good price. I've purchased quite a few tubes over the years from them.

Oh yea, a good outfit for sure. I still enjoy watching their build-your-own-guitar-amp videos now and then,

[Joe Appierto]

Glad you were able to get them at the sale price, Bob. You're in for a treat, the Telefunken ECC88s are just plain excellent.

Edit: You too, Ray. Think I had a brain fart there. :o

[medward0]

Curious as to what is going on as I've had my Premier 17 almost two years without any tubes going bad whatsoever. Also, the Ediswan input 6922s in my LP70S power amp will be three years old in January, still no issues.

Thx, Puma Cat. Yea, me too. And a bit worried, I must say. :sigh:

[Puma Cat]

Thx, Puma Cat. Yea, me too. And a bit worried, I must say. :sigh:

It certainly sounds unusual. I think Rayooo was saying he'd been through a fair no. of tubes on his ET-5 as well. Something with the current ET/GAT topology perhaps?

My CT-5 currently has the Reflektor 6H30 DR "super tube" which is reputedly reknown for going tens of thousands of hours. My understanding is that one of it's primary requirements from the Soviet gov't was extreme durability.

[Myles B. Astor]

Well I hope the DRs are better than the EBs. I've had three EBs go in my ART amps. I did try the DRs but I really don't think they sounded better than the EBs. In my sytem, the DRs were among other things definitely edgier.

So far the latest ERs seem to be holding up. I'm beginning to think that many of these Russian tubes have real reliability and longetivity issues
:(

[chessman]

It certainly sounds unusual. I think Rayooo was saying he'd been through a fair no. of tubes on his ET-5 as well. Something with the current ET/GAT topology perhaps?

My CT-5 currently has the Reflektor 6H30 DR "super tube" which is reputedly reknown for going tens of thousands of hours. My understanding is that one of it's primary requirements from the Soviet gov't was extreme durability.

Stephen, where did you buy your DR's? I have been thinking about trying them in my BAT VK-52 SE in lieu of the regular 6H30's.

[Myles B. Astor]

Stephen, where did you buy your DR's? I have been thinking about trying them in my BAT VK-52 SE in lieu of the regular 6H30's.

I got mine from a tube dealer that I've dealt with before from Turkey. The prices were reasonable and the tubes came in two or so weeks from Russia. I'm not sure the one's sold by Parts Connexion are real as they look different from any other DR and don't sound that good to me.

I also picked four up on audiogon from someone who had just sold their BAT gear and was also selling their backup tubes.

The DR IMHO might work better in a system that leans to the dark side but definitely wouldn't use them in a lean system.

[Puma Cat]

Stephen, where did you buy your DR's? I have been thinking about trying them in my BAT VK-52 SE in lieu of the regular 6H30's.

Dang, Randy, I'll have to go back look, I don't remember off the top of my head.

[Puma Cat]

Randy,
Actually, Myles just reminded me...it was Part Connexion.

All I can say is that mine improved the sound of my CT-5, giving it a slightly warmer tone and a fuller sound than the stock EH's.

[ronenash]

Randy,
Actually, Myles just reminded me...it was Part Connexion.

All I can say is that mine improved the sound of my CT-5, giving it a slightly warmer tone and a fuller sound than the stock EH's.

Maybe I should try the DR's in my ACT2. Never thought of doing so.

[Joe Appierto]

Maybe I should try the DR's in my ACT2. Never thought of doing so.

They've certainly gone up a lot in price. I seem to remember buying them from Conus Audio (http://www.conusaudio.com/) maybe seven years ago for $50 each, now they have them listed for $175. Jeez. :scratch2:

I've had the regular 6H30π-EB version in the Pr. 140 as it breaks in but maybe it's time to try them again. At the time the DR's seemed a little smoother but also a bit more detailed. Previously, it wasn't a night'n'day kind of difference but with the new caps, it might be another story.

[vintage_tube]

Getting back to the GAT/ET5 -- any interest in the CJ crowd with GL Reissue 6922's??? Have some in my stash that I was going to use in a Sonic Frontiers SFCD-1 player & never did.

Best

Bob

[vintage_tube]

Getting back to the GAT/ET5 -- any interest in the CJ crowd with GL Reissue 6922's??? Have some in my stash that I was going to use in a Sonic Frontiers SFCD-1 player & never did.

Best

Bob

Guess not.:scratch2:

Bob

[Myles B. Astor]

They've certainly gone up a lot in price. I seem to remember buying them from Conus Audio (http://www.conusaudio.com/) maybe seven years ago for $50 each, now they have them listed for $175. Jeez. :scratch2:

I've had the regular 6H30π-EB version in the Pr. 140 as it breaks in but maybe it's time to try them again. At the time the DR's seemed a little smoother but also a bit more detailed. Previously, it wasn't a night'n'day kind of difference but with the new caps, it might be another story.

The Conus and Parts Connexion 6H30s are the same. They're not the same color lettering as any other 6H30 I've had.

[Joe Appierto]

The Conus and Parts Connexion 6H30s are the same. They're not the same color lettering as any other 6H30 I've had.

I did try the 6H30π-DR's yesterday in the PR. 140. I don't know if it's the new Teflon caps or just me talking myself into it, but this time around I noticed a big difference between the two. The -DR's are superior in just about every way: dynamics, clarity, transparency, timbre and frequency extremes.

This is a picture of one the -EB's I was using on the left and the -DR on the right.

http://x55.xanga.com/5c7e017621532283381751/o225987189.jpg

The -DR looks like what they have at both vendors mentioned. As far as the innards go, the -EB and -DR look the same. In an older post by Victor Khomenko at BAT on the Audio Asylum, he said the -DR's were tubes selected for military applications and had better specifications than the -EB's.

They are awfully expensive.

[Puma Cat]

I did try the 6H30π-DR's yesterday in the PR. 140. I don't know if it's the new Teflon caps or just me talking myself into it, but this time around I noticed a big difference between the two. The -DR's are superior in just about every way: dynamics, clarity, transparency, timbre and frequency extremes.

This is a picture of one the -EB's I was using on the left and the -DR on the right.

http://x55.xanga.com/5c7e017621532283381751/o225987189.jpg

The -DR looks like what they have at both vendors mentioned. As far as the innards go, the -EB and -DR look the same. In an older post by Victor Khomenko at BAT on the Audio Asylum, he said the -DR's were tubes selected for military applications and had better specifications than the -EB's.

They are awfully expensive.

Joe, your experiences with the DRs parallel mine exactly in my CT-5, interestingly enough. I also noticed a fuller, more natural presentation than the non-DR tubes.

[Coppy]

Glad you were able to get them at the sale price, Bob. You're in for a treat, the Telefunken ECC88s are just plain excellent.

Edit: You too, Ray. Think I had a brain fart there. :o

Joe and Ray...

Got the Tele ECC88s today. Listened to some music with the EH6922s in for comparison then plugged in the Teles. One has a very low level, just the smallest bit of hum but do they sound terrific. I have to plant my ear on the speaker to hear the hum but the increased transparency is all over the room at all volume levels. Maybe all this gets better with some break-in time.

Ray... let me know how yours sound. I'm really impressed with the increase in low volume transparency. Still plenty of bottom end. I'm using my PR350 to start as it tends to be a bit more ruthless with detail. Have a meeting tonight so tomorrow will be the trial with the LP140s.


Bob
:music:

[Puma Cat]

Joe and Ray...

Got the Tele ECC88s today. Listened to some music with the EH6922s in for comparison then plugged in the Teles. One has a very low level, just the smallest bit of hum but do they sound terrific. I have to plant my ear on the speaker to hear the hum but the increased transparency is all over the room at all volume levels. Maybe all this gets better with some break-in time.

Ray... let me know how yours sound. I'm really impressed with the increase in low volume transparency. Still plenty of bottom end. I'm using my PR350 to start as it tends to be a bit more ruthless with detail. Have a meeting tonight so tomorrow will be the trial with the LP140s.

Bob
:music:

I totally understand that...

[Rayooo]

Joe and Ray...

Got the Tele ECC88s today. Listened to some music with the EH6922s in for comparison then plugged in the Teles. One has a very low level, just the smallest bit of hum but do they sound terrific. I have to plant my ear on the speaker to hear the hum but the increased transparency is all over the room at all volume levels. Maybe all this gets better with some break-in time.

Ray... let me know how yours sound. I'm really impressed with the increase in low volume transparency. Still plenty of bottom end. I'm using my PR350 to start as it tends to be a bit more ruthless with detail. Have a meeting tonight so tomorrow will be the trial with the LP140s.


Bob
:music:

I didn't get theTeles ordered in time for yesterday's shipment, they should arrive tomorrow (Fri) ...and on a related note the 20.7s arrived today, so I'm in the process of getting them setup. I guess the smart thing to do would be to put some hours on the 20.7s with the stock tubes, and then do a switch to the Teles. Not that the smart thing is what I'll necessarily do, but at least I can talk about it. :D

[joeinid]

Ray,

I am happy and excited for you. I bet they will sound awesome. Congratulations.

[Rayooo]

Ray,

I am happy and excited for you. I bet they will sound awesome. Congratulations.

Thanks Joe, I sure hope they sound good, as they are so big, heavy and cumbersome to move around, it might just be easier to sell them with the house and move somewhere else if I ever decide I want new speakers. :D

I posted a few pix over there in the MLogan and Magnepan room.

[turntable]

Here is the response from Lew at cj regarding the 6922's and issues re the GAT on tube life.

The 1500 hour number is just a rule of thumb for pretty much any of the miniature tubes. Much more than that and you will probably find sound quality degrading (typically a softening of highs and blurring of transients). You may also find issues with the tube going noisy. In any case, there is nothing particularly unusual in the way the tubes are used in the GAT (other than the absence of feedback - but that is the same as in the ART).

All I know for a fact, I got a lot more useful life from 6922's in my prem 16 and ART pre amps. Either I am extremely unlucky or

[turntable]

One more cj 6922 has just gone noisy. This one barely lasted 2 months:tears:

Any ideas guys? Fwiw - my unit is 220-240 export unit and Australia is 240 vlts sometimes up to 250vlts

If this does not improve, I will be forced to look at other pre amp alternatives.

Cheers

[Myles B. Astor]

Here is the response from Lew at cj regarding the 6922's and issues re the GAT on tube life.



All I know for a fact, I got a lot more useful life from 6922's in my prem 16 and ART pre amps. Either I am extremely unlucky or

Think a little of both. :scratch2: I'm still on my original set of 6922 in my GAT. OTOH, how many hours a week do you put on the tubes.

Tubes are beginning to be a real PITA. Have had more of the small signal tubes failing-esp. ECC83s. Only one found reliable is the re-issue Tungsol. And I've had issues with those 6H30 "supertubes" in the ART; two died within six months. Lately have been luckier and tubes have been lasting longer.

[turntable]

Think a little of both. :scratch2: I'm still on my original set of 6922 in my GAT. OTOH, how many hours a week do you put on the tubes.

Tubes are beginning to be a real PITA. Have had more of the small signal tubes failing-esp. ECC83s. Only one found reliable is the re-issue Tungsol. And I've had issues with those 6H30 "supertubes" in the ART; two died within six months. Lately have been luckier and tubes have been lasting longer.

Hi Myles. My tubes are on around 35-40 hours per week on average.

No real issues with tubes failing except for the GAT pre amp - I have never had a small tube go on my amps.

I think you need to clone those 2 x 6922's you have on your GAT:yes:

[lotus340r]

I had a stock EH tube go back in March. Replaced them both with Genalex Gold lions. Was on Holiday for most of April. Now the left channel has gone this time with intermittent crackling. Maybe i've just been really unlucky.

[Rayooo]

Back in January this year, I bought a couple 6922 SIEMENS WEST GERMANY 1974 "SILVER-SHIELD" A-FRAMES.

These, knock-on-wood have been solid ever since, and they sound pretty good also.

Pretty bad when ya get 4 months from a set of tubes and it's an improvement! :)

[rlw3]

What is the consensus on 6922s? which ones are worthy of purchase? just broke my promise to myself and bought an lp275 which is actually on its way to me after being flogged around on 2 lp140 purchases.( i was going to avoid 6922s) i have used 6922s that were in my music reference amps-can they be used in the driver positions?

[ronenash]

Congrats on the LP275. A super amp in every way. I am sure you will love it.
Not sure I understand your question about the 6922 in driver position. Use the tube cj designed the amp for.

[lotus340r]

Congrats ray, where did you get your lp275 from ?

[rlw3]

Congrats on the LP275. A super amp in every way. I am sure you will love it.
Not sure I understand your question about the 6922 in driver position. Use the tube cj designed the amp for.

i am asking if used as apposed to new 6922s can be placed in the 2 driver tubes position/ wondering if driver tubes are non critical to sound quality in this amp so that best sounding 6922s are in input position and "lesser" tubes are used as the drivers. thanks

[rlw3]

Congrats ray, where did you get your lp275 from ?

Rich, got the 275 from a real great guy on agon(not all are $#*&@) there is another one listed right now

[lotus340r]

Katli have a set i understand.

[rlw3]

The katli were discribed to me to be in very good condition,great cosmetics,normal usage. Mine were barely used, 100hrs. I get the honor of Teflon break in. If it wasn't for the California sales tax I would have gone for them.

[turntable]

What is the consensus on 6922s? which ones are worthy of purchase? just broke my promise to myself and bought an lp275 which is actually on its way to me after being flogged around on 2 lp140 purchases.( i was going to avoid 6922s) i have used 6922s that were in my music reference amps-can they be used in the driver positions?

Awesome!!

Pic's when you have them in your hot hands :thumbsup:

[ronenash]

Rich, got the 275 from a real great guy on agon(not all are $#*&@) there is another one listed right now

Ray,
Driver tube are less critical in some ways but just as critical in others. Noise wise a driver tube is much less likely generate noticeable noise since it does not provide much gain. A tube that sounds noisy as an input tube can work perfectly fine as a driver/phase splitter tube.
On the other hand it will influence the sound just as much and you can clearly hear differences between good ones and mediocre ones.
Some tube that I tried and worked very well in my LP125mSE are:
Matsushita 7DJ8 - Great tube, detail, lushness, good price.
Phillips PCC88 - Similar to the Matsushita but less warm (more natural) in the mids.
6N23p-EV - Very good tone, very reliable if you get them from a good source.

Tubes that did not work well:
Gold Lion 6922 - Started flashing after a while when the amp was turned on. Could not take the initial high voltage on the Anode.
Amperex 6DJ8 A-Frame getter - Same as above.
Both of the above tube are good tubes especially the Amperex which is a terrific tube that I use elsewhere but are not a robust as the Matsushita, Phillips or 6N23p

Hope this helps.

[lotus340r]

The katli were discribed to me to be in very good condition,great cosmetics,normal usage. Mine were barely used, 100hrs. I get the honor of Teflon break in. If it wasn't for the California sales tax I would have gone for them.

Thanks a lot Ray.

Anyway, what a result .... as turntable says, please post some pics and interested to hear your impressions too.

[microstrip]

I would be very interested in knowing the differences between the LP275m and the new ART amplifiers - except for the type of input tube and driver they look very similar.

[ronenash]

They have identical output topologies. The input and driver stages are different. In the ART CJ moved to a very simple and basic input stage that includes one triode M8080 for input gain stage and one 6H30 used as a phase splitter. They use the same topology in all their current amplifiers (Classic, LP125 and ART).
The LP275 used parallel triode sections for gain and phase splitter. Apparently this design was dumped by CJ because it resulted in losing some of the purity of the sound and made the amplifiers sensitive to tubes that have un-matched triode sections.

I think over the years CJ has made the power supply sections of their amps more sophisticated and simplified the actual amplification circuits to the bare minimum. Today ~80% of the parts in the their amplifiers are in the power supply. This is very noticeable in their preamps, even more so than the power amps.

[Myles B. Astor]

I would be very interested in knowing the differences between the LP275m and the new ART amplifiers - except for the type of input tube and driver they look very similar.

The only difference between the two amplifiers is the driver stage. But apparently the change in impedance makes for a big sonic difference :)

[microstrip]

Thanks. I could see that the LP275 used three 6922. This means that cj abandoned the 6h30 in the gain section for the GAT, replacing it with a 6922 and started using it in the driver section of the ART. All in the name of better sounding music. :music:

[plurn]

One more cj 6922 has just gone noisy. This one barely lasted 2 months:tears:

Any ideas guys? Fwiw - my unit is 220-240 export unit and Australia is 240 vlts sometimes up to 250vlts

If this does not improve, I will be forced to look at other pre amp alternatives.

Cheers

Hi Turntable,

Did you ever find a way to resolve this issue - or are you still going through tubes like tic tacs?

I am also in Sydney with the same high mains voltage levels and was considering getting one of the current cj preamps but this is quite a worry.

Some ideas:

I have seen some cj equipment that says 240v (not gat) and others (like your gat) that says 220-240v. Perhaps with the export gat they are wiring them up for 220v instead of 240v? cj might be able to advise on this - though I expect they would have mentioned something about this last time you contacted them if there was anything to it. I understand on some of the other cj devices this is easily changeable by a technician by changing where some of the wires are soldered in the power supply. I don't know if the power transformers in the gat support this.

Not sure if it would change the sound quality, but it might be worth trying a 240v to 220v step down transformer (which drops 240v to about 220v and so would drop 250v down to about 230v). Don't know if I am allowed to link to one but they are sold in Australia by a respected company - search for european step down 240-220V. Various wattages available. Would be a shame if something like this is needed for a device that retails and is supported in Australia though.

Were you ever able to measure the tube heater voltage? I am somewhat handy with a multimeter if you would like some assistance with this.

Anthony

[ronenash]

Anthony,

The heater voltage supply in the GAT/ET5 is regulated so a change in line voltage will not effect it. If the line voltage will be a bit higher it will only cause the regulator to dissipate a bit more heat.

I suspect the actual tubes were at fault in this case. EH had a whole manufacturing series that turned noisy after a few hundred hours of use.

It would be good to hear form turntable how this turned out.

Ron

[plurn]

Hi Ron,

Good to know about the regulator - thanks.

Regarding the EH tubes, I got the impression it was an issue for any of the tubes Turntable tried - though not sure if he tried anything other than EH tubes. This is a long thread so I don't quite remember.

Hoping to hear from Turntable too. Would be good if the issue is resolved.

Anthony

[turntable]

Hi Guys

Did the noise issue with the GAT get resolved - well no.

Just tonight another EH 6922 went noisy. I am now down to my last 2 cj EH 6922's.

I have gone through I think about 12.

I was thinking about getting a pair of Telefunken E88CC/6922's but with several months per set, probably not great value.

How does Cryo treatment on the tubes do for reliability and sound?


BTW, Lew did tell me a while back that the plate voltage should be around 85 Volts (say + or - 5 Volts), and the cathode very close to 2.1 volts. If the voltages are right, then the tubes are operating correctly.

I do need to take my GAT to the the tech to get this measured now that I am down to my last two tubes.

cheers

[Myles B. Astor]

Hi Guys Did the noise issue with the GAT get resolved - well no. Just tonight another EH 6922 went noisy. I am now down to my last 2 cj EH 6922's. I have gone through I think about 12. I was thinking about getting a pair of Telefunken E88CC/6922's but with several months per set, probably not great value. How does Cryo treatment on the tubes do for reliability and sound? BTW, Lew did tell me a while back that the plate voltage should be around 85 Volts (say + or - 5 Volts), and the cathode very close to 2.1 volts. If the voltages are right, then the tubes are operating correctly. I do need to take my GAT to the the tech to get this measured now that I am down to my last two tubes. cheers

My first two tubes lasted forever. Second pair, not so long before went hissy. New pair's been just fine. I think the issue was with the Ruskie tubes not cj gear. I think they were selling crap. Have you bought a pair recently?

[turntable]

My first two tubes lasted forever. Second pair, not so long before went hissy. New pair's been just fine. I think the issue was with the Ruskie tubes not cj gear. I think they were selling crap. Have you bought a pair recently?

Hi Myles

I have been living off my spare set of ART tubes as I had 10.

Have you bought the new ones from cj or just garden variety from tube store or similar?

Cheers

[ronenash]

Hi Guys

Did the noise issue with the GAT get resolved - well no.

Just tonight another EH 6922 went noisy. I am now down to my last 2 cj EH 6922's.

I have gone through I think about 12.

I was thinking about getting a pair of Telefunken E88CC/6922's but with several months per set, probably not great value.

How does Cryo treatment on the tubes do for reliability and sound?


BTW, Lew did tell me a while back that the plate voltage should be around 85 Volts (say + or - 5 Volts), and the cathode very close to 2.1 volts. If the voltages are right, then the tubes are operating correctly.

I do need to take my GAT to the the tech to get this measured now that I am down to my last two tubes.

cheers

Telefunken tubes were highly regarded in the 50s and 60s. Back then tube amps were normally very rolled off in the treble because of the quality of the coupling capacitors of the day. The Telefunken had very pronounced treble which balanced things. The Telefunken does not match well with modern tube gear. They sound strident and cause listening fatigue after a while IMO. people pay serious money for them only to find out that they don't like them.
A Gold Lion 6922 would be a much better match for the GAT. The Matsushita 7DJ8 is also great, warm, transparent and images very good.

[Myles B. Astor]

Telefunken tubes were highly regarded in the 50s and 60s. Back then tube amps were normally very rolled off in the treble because of the quality of the coupling capacitors of the day. The Telefunken had very pronounced treble which balanced things. The Telefunken does not match well with modern tube gear. They sound strident and cause listening fatigue after a while IMO. people pay serious money for them only to find out that they don't like them.
A Gold Lion 6922 would be a much better match for the GAT. The Matsushita 7DJ8 is also great, warm, transparent and images very good.

That's not been my experience with the Tele ECC801S vs. any new 12AT7 (the only other tube that was competitive was the NOS Mullard 4024).

And I'm not a great fan of most new tubes. QC aside-which I've found to be horrible for many-they really lack most things. Yes, they are dynamic but that's about it. The only GL I've heard are the GL 12AX7s and they did nothing for me.

[turntable]

Telefunken tubes were highly regarded in the 50s and 60s. Back then tube amps were normally very rolled off in the treble because of the quality of the coupling capacitors of the day. The Telefunken had very pronounced treble which balanced things. The Telefunken does not match well with modern tube gear. They sound strident and cause listening fatigue after a while IMO. people pay serious money for them only to find out that they don't like them.
A Gold Lion 6922 would be a much better match for the GAT. The Matsushita 7DJ8 is also great, warm, transparent and images very good.

Gotta say I am with Myles on this. None of the telefunken's have had any of the traits you mention.

My telefunken 12ax7's I used with my MCintosh c2300 were sensational - open, extended, tight bass superb voicing and quiet as a mouse.

My telefunken PCC88 I have used with the GAT are also superb, however I actually got a little better treble extension from the stk EH 6922's. I should pop them in again to re-listen

cheers


That's not been my experience with the Tele ECC801S vs. any new 12AT7 (the only other tube that was competitive was the NOS Mullard 4024).

And I'm not a great fan of most new tubes. QC aside-which I've found to be horrible for many-they really lack most things. Yes, they are dynamic but that's about it. The only GL I've heard are the GL 12AX7s and they did nothing for me.

[Myles B. Astor]

Hi Myles I have been living off my spare set of ART tubes as I had 10. Have you bought the new ones from cj or just garden variety from tube store or similar? Cheers

From cj since they test them in circuit.

[ronenash]

To each his own taste. The Tele's never sounded like live music to me. I only tried their 12at7 and 6922 variants so my experience is based on these tubes only.

[ronenash]

BTW, I think some of the current production power tubes are just as good or better their NOS counterparts. Some truly great power tubes IMO are the GL KT88, Tung-Sol KT120. I find these to be extremely reliable and great sounding.
Both are definitely better than the GE 6550A and GEC KT88 I have tried.

[turntable]

BTW, I think some of the current production power tubes are just as good or better their NOS counterparts. Some truly great power tubes IMO are the GL KT88, Tung-Sol KT120. I find these to be extremely reliable and great sounding.
Both are definitely better than the GE 6550A and GEC KT88 I have tried.

Agree, the Tung-Sol 6550 is also wonderful. I prefer it to the KT120.

NOS, too expensive for 16 power tubes

[Myles B. Astor]

BTW, I think some of the current production power tubes are just as good or better their NOS counterparts. Some truly great power tubes IMO are the GL KT88, Tung-Sol KT120. I find these to be extremely reliable and great sounding. Both are definitely better than the GE 6550A and GEC KT88 I have tried. Yeah I guess we don't agree. There was no better tube in cj power amps than the original Gold Lion KT88. Just as there was no better tube in Jadis amps than the original KT77.

[Coppy]

I've had good luck and sound with the EC88 Tele's in the GAT. Maybe it's the particular model or year made. Having them stopped my tube rolling entirely. I seem to remember Jeff at c-j liking them as well.

Bob

[turntable]

I've had good luck and sound with the EC88 Tele's in the GAT. Maybe it's the particular model or year made. Having them stopped my tube rolling entirely. I seem to remember Jeff at c-j liking them as well.

Bob

Thanks, I am very temped. Upscale has them at a reasonable price - comparatively of course.

[Myles B. Astor]

Thanks, I am very temped. Upscale has them at a reasonable price - comparatively of course.

At least you know the tubes are really NOS, not the crap that people pull and try to pass off as NOS.

[Joe Appierto]

At least you know the tubes are really NOS, not the crap that people pull and try to pass off as NOS.

Point well made.

[turntable]

At least you know the tubes are really NOS, not the crap that people pull and try to pass off as NOS.

Yes, some could pass off as NOC. New old crap

[turntable]

After Upscale taking over two weeks to process my order, I received the telefunken E88CC's.

Very nice indeed. Has all the extension the stk EH's have, more open midrange, a nice tight bass and grainless.

Early days, but me thinks these are excellent and worth the premium - finger crossed they last.

[plurn]

Hi Guys

Did the noise issue with the GAT get resolved - well no.

Just tonight another EH 6922 went noisy. I am now down to my last 2 cj EH 6922's.

I have gone through I think about 12.

...


BTW, Lew did tell me a while back that the plate voltage should be around 85 Volts (say + or - 5 Volts), and the cathode very close to 2.1 volts. If the voltages are right, then the tubes are operating correctly.

I do need to take my GAT to the the tech to get this measured now that I am down to my last two tubes.

cheers

I have measured voltages on my Australian market 220-240V 50/60Hz ET5. There are solder points on the tube daughter-card under the tube holder that make it easy to measure voltages.

mains voltage at time of measurement 248V 50Hz

pin 1 83.3V (plate, triode 2)
pin 3 2.028V (cathode, triode 2)
pin 5 6.57V (heater - should be 6.3V)
pin 6 83.1V (plate, triode 1)
pin 8 2.054V (cathode, triode 1)

Plate and cathode voltages look fine, but the heater voltage is a bit high. ET5 was fully warmed up at time of measurement.

If this is a problem, I might need to look into a 7DJ8 (7V or 7.3V) tube until it is resolved.

Anthony

[plurn]

For comparison, I have an online double conversion uninterruptible power supply for my computers that allows me to set the output voltage to any of 220V 225V 230V and 240V so I measured the ET5 plugged into the UPS set at 220V.

mains voltage at time of measurement 221V 50Hz

pin 1 83.5V (plate, triode 2)
pin 3 2.06V (cathode, triode 2)
pin 5 6.58V (heater - should be 6.3V)
pin 6 82.9V (plate, triode 1)
pin 8 2.086V (cathode, triode 1)

So looks very similar to when receiving 248V. I measured similar heater voltage at 230V mains. So doesn't look like the mains voltage makes any difference (confirming ronenash's comments about regulation).


Extra info. Tube manufacturers seem to specify the acceptable heater voltage range for 6922 as:

Limited values

Heater voltage, v,
not less 6.0
not more 6.6

So my ET5 is within that - just on the high side. It is about 4.4% above the nominal 6.3V which is not a huge amount. I have also read that "operation above allowable range deteriorates the very long term emission life to perhaps 60% or so for every 5% above nominal voltage". So my ET5 is not quite at 5% above nominal so tube life might be reduced a little bit.

Considering those limits, if the relative limits of a 7DJ8 are similar - then it is probably better to use 6922 than 7DJ8 as the 7DJ8 might be under volted and I have since read that under voltage can be very bad for tube life due to potential of cathode poisoning. It can be worse for tube life than over voltage.

The sources for what I have read about how voltage relates to tube life are not authoritative - so they could be wrong. Interesting though.

While I am measuring voltages - I'll add the following which some people might find useful (well I would) and it is not in the ET5 specs:

conrad johnson ET5 power usage measurements:

with mains at 248V 50Hz
about 3 watts idle
power factor while idle 0.49
about 25-30 watts in use
VA 34.6 watts (while power use was about 26)
power factor 0.75
R power 22.8


with mains at 221V 50Hz
2.71 watts idle
power factor while idle 0.49
23 watts in use
VA 30 watts (while power use was about 23)
power factor 0.76
R power 19.4

Anthony

[turntable]

Hi Anthony

Nice measurements and good to know that the voltage does not seen to effect the measures.. I guess it proves that tubes are the problem vs the cj preamp

Cheers

[ronenash]

High heater voltage will shorten tube life considerably. I am not sure why CJ chose this design in the their current line of preamp (ET3, ET5, GAT). The ACT2 AND Premier 14 that I own do not have this problem. If anything I would pull down the heater voltage to 6.0v which is what I chose in my own DIY designs. The tubes last longer and there is no hit in sound quality.
A 7dj8 is definitely a better match for a 6.5v heater voltage IMO.

[plurn]

I sent the measurements to the the conrad johnson service department, and mentioned I had read a lot of reports of tubes going noisy quite quickly in current model cj preamplifiers, and that the previous owner of my ET5 had a tube go noisy within 100 hours. I asked them if my ET5 was ok or if it needed adjustment.

They indicated that all of the measurements are within their design specifications and no adjustments are needed.

They added a note that I may want to experiment with some NOS tubes: Russian, 6n23 and Philips, PCC88

The first one is the robust type that I have seen recommended for preamplifiers that are hard on tubes. PCC88 is equivalent of 7dj8 (7 or 7.3V?).

I received an assortment of tubes from the previous owner of my ET5 so I think I am fine for a while. Will probably give those suggested tubes a go once the goodness has left my existing tubes.

Anthony

[plurn]

I have been using an electro-harmonix gold 6922 (date mark 1212) in my ET5 and have been recording the hours used. By about 345 to 350 hours of use, I have noticed it has started to produce a constant even hiss (not sure if this is what is referred to as tube rush?) which can be heard about 2 feet away from my speakers, even at low volumes on the ET5.

My speakers are quite inefficient at 86dB/2.83v and my power amplifier has 26dB gain. My system is less susceptible to this issue than it might be for others with more efficient speakers. I expect people with more efficient speakers would hear this hiss at the listening position and would consider these tubes failed.

350 hours is really not a lot of time for a tube to last.

I'll keep using this one, for a while anyway, as in my system it still sounds good at the listening position and I want to see how it progresses.

Anthony

[ronenash]

This is indeed the infamous tube rush. It will grow loader as time passes.

[Myles B. Astor]

I sent the measurements to the the conrad johnson service department, and mentioned I had read a lot of reports of tubes going noisy quite quickly in current model cj preamplifiers, and that the previous owner of my ET5 had a tube go noisy within 100 hours. I asked them if my ET5 was ok or if it needed adjustment. They indicated that all of the measurements are within their design specifications and no adjustments are needed. They added a note that I may want to experiment with some NOS tubes: Russian, 6n23 and Philips, PCC88 The first one is the robust type that I have seen recommended for preamplifiers that are hard on tubes. PCC88 is equivalent of 7dj8 (7 or 7.3V?). I received an assortment of tubes from the previous owner of my ET5 so I think I am fine for a while. Will probably give those suggested tubes a go once the goodness has left my existing tubes. Anthony

I had no issues with my first set of tubes. The second went noisy but the third set of tubes are doing just fine.

I wouldn't waste my money or time with the 7DJ8s in the GAT. A friend recently bought a used GAT and immediately stuck TELE 7DJ8s in the unit. After listening to it, told him just for **** and giggles, put the stock tubes in. The 6922s ran rings around the 7DJ8s. Now I'm not saying that's the case in all equipment, but clearly in the GAT the 6922s are a better choice.

[Vhiner]

My experience with a variety of preamps is that tube rush with 6922's is a bit of a crap shoot. I've heard a variety develop "rush" rather quickly. Ironically, I hear it more frequently with the better preamps. High resolution does have its drawbacks. ;-)

[medward0]

My ET3SE burns through CJ 6922s...in less than 300 hours, the tube rush is very, very loud. Occasionally, I get a tube that lasts a bit longer, but I'm really tired of having to replace tubes every few months, the crap shoot whether the tube will be good from the start, and just the general fussiness of it all.

Right now, I'm running an EAT cool valve ECC 88 and it's been blissfully silent for several months now. Amazing how much detail is in the music if the tube is silent....

[Myles B. Astor]

My ET3SE burns through CJ 6922s...in less than 300 hours, the tube rush is very, very loud. Occasionally, I get a tube that lasts a bit longer, but I'm really tired of having to replace tubes every few months, the crap shoot whether the tube will be good from the start, and just the general fussiness of it all.

Right now, I'm running an EAT cool valve ECC 88 and it's been blissfully silent for several months now. Amazing how much detail is in the music if the tube is silent....

I've a pair of the ECC88s here but never tried them. There appears to be though two versions of this tube though.

[plurn]

I have an EAT cool valve ECC88 diamond (newer version with removable cooler) that I got with my ET5 from the previous owner. He had put 100 hours on it and by that time it already had tube rush so he stopped using it. Not great value :(

[lloydelee21]

I have noticed my GAT eats thru 6922s in about a year...playing 2,000 hours a year. That is much faster than my ACT 2 which was probably due to re-tubing around 2+ year mark. I have had a few instances where the tubes went noisy within 6+ months though...i cannot of course say if it was the tube or the GAT...but since i have never had this issue with the suppliers i use in either of my other 2 CJ preamps, i have to think it might be partially the GAT. i use Andy's Vintage, Brent Jessee and most recently Alfred Kaysar/Mullard in Canada. Just my own experience/observations.

[trumpetplayer]

I tried one of the Phillips tubes CJ recommended in my ET3. It went microphonic in under 200 hours

[Vhiner]

This is just my opinion and it is based upon personal experience and observation: I claim no expert qualifications. I could be wrong, but I have developed a point of view.

6922 tubes are notoriously fussy and finding even two from a reputable manufacturer that are immune to "rush" or "microphony" requires numerous tests and usually results in a high rejection rate. I know several tube preamp designers who bemoan this state of affairs but simply accept that, given what we are trying to achieve at the upper levels of audiophilia and the disconnect between tube manufacturers and high end designers, tube problems are increasingly common.

Put another way, few tube manufacturers have a clear and up-to-date picture of what demands modern tube preamplifier and amplifier designers as well as users are placing on vacuum tubes. Tubes are not always designed to meet these demands. I know of one preamplifier/amplifier designer who listens and tests as many as 2 dozen 6922 tubes before finding a set that will perform adequately and reliably in his gear. What is required for tubes to perform well in his gear differs from what is required by other preamplifiers.

One way to completely eliminate this problem would be for manufacturers to produce a variety of tubes designed for specific gear, a solution which is clearly impractical. Another solution would be for designers to compromise sonic performance in order to ensure their equipment plays nicely with the "average" tube. And, finally, one can abandon "unstable" valves for the "solid" state. ;-). For me, the magic of tubes is worth the hassle.

[Puma Cat]

Man, I cannot believe you guys are still discussing this point. When did this thread start, about three years ago?


Guess this is an advantage a CT-5 has; at least it's tube are very durable.

[turntable]

Seems 3 years later I am not the only one with tubes going noisy.

Yes, I still think with the new cj preamps, they are hard on tubes. Never had these issues with my old ART and that had 10 tubes!!

Anyway, I have been using the NOS Telefunken 6922's for 6 months now and I am happy to advise all that no issues whatsoever. Touch wood. The GAT has also never sounded better.

Very happy now.

[Joe Appierto]

Seems 3 years later I am not the only one with tubes going noisy.

Yes, I still think with the new cj preamps, they are hard on tubes. Never had these issues with my old ART and that had 10 tubes!!

Anyway, I have been using the NOS Telefunken 6922's for 6 months now and I am happy to advise all that no issues whatsoever. Touch wood. The GAT has also never sounded better.

Very happy now.

Glad to hear it. Makes you wonder, though, if c-j's newer preamp designs are operating at the edge of the envelope and older, more robust tubes are able to hold up better than current product. I seem to remember another manufacturer (CAT?) whose preamps were notorious for "eating" tubes for that reason.

[Bill Stevenson]

I have an ET5 and have not experienced problems with tube noise. I wonder if your tube problems could be caused by poor voltage regulation from your power company? Perhaps a line conditioner and battery backup would help?

[plurn]

I have an ET5 and have not experienced problems with tube noise. ...

I guess you spoke too soon.


A CCa tube got noisy real quick. I also tried a Telefunken and had the same experience. ...

Sorry to hear it. My ET5 has also burned through a few more tubes since my last post.

[turntable]

I have had my Telefunken 6922's in constant use for almost 18 months.

Touch wood, no more tube failures and GAT has never sounded better

[Joe Appierto]

I have had my Telefunken 6922's in constant use for almost 18 months.

Touch wood, no more tube failures and GAT has never sounded better

Hiya Shane,

Did you ever try the Siemens made/Telefunken branded PCC88/7DJ8 in the GAT. Just curious what your impressions were if you had.

Thanks,

[plurn]

I have had my Telefunken 6922's in constant use for almost 18 months.

Touch wood, no more tube failures and GAT has never sounded better

That is encouraging news. From your previous posts I think it is closer to 13 months though but still good assuming you still put a lot of hours on your GAT.

I average about 50 hours per week on mine so I would be relatively happy if tubes lasted 6 months (1300 hours) based on Conrad Johnson's FAQ of "about 1500 hours before gradual degradation of performance becomes noticeable". Have so far been getting about 300 - 350 hours (less than 2 months) from a variety of tubes - excluding ones that failed within a couple hours.

I scored a mix of 18 nos and lightly used tubes of various brands very cheaply a while ago that I have started burning through. That should keep me going for a while and hopefully there might be some magic ones in that lot that last 6 months.

[plurn]

Hiya Shane,

Did you ever try the Siemens made/Telefunken branded PCC88/7DJ8 in the GAT. Just curious what your impressions were if you had.

Thanks,

not sure if his were Siemens made but he mentioned this:

...

My telefunken PCC88 I have used with the GAT are also superb, however I actually got a little better treble extension from the stk EH 6922's. I should pop them in again to re-listen

cheers

[Joe Appierto]

not sure if his were Siemens made but he mentioned this:

Good catch, thank you. If Shane purchased them from Kevin at Upscale Audio (http://www.upscaleaudio.com/telefunken-pcc88-7dj8/), then they would have been the ones I mentioned. Totally forgot and didn't re-read this thread. :oops-0030:

[turntable]

Hiya Shane,

Did you ever try the Siemens made/Telefunken branded PCC88/7DJ8 in the GAT. Just curious what your impressions were if you had.

Thanks,

Hi Joe

What Plurn said.:D

Yes, I got those first. A bit of a warm cosy sounding tube IMO, at least with the GAT. And yes, got them from Upscale.
One day I will try them again, however not taking the Tele 6922's out anytime soon. Worth the additional cost IMO.

Cheers

[turntable]

That is encouraging news. From your previous posts I think it is closer to 13 months though but still good assuming you still put a lot of hours on your GAT.

I average about 50 hours per week on mine so I would be relatively happy if tubes lasted 6 months (1300 hours) based on Conrad Johnson's FAQ of "about 1500 hours before gradual degradation of performance becomes noticeable". Have so far been getting about 300 - 350 hours (less than 2 months) from a variety of tubes - excluding ones that failed within a couple hours.

I scored a mix of 18 nos and lightly used tubes of various brands very cheaply a while ago that I have started burning through. That should keep me going for a while and hopefully there might be some magic ones in that lot that last 6 months.

Yea, closer to 13 in time I guess - seems longer, but a LOT longer than any other tube.

For the past 6 months they have been on 24/7 probably 6 out of 7 days as I have been using my ss amp, which does sound better left on.

I am kicking myself for not buying at least another pair. Upscale has put the price up and the AU$ has tanked 25%.

[analog brother]

the $ party is over...:tears:

[Bill Stevenson]

I guess you spoke too soon.




Sorry to hear it. My ET5 has also burned through a few more tubes since my last post.

Yea I forgot about that. Using Philips now that cj provided and no problems, though.

[turntable]

Damm!!! spoke to soon.

A couple of weeks ago there was some noise coming from the right channel. It sort of dissappeared but know the right channel is several db louder than the right - and a little more noise.
swapped the tubes over on the GAT, and the slightly louder channel has moved to the left.

These tele tubes are magnificent and looks like I am going to have to buy another couple :tears:

I really wish cj had an easy fix to this problem that did not effect performance to essentially the perfect preamp.

[plurn]

You had an incredible run with those telefunkens. You said "6 months they have been on 24/7 probably 6 out of 7 days" which is over 3700 hours, plus the rest of the 13 or so months.

If you could guarantee that the next set could last that long it wouldn't be such a problem I think. For you they seemed to last more than ten times longer than the electro-harmonix 6922 and are maybe 6 times the price (of upscale audio platinum grade 6922EH). I don't know how much CJ 6922EH go for.

For myself I would be happy with the 6922EH if they lasted longer, so I agree with this "I really wish cj had an easy fix to this problem that did not effect performance to essentially the perfect preamp." and would want it applied to my less perfect ET5 too.

[turntable]

Hi Plurn

When you look at it that way, yes the Teles have easily lasted the longest of any tube on my GAT and sounded the best.. I think they may have actually liked been switch on 24/7 vs being switched off and on every day - I wonder if that is true or my imagination?

The last month I have been using my cj tube amps, so back to more normal usage of 4-5 hours a day and weekends.

I will be looking at buying another 4 - 2 sets from Upscale. Can't really afford them at the moment.

I might put a set of EH6922's back in as its been a while.

The Philips sound interesting?

[turntable]

I think my flu was worse than I realised.

the telefunken 6922's are still going strong!! not sure what was going on, but everything seems fine again.

cheers

[analog brother]

too much scissor paper rock for you and ears were blocked! lol

[Obi]

Hi Turntable,

Noticed you also have a Pass XP-20?

Have been considering the choice of the SS Pass vs the tube CJ. Interested to hear your thoughts on the difference between the two in your system?

Obi

[plurn]

According to a post by Joeinid on another forum, the new GAT series II will use PCC88 tubes.

"Additionally, the tube complement is changed to incorporate PCC88 tubes, of which we have acquired a stock that we are reserving for GAT preamplifiers"

In my mind that could be taken as a kind of recognition/admission by Conrad-Johnson that the GAT is hard on tubes since PCC88 are 7 volt tubes (like 7dj8) rather than 6.3 volt for 6922. That is only in my mind though - they have not admitted anything in reality.

[Coppy]

My GAT was one of the first and after six or eight years is only on it's second or third set of tubes... I don't understand why others seem to be having difficulty with tubes. Maybe we should all resist tapping on tubes to see if they are noisy. Looks like they are upgrading the power supply and audio circuits to increase capacity and sound quality. Tube changes are about a quality supply of tubes providing good sound. So, no conspiracy to report. I'll bet that new NOS tube they are now using is plug and play in your GAT; will sound wonderful and last a good long time.
Happy new year...
Bob

[Rayooo]

My GAT was one of the first and after six or eight years is only on it's second or third set of tubes... I don't understand why others seem to be having difficulty with tubes. Maybe we should all resist tapping on tubes to see if they are noisy. Looks like they are upgrading the power supply and audio circuits to increase capacity and sound quality. Tube changes are about a quality supply of tubes providing good sound. So, no conspiracy to report. I'll bet that new NOS tube they are now using is plug and play in your GAT; will sound wonderful and last a good long time.
Happy new year...
Bob

Same here.. no GAT Tube problems whatsoever.

[Coppy]

Hey Ray,

You know they have just introduced the GAT Series 2 with more teflon caps and an even further beefed up power supply. I think our units can be upgraded. They haven't figured out the cost yet. It also uses seven volt tubes for increased reliability.

Tempting.

Stay warm up there.

Bob

[Rayooo]

I'm having a look into the upgrade. My initial thought was "no way I'm messing with this".. I'm so happy with the system as it's been for the last year or so. It's so nice just enjoying the music when I'm not angling for yet another tweak or "upgrade".

But now... :D, yea assuming it's not too crazy expensive to do, I'll probably do it.

Two feet of snow on the ground and 28 degrees this morning, lovely, just lovely.

[Coppy]

Well... we await the number. Two issues for me; being without my GAT and shipping from Florida. When I lived in Maryland I'd just drive an amp over for repair or upgrade...guess it could be insured for shipping.

[Myles B. Astor]

Well... we await the number. Two issues for me; being without my GAT and shipping from Florida. When I lived in Maryland I'd just drive an amp over for repair or upgrade...guess it could be insured for shipping.

The update will run $4000; the price of the GAT series 2 is now $24,000.

[turntable]

According to a post by Joeinid on another forum, the new GAT series II will use PCC88 tubes.

"Additionally, the tube complement is changed to incorporate PCC88 tubes, of which we have acquired a stock that we are reserving for GAT preamplifiers"

In my mind that could be taken as a kind of recognition/admission by Conrad-Johnson that the GAT is hard on tubes since PCC88 are 7 volt tubes (like 7dj8) rather than 6.3 volt for 6922. That is only in my mind though - they have not admitted anything in reality.

That could very well one of the reasons. I am not sure if the 220/240 volt countries have had the most issues with the GAT being hard on 6922 tubes.

touch wood, my telefunken's are still going strong but one should not have to spend that much $$ ti have a long lasting tube.

Anyone know what the sound quality difference will be from V1 to v2.
Hard to think of any specific sonic weaknesses on the GAT V1.

cheers

[turntable]

Well... we await the number. Two issues for me; being without my GAT and shipping from Florida. When I lived in Maryland I'd just drive an amp over for repair or upgrade...guess it could be insured for shipping.

Boo Hoo. that is not far at all.

I live in Australia :scratch2::no::tears:

[Coppy]

Well... a point well taken. My concern isn't the distance, but the value if the GAT is lost. Insure it and overnight shipping I guess.

[plurn]

Some people are probably sick of this thread, but I thought I should report on my latest experiences. Especially since it seems to be good news for a change.

At the start of this year I purchased 6 x PCC88/7DJ8 tubes to use in my ET5. These are "new old stock" tubes that were purchased untested at very reasonable prices. I am against paying a lot of money for tubes since I have had such bad luck with their longevity in the ET5.

I tested each tube in the ET5 for a very short while to evaluate their sound and to make sure they were not faulty. All were good.

Tubes are:
2 x Matsushita / National 7DJ8 / PCC88
4 x Philips PCC88. I believe this is the same tube that CJ supplies to GAT users now but I did not purchase these from CJ.

All tubes sounded good, I noted the following at the time:

Matsushita - Quiet. I actually hear very faint hiss right near the speaker as low as 1 (lowest volume) on ET5 though it stay very faint up to about 55. Gets more noticeable at 70 right near speaker. No tings changing volume.

Philips - Quiet. Very faint hiss at 81 on ET5 with ears near speaker. Noticeable above 90. No tings changing volume.

With the Philips tubes, the very faint hiss was at different volume levels for each tube. The lowest level that hiss was noticeable was at 68 for one of the tubes which is a very high volume that I never use for listening. So basically they are very quiet tubes. The Matsushita are also very quiet - just slightly noisier than the Philips.

The comment about the "No tings changing volume." is because a lot of "new old stock" tubes make a sound like a bell ting when changing volume on my ET5. The relays clicking when changing volume must really shake the tube around. This is only a problem when changing volume and is not a problem when listening. These Matsushita and Philips tubes do not have this problem.

Over the course of this year I used 1000 hours on one of the Matsushita and it still sounded good by the end of that 1000 hours. I also used 1000 hours on one of the Philips tubes and it still sounded good by the end of that 1000 hours. I noted the following at the end of the 1000 hours on the Philips:
Still sounds good. At ear next to tweeter can hear very slight hiss at 35 and above on left channel, at 1 and above on right channel. But stays pretty quiet even up to 90 on both channels.

I will continue to use both of these tubes - I just picked 1000 hours as a good amount of time*. It is 4 times longer than most tubes have lasted in my ET5. It will be interesting to see how long they last for - hopefully at least 1500 hours or more.

So I am hopeful that these tubes will work around the issue I have been having with short tube life on my ET5. With a sample of only 2 tubes (one of each brand) so far there is no certainty that all these tubes will be good but I am hopeful. While I am happy with both brands of tube, when purchasing more I will just get the Philips as they are quieter (slightly less noise) and the cost is the same.

GAT users wanting to use these Philips tubes can probably buy them from CJ. ET5 and ET3 users would probably need to find another supplier as I believe CJ has written the following in regards to the GAT2 "Additionally, the tube complement is changed to incorporate PCC88 tubes, of which we have acquired a stock that we are reserving for GAT preamplifiers."

So I tentatively recommend the Philips PCC88 tubes for people experiencing short tube life with their recent CJ preamplifiers, if you can obtain them new for a reasonable price. That may change to a full recommendation after a few years if more of these tubes last a relatively long time for me.

Anthony


* Is it sad that my expectations have lowered so much that I think that reaching 1000 hours of tube life is something to be happy about? Other people think small signal tubes should last anywhere from 1500 hours to 10,000. Oh well - regardless of that - 1000 hours is relatively a good long time so I am happy about it for now.

[bILLwOJO]

Wow, those things really eat tubes. They should have had a way to lower the filament voltage down to 6.1V or so. The old Dynaco preamps came with Telefunken tubes from the factory. Yea, I know, not in the same league as A CJ preamp but they ran the filaments a little low and most of these can be found with the original tube compliment still in them. Heck, when I found my crusty MC40 monoblocks they still had most of the original tubes.
CJ should come up with a solution and fix all of these at no charge. A lot of coin for a flawed design.

BillWojo

[Coppy]

Wow, those things really eat tubes. They should have had a way to lower the filament voltage down to 6.1V or so. The old Dynaco preamps came with Telefunken tubes from the factory. Yea, I know, not in the same league as A CJ preamp but they ran the filaments a little low and most of these can be found with the original tube compliment still in them. Heck, when I found my crusty MC40 monoblocks they still had most of the original tubes.
CJ should come up with a solution and fix all of these at no charge. A lot of coin for a flawed design.

BillWojo

So Bill... most of us have no issues with the tubes. Not had any issues with the last three or four of their best Premier models. My GAT has been perfect with a number of different sets for many years. Is your advise to them based on owning c-j equipment or are you just trying to give them advise?

[bILLwOJO]

Don't own any CJ gear, wouldn't mind trying one of there preamps on my Mac tubes though. I'm just surprised if it wasn't just one batch of bad tubes that a company like CJ didn't offer a fix. Running the heaters at that elevated voltage will cause problems with tubes. I'd want to see the heater voltage between 6.1 and 6.2 volt's for long life.
Not bashing CJ gear, like I said, I'd love to try one of the preamps, even an older one, I have heard nothing but good reports on them.

BillWojo

[mfoley3]

Don't own any CJ gear, wouldn't mind trying one of there preamps on my Mac tubes though. I'm just surprised if it wasn't just one batch of bad tubes that a company like CJ didn't offer a fix. Running the heaters at that elevated voltage will cause problems with tubes. I'd want to see the heater voltage between 6.1 and 6.2 volt's for long life. Not bashing CJ gear, like I said, I'd love to try one of the preamps, even an older one, I have heard nothing but good reports on them. BillWojo

I've owned CJ gear for almost 4 decades now and haven't had any problems, other than a couple of aggravating ground loop hums and two tube failures (Premier 16LS2 - 6922 & Premier 11A - 6550). I currently have a GAT pre and ART monoblocks, they have been perfect in all regards. I also have two close friends that are long term CJ users and neither has had problems other than one blown 6550 power tube.

I know nothing about amplifier circuitry and their various operating parameters, so I have no comment regarding heater voltage. However, from my experience, I'd rate CJ gear, overall, as being exceptionally reliable.

[Coppy]

+1

[plurn]

Further to my earlier post http://www.audioaficionado.org/conrad-johnson/11505-gat-et5-hard-tubes-17.html#post802534 I decided to stock up on the Philips PCC88 tubes while they are still relatively cheap at the place I buy them. These should last me a while:

http://sitemedia.loophole.biz/audioaficionado-org/philips-pcc88.jpg

For my current usage of about 2700 hours per year, I estimate these 30 tubes will last at least 16 years in my ET5. Could end up less than that or a lot more then that depending on various factors. Hopefully most of them are as good as the four that I originally purchased.

Does anyone know if these are the same as the one CJ supplies for the GAT? They have factory code DJER.

What follows is probably of no interest to anyone but you never know.

Researching these tubes I have the following information:

- from the factory code DJER, DJ = PCC88. Don't know what ER stands for.
- They are not from CJ or from Upscale Audio. Upscale says the following about their Philips PCC88 which looks the same "This tube has Philips Holland parts, and the associated sound. They were assembled in the Ei factory according to the small etched codes on the glass.". They don't say what the code is.
- Another site worthpoint had very similar looking Philips PCC88 for sale in the past and their ones had factory code "DJER @ 4I". Their description said "Philips PCC88 Produced in Sept. 1964 for Philips by EI (Electronska Industria, Jugoslavia)". My ones just have factory code DJER rather than "DJER @ 4I". Perhaps from the "4I", the 4 indicates 1964, and the "i" indicates september? If that is the case then I suspect something in the "ER" from DJER indicates that they were produced by EI.

So I don't know if that means mine were made by EI or somewhere else. I suspect they were made at EI with Philips Holland parts since all the others seem to be. If they were made in Holland I would think they would say "Made in Holland". That is just a guess.

Anthony

[bgiliberti]

?... If they were made in Holland I would think they would say "Made in Holland". That is just a guess.
What would be your guess if they were counterfeits made in China?

[plurn]

What would be your guess if they were counterfeits made in China?

I don't understand your question/insinuation. Perhaps you can rephrase it? To try and answer it as is, my guess would remain the same, as I would not know they were counterfeit would I. If I did know they were counterfeit, I would not need to guess.

Anyway you seem to be insinuating they are counterfeit. They are not. Really does anyone try and counterfeit low cost relatively unknown PCC88 tubes? They counterfeit well known high priced Bugle Boy and Telefunken 12AX7 and 6922.

The ones I purchased are from a respected long established (operating since 1946) professional supplier in Europe. Who knows - maybe they purchased them direct from Philips in the '60s. The chance of them being counterfeits from China would be near zero. In any case, even if they were counterfeit (they are not) they are quiet, perform well, and last a much longer time than Electro Harmonix 6922 tubes in my ET5 - so what would be the problem there?

Anthony

[bgiliberti]

I don't understand your question/insinuation. Perhaps you can rephrase it? To try and answer it as is, my guess would remain the same, as I would not know they were counterfeit would I. If I did know they were counterfeit, I would not need to guess.

Anyway you seem to be insinuating they are counterfeit. They are not. Really does anyone try and counterfeit low cost relatively unknown PCC88 tubes? They counterfeit well known high priced Bugle Boy and Telefunken 12AX7 and 6922.

The ones I purchased are from a respected long established (operating since 1946) professional supplier in Europe. Who knows - maybe they purchased them direct from Philips in the '60s. The chance of them being counterfeits from China would be near zero. In any case, even if they were counterfeit (they are not) they are quiet, perform well, and last a much longer time than Electro Harmonix 6922 tubes in my ET5 - so what would be the problem there?

Anthony
I'm merely raising a question, not accusing. However, the Chinese (as well as others ) will counterfeit anything that can be profitably counterfeited. It's hard for westerners to appreciate just how low wages are in China; when a country's labor and manufacturing costs are as low as theirs are, there is plenty of money to be made pumping out even the most common tubes, as long as naive audiophiles will pay even a little extra for the bogus NOS label. Are they bad tubes? Not necessarily, and we all know that both the Chinese and the Russians make some fabulous tubes. However, the term NOS at this point strikes me as total joke. Like Phillips and Telefunken did not see the transistor age coming, and kept producing warehouses full of old tubes that audiophiles are now paying a fortune for? Give me a break.

[plurn]

I'm merely raising a question, not accusing. However, the Chinese (as well as others ) will counterfeit anything that can be profitably counterfeited. It's hard for westerners to appreciate just how low wages are in China; when a country's labor and manufacturing costs are as low as theirs are, there is plenty of money to be made pumping out even the most common tubes, as long as naive audiophiles will pay even a little extra for the bogus NOS label. Are they bad tubes? Not necessarily, and we all know that both the Chinese and the Russians make some fabulous tubes. However, the term NOS at this point strikes me as total joke. Like Phillips and Telefunken did not see the transistor age coming, and kept producing warehouses full of old tubes that audiophiles are now paying a fortune for? Give me a break.

From your earlier post, was there any reason you chose to raise this question quoting my post specifically, as opposed to any of the other posts from other people talking about old tubes? From your earlier post it kind of sounded like you found something about the situation I presented that made you think "aha - those might be counterfeit". If that is the case, what was it about my situation that made you think that at the time? I expect I have since allayed your fears about this for my purchases, since I provided more information on the integrity of the supplier in my last post.

Or do you think all claimed "new old stock" tubes from all suppliers are counterfeit (or used)? From your last post, it is not clear but it kind of sounds like that is what you might be getting at when you say "the term NOS at this point strikes me as total joke. Like Phillips and Telefunken did not see the transistor age coming, and kept producing warehouses full of old tubes that audiophiles are now paying a fortune for? Give me a break."

Anthony

[bgiliberti]

From your earlier post, was there any reason you chose to raise this question quoting my post specifically, as opposed to any of the other posts from other people talking about old tubes? From your earlier post it kind of sounded like you found something about the situation I presented that made you think "aha - those might be counterfeit". If that is the case, what was it about my situation that made you think that at the time? I expect I have since allayed your fears about this for my purchases, since I provided more information on the integrity of the supplier in my last post.

Or do you think all claimed "new old stock" tubes from all suppliers are counterfeit (or used)? From your last post, it is not clear but it kind of sounds like that is what you might be getting at when you say "the term NOS at this point strikes me as total joke. Like Phillips and Telefunken did not see the transistor age coming, and kept producing warehouses full of old tubes that audiophiles are now paying a fortune for? Give me a break."

Anthony
Although I responded to your post, I was speaking generally. Also, if you paid a fair price, and the tubes sound great, who cares? I certainly don't think "all" of the NOS tubes are counterfeits or knock-offs, 95% would be more like it. However, if someone who retired from Phillips or Telefunken in 1964 posted that his retirement party was held in a warehouse filled with millions of obsolete tubes, I would lower my estimate to 80%. Have at me NOS valve distributors...:music:

[plurn]

Although I responded to your post, I was speaking generally. Also, if you paid a fair price, and the tubes sound great, who cares? I certainly don't think "all" of the NOS tubes are counterfeits or knock-offs, 95% would be more like it. However, if someone who retired from Phillips or Telefunken in 1964 posted that his retirement party was held in a warehouse filled with millions of obsolete tubes, I would lower my estimate to 80%. Have at me NOS valve distributors...:music:

Thanks for clarifying your point of view.

Anthony

[turntable]

Wow, those things really eat tubes. They should have had a way to lower the filament voltage down to 6.1V or so. The old Dynaco preamps came with Telefunken tubes from the factory. Yea, I know, not in the same league as A CJ preamp but they ran the filaments a little low and most of these can be found with the original tube compliment still in them. Heck, when I found my crusty MC40 monoblocks they still had most of the original tubes.
CJ should come up with a solution and fix all of these at no charge. A lot of coin for a flawed design.

BillWojo

Certainly not a flawed design. One of the best sounding preamps ever made and still is.
The trouble is current 6922 production is shite unfortunately.

I have had my Telefunken tubes for over two years and no further problems and it sounds like a dream.

[microstrip]

Further to my earlier post http://www.audioaficionado.org/conrad-johnson/11505-gat-et5-hard-tubes-17.html#post802534 I decided to stock up on the Philips PCC88 tubes while they are still relatively cheap at the place I buy them. These should last me a while:

http://114.31.201.3/audioaficionado-org/philips-pcc88.jpg

For my current usage of about 2700 hours per year, I estimate these 30 tubes will last at least 16 years in my ET5. Could end up less than that or a lot more then that depending on various factors. Hopefully most of them are as good as the four that I originally purchased.

Does anyone know if these are the same as the one CJ supplies for the GAT? They have factory code DJER.

What follows is probably of no interest to anyone but you never know.

Researching these tubes I have the following information:

- from the factory code DJER, DJ = PCC88. Don't know what ER stands for.
- They are not from CJ or from Upscale Audio. Upscale says the following about their Philips PCC88 which looks the same "This tube has Philips Holland parts, and the associated sound. They were assembled in the Ei factory according to the small etched codes on the glass.". They don't say what the code is.
- Another site worthpoint had very similar looking Philips PCC88 for sale in the past and their ones had factory code "DJER @ 4I". Their description said "Philips PCC88 Produced in Sept. 1964 for Philips by EI (Electronska Industria, Jugoslavia)". My ones just have factory code DJER rather than "DJER @ 4I". Perhaps from the "4I", the 4 indicates 1964, and the "i" indicates september? If that is the case then I suspect something in the "ER" from DJER indicates that they were produced by EI.

So I don't know if that means mine were made by EI or somewhere else. I suspect they were made at EI with Philips Holland parts since all the others seem to be. If they were made in Holland I would think they would say "Made in Holland". That is just a guess.

Anthony

I also bought a large stock of the same type PCC88 Philips with codes DJER 4F and 4G. I have measured about 10 and they are in general low noise and both triodes are matched in gain and DC - an important parameter as the sections work in parallel in my LP275s. From these 10 only one had one noisy triode in the low frequencies - it is now burning-in for a few days, as I have found that some tubes that are initially noisy become silent after 50-100 hours burn-in.

Measuring a few used noisy ECC88/6922 I have found that their triodes were significantly unbalanced. Probably tubes in these conditions will ear out much faster as the tube current does not split equally between the triodes.

[plurn]

I also bought a large stock of the same type PCC88 Philips with codes DJER 4F and 4G. I have measured about 10 and they are in general low noise and both triodes are matched in gain and DC - an important parameter as the sections work in parallel in my LP275s. From these 10 only one had one noisy triode in the low frequencies - it is now burning-in for a few days, as I have found that some tubes that are initially noisy become silent after 50-100 hours burn-in.

Measuring a few used noisy ECC88/6922 I have found that their triodes were significantly unbalanced. Probably tubes in these conditions will ear out much faster as the tube current does not split equally between the triodes.

That is good that they have acceptable measurements and that a good proportion of them are usable. Thanks for reporting the codes. I would think 4F = 1964 June, and 4G = 1964 July.

You have inspired me to check the codes on my tubes more closely. I have found that on some of them, the second row of codes is just barely visible and almost readable with a magnifying glass and a flashlight.

http://sitemedia.loophole.biz/audioaficionado-org/philips-pcc88-code.jpg

Under the DJER row, mine seem to have a row with three characters starting with a partial circle character, followed by 4H. I think the partial circle character must be this one for "Elektronski Industija, Nis, Yugoslavia":

http://sitemedia.loophole.biz/audioaficionado-org/EI-tube-code-symbol.png

I would think the 4H would be 1964 August.

Anthony

[keef]

Rekindling an old thread about ET5 and other CJ preamps. Just ordered another Philips PCC88 from CJ after my Seimans ECC88 6DJ8 became noisey/crackly.

The Seimans actually made it about 2 1/2 years or close to 900 hours or so I estimate. Good sounding and tough tube, sonically more of a front row perspective with a nice top end and great clarity without sounding harsh.

I think the Philips is more balanced top to bottom. Maybe a bit warmer than both the Seimans and EH. The EH doesn’t last any time in my ET5 and it is a shame because I like it better than the Philips.

I noticed CJ now offers the Philips, EH, and Gold Lion now. Anyone had any luck with a hopefully newer batch of EH?

[Puma Cat]

Rekindling an old thread about ET5 and other CJ preamps. Just ordered another Philips PCC88 from CJ after my Seimans ECC88 6DJ8 became noisey/crackly.

The Seimans actually made it about 2 1/2 years or close to 900 hours or so I estimate. Good sounding and tough tube, sonically more of a front row perspective with a nice top end and great clarity without sounding harsh.

I think the Philips is more balanced top to bottom. Maybe a bit warmer than both the Seimans and EH. The EH doesn’t last any time in my ET5 and it is a shame because I like it better than the Philips.

I noticed CJ now offers the Philips, EH, and Gold Lion now. Anyone had any luck with a hopefully newer batch of EH?

Nope. I never liked the EH tubes very much. They always sound somewhat clinical and sterile to me in my LP70S. I much preferred the Ediswan 6922s, but you can't get those anymore, so I'm using Gold Lion, which I also like. My CT-5 required 6N30Ps, and IIiRC, only Sovtek makes those, so I was stuck with that specific tube. I used a mil-spec 6N30P-DR, which was a more durable tube than standard specification.

[keef]

Thanks Puma Cat, I may try Gold Lions in the future. Curious to see how long the Philips last this time around. I also have another 1960’s NOS Seimans ECC88 on the way.

[Puma Cat]

Thanks Puma Cat, I may try Gold Lions in the future. Curious to see how long the Philips last this time around. I also have another 1960’s NOS Seimans ECC88 on the way.

FWIW, I had one of the Philips ECC88s let go on me on the C-J ART150 I had in for review. There was "Pop!" out of the left channel, and then a continual buzz. Jeff sent me some Slovakian tubes to use for the remainder of the review period.

FWIW, I've never had any issues with tubes, either input stage tubes, nor output stage tubes on my LP70S.

Though I've been exclusively using a Constellation Inspiration integrated (:thumbsup:) since the ART amp went back to C-J, so tubes aren't an issue of any kind at the moment.

[Oddiofyl]

I had really good luck with two tubes in my Classic 2SE.... genuine NOS 6h23neb Volkshod Rocket and Gold Lion 6922. Both lasted long and sounded great. JJ 6922 are good if you can get one that is quiet.

I recently pulled the CJ out of service. I'm on the fence about keeping it or my Sonic Frontiers SFL-1 as a back up..

I used some 60's Mazda 6922 for a short time , sounded best but those tubes didn't last very long. The CJs are tough on tubes , but they sound great ......

[jimbones]

Im considering an ET5 or ART 2 Series 2 purchase. Is the tube issue something that should make me lean towards the ART2?? How long do the tubes last.

[Masterlu]

jimbones… Welcome to AA! :wave:

[jimbones]

jimbones… Welcome to AA! :wave:

Lol! Can't do much for what ever its worth but hopefully I can soon post :)

[Puma Cat]

Im considering an ET5 or ART 2 Series 2 purchase. Is the tube issue something that should make me lean towards the ART2?? How long do the tubes last.

I've found they last about 10 years, using the system 2-3 hours a day for say, 4-5 days a week.

[jimbones]

holy crap thats a long time. I only listen 3 times a week

[Puma Cat]

holy crap thats a long time. I only listen 3 times a week

No worries, then! :thumbsup:

[keef]

The ET5 unfortunately eats tubes rather quickly. I haven't had one last more than a couple hundred hours. This includes tubes from CJ - the EH6922 and the Philips EC88. I believe they also offer Gold Lions which I have not tried.

I have also tried 2 NOS Siemens EC88's without much better results. It is a great sounding preamp but can be frustratingly noisy when the tubes begin to crap out. As a result I have had it in and out of my system and even keep the top cover unscrewed for easy access to swap in new tubes.

This has happened to other owners and I believe it has been documented in this and other threads.

[jimbones]

The ET5 unfortunately eats tubes rather quickly. I haven't had one last more than a couple hundred hours. This includes tubes from CJ - the EH6922 and the Philips EC88. I believe they also offer Gold Lions which I have not tried.

I have also tried 2 NOS Siemens EC88's without much better results. It is a great sounding preamp but can be frustratingly noisy when the tubes begin to crap out. As a result I have had it in and out of my system and even keep the top cover unscrewed for easy access to swap in new tubes.

This has happened to other owners and I believe it has been documented in this and other threads.

So I was thinking just getting a stash of Gold Lions after I purchase it and have them on hand to change out when they become noisy

[keef]

That’s basically what I do with the Philips ec88. Think I will try the GL at some point. Happy listening.