The new issue Sovtek 6L6WGC is also coin base. The Tube Amp Doctor site out of Germany says that these are the same as 6P3S-e.

Here is the current issue 6L6WGC
http://www.parts-express.com/Data/De...2-300_HR_0.jpg

http://images.nitrosell.com/product_...GC_Quartet.jpg

Here is the older, military 6P3S-e
http://rutubes.com/published/SC/html...ig&photoID=839

http://classic-tubeware-kunisch.de/P.../6P3S-E-Q2.JPG

I did not want to open that box but...I once had a NU 5U4G that was just sublime. I got another NU and it did not sound the same. Go figure. :scratch2:

Speaking of 80's Tube World has some NOS/NIB British Tungsrams that are very good. I've not seen them anywhere else.

Hmmm...I think I'd stick with the mil spec version which is in short supply and I'd be sure they were thoroughly tested. I need to pull out my remaining pair and give them a go. The thing is that we are using single ended amps and power tubes do sound different v PP circuits.

I just found them at Cryoset for $32.99 a pair. He does do thorough testing. cryoset.com/catalog/product_info.php?cPath=22_80&products_id=334&osCsi d=3cb0dd4a329a5e5e14d28a0a4a64393a

What two tube dealers are saying is that the current Sovtek 6L6WGC *IS* the same tube as the mil-spec 6P3S-e. That the factory in Russia didn't change it at all, except to relabel the tube so that its label would be recognizable to modern tube buyers. I've seen various tube amp owners, both audio and guitar, write the same thing.

The "W" in 6L6WGC designates it as military grade, as opposed to the 6L6GC.

And then there is the Sovtek 6L6WXT+, which I've seen stated is also the 6P3S-e but in a standard base. Again a military grade tube.

I really don't know. The only way to know is to do a head to head comparison. I do know you can't tell what a tube will sound like by looking at it. We make a choice and pay our $$$. I do know that the 6P3S-e was not designed for audio but it works well.

You can go nuts chasing and trying different power tubes for these amps. You nailed it earlier. The driver tube makes a big difference and having a good selection won't break the bank, especially when you don't need matched pairs.

I know a guy who has been in the tube amp business for over 30 years. Has built dozens of tube amps of different types. Restores guitar and audio tube gear.

His favorite tube is the 6L6.

And, a surprise to me, his favorite go-to 6L6 is the Ruby 6L6GC-M-STR. A fairly inexpensive tube. He told me that maybe it is a little tiny bit shy of the best NOS 6L6s, but that it is very close and is a great value. It is made in China and is a copy of the Philips STR-415. The Mesa STR-440 is the same tube. He also likes the above Sovtek 6L6WXT+.

I don't tend to trust these inexpensive, guitar amp tubes. But perhaps I'm wrong. We are in a golden age of tubes and whose to say that Russia or China can't make a very good tube which is inexpensive? Back in the 50s and 60s, a lot of the tubes which are now pricey NOS, were common and inexpensive.

And yes, the 5Y3 and 80 rectifiers are supposedly electrically identical, but Dennis and I found that even though the distortion curves didn't necessarily change much, we were able to notice a significant sonic difference between rectifiers.

Understood. Thanks for the pointers!

The one I like so much is the third link you published (first of the two military tube links) , with exactly the same box printing. I believe they sound great, in my system of course.

Florida Boy: You should get another quad of the 6P3S-E. That appears to be your favorite power tube. The good ones are getting hard to come by.

I know, but there's the question of finding that same quality of the ones you sent me ...

Based on recommendations by Musica Amantem, I have the following in transit to me: 1980s “NOS Matched Pair USSR Reflector 6P3S-E / 6L6GC / 6N3C Military Spec Vacuum Tubes”, from a USA seller who tested the tubes on a calibrated Hickok TV-7 D/U tube tester. More to follow …

The 6L6 is my favorite tube too, at least in my amp. I have the new the Tungsol Big Bottle, GL KT66 and some NOS. The Shuguang KT66z is the variant I like best and keep coming back to. Not cheap but a lot less than the original GEC.

Ruby carefully selects and tests tubes. They are not run of the mill. Try 'em. I have Ruby 6550's and they are a nice tube.

I like 6V6's too. I have a good selection and prefer the Popes. They preceded the 6L6. Same family.

China and Russia used tubes extensively in military applications because tubes don't melt in a nuclear blast. An all tube MIG. :D They never stopped producing tubes. Shuguang is the largest producer in the world.

In present dollars tubes were not cheap in the first Golden Age. A lot of audio folks think todays power tubes are better than old production. I tend to agree.
There are always exceptions.

Please ley us know!

I'm in the beginning stages of trying out the new Genalex KT-66 tubes. Have read mostly positive reviews. More power output than other 6L6 types, draws over 40% more heater current. Have had them in for only 2 hours, but must say they sound quite good. Looking forward to cooking them more and seeing how they settle down. Even right out of the box, there was no harshness to their sound, with a very solid, well defined bass.

Nice big pretty tube too. Looks good on the amp.

Way to go! I hope you are not disappointed. Rig components and room conditions have a say in the end. The description of the tube seems the right one! Yeah, let us know.

They are nice tubes and if they settle in to suit you, well you may be done. The general consensus is that they are better than the originals. I dunno' cause
I'm not willing to pay the price to find out. :D

More dope on the 80: 80 @ The Valve Museum

I'm really liking the Psvane kit, I could have gone full Psvane and ordered their 5u4g, but eh. The "Preferred Series" 5u4g is a great buy, especially since it runs at 2.5a.

This is how it looks with the kit:
http://i.imgur.com/e78V5lf.jpg

I have 4 sets of speakers. Tubes which I like on one set may not be what I like on a different set. Likewise for different preamps.

I'm getting PTSD from this post. It's been top of the tree for month's, as if nothing else on earth existed. I mean I like a nice tube, but jeez.

The EML 5u4 in my 6V6 amp and LP-2 doesn't really cut the mustard. In my opinion at least. I prefer the sophia mesh 274b in my LP-2 for spooky sound staging and the USAF 596 tube in the power amp, that tube in my opinion is end game as far as rectifiers go.... Not willing to shell out for western electric, yet......
That said, the EML works but it just comes up short in comparison, it looks amazing though!

Speaking about input tubes, keep an eye out for Philips/Pope/Adzam (holland) 6sn7gt. Nothing has come close to it in my system, nothing... Watch the auction site sometimes you may find one that slips through the cracks, I paid $50 for mine :)

I got those from Jim Mc Shane a small tube dealer in Chicago many years ago. He tests tubes very thoroughly at real world voltages and culls the ones that don't cut it. Any tube you get from him will be electrically sound. He's not selling these any more because there were too many duds in the lots he was getting. That does not mean there are no good ones left though.

Those CV181's are very nice. I have one in the amp and a UK version in the preamp. :thumbsup:

Were you running a real CV181 or one of the newer fake ones which are 6SN7s in disguise? A good 6SN7 nonetheless.

The 'fake' ones. They are good tubes and surprisingly better than many, but not all, old production in these amps depending on the rest of the chain. They take a LONG time to settle in so patience is required. The 'UK' version, not so long.

Funny that they felt they needed to market a very good 6SN7GT as a CV181, which is not a direct equivalent of a 6SN7. You'd think they might have labeled it as a VT-231 if anything. I don't like it when you can't trust the tube type.

I've settled on the 6SN7 input tube for my amp, as the 6SL7 that came stock, as some others I have, seemed to be slightly less transparent, other things being equal, although the latter provide more gain. Yet, I bet there must be a few 6SL7's out there that may even improve upon some of the not so great 6SN7's.

Between those two, in a triangulation, I believe lies the CV181 in terms of electric characteristics. I wonder if someone can shed some light into the perceived sound tradeoffs involved as a statistical group (i.e., generalize based on hands-on sampling). This may prove interesting because it would narrow down the potential trial-and-error experimentation into a "more likely to succeed" group (one of the 3 involved) ... In fact, I share FloridaBoy's view that input tubes may have a greater impact in the final sound over other alternatives, including rectifiers, especially if one settles the latter on one of the sure winners, like the Sophia Electric 274B mesh plate.

Maybe FloridaBoy or some of our other top tube-rollers?

Note: You can consider those "fake" CV181 alternatives also in this proposed tradeoff summary.

BTW, here's a link on a 7 year-old article reviewing the ubiquitous Shuguang Treasure CV181Z (interesting read): Two drawbacks with this tube are its taxing on the trannies and its price, but the reviewer is fascinated by it! The trannies may loose control of its regulation due to excessive current ... We may want to ask Dennis.

http://www.tnt-audio.com/accessories...s_cv181_e.html

Update: We can safely use the "fake" Shuguang Treasure CV181Z as it has a heater/filament current exactly the same as the 6SN7: 0.6 Amps (600 mA). No wonder it is a 6SN7 in disguise! All other (true) CV181's have a heater/filament current at least 50% higher at between 0.95 and 0.9 mA, seriously taxing the trannies:

forum.audiogon.com/discussions/shuguang-treasure-tubes

https://frank.pocnet.net/other/Servi.../cv3/CV181.pdf

The higher MU (higher gain) 6SL7 draws a heater/filament current 50% less than the 6SN7, at 0.3 Amps or 300 mA:

http://www.radiostation.ru/tubes/6SL7GT-GE.pdf

Thus, a good 6SL7 is healthier for the trannies and allows the latter to better control current in the same circuit topology. What may be good 6SL7's out there which do not reduce transparency (i.e., resolution)? This is one of the three directions in the triangulation cited earlier.

This is a link to a "premium" 6SL7 example, the 5691:

vacuumtubes.com/6sl7.html

My amp came with a 6SN7 as the stock driver tube. I've now tested 8 of them and, to my surprise, the two which I felt sounded the best were two vintage USA Westinghouse brand. Upon some research, I found that Westinghouse ran their own tube manufacturing plants, so these are likely originals.

But they sound great. Can't hear any noise from them at all, I had to toss two of my tubes for being too noisy. Well defined deep bass, clear highs, great vocals. Perhaps if I had a really good 6SN7 the Westinghouses would sound deficient.

I have no plans to try a 6SL7, even though I have 4 of them. Usually these two tubes don't substitute all that well for each other. If a circuit is optimized for one, then they usually don't sound as good with the other.

Dennis sent my KT-88 amp with the 6SL7, although I believe most people use 6SN7 for better sonics. I believe the amp handles both types without problems and the former is less demanding on the trannies and improves their control at half the 6SN7's heater current.

Yours came with a 6SL7? The last 15 or so amps that Dennis has old on eBay have been KT88 with 6SN7. He does switch things up.

Not all, but most of the tubes you see in this picture of the Eniac computer, from 1946, are 6SN7s.

http://explorepahistory.com/kora/fil...h7g3-a_349.jpg

Output Tube Shootout!

Amp: Inspire KT88 SE HO, the one with 20 watt output transformers and which can produce 17 watts with KT88 and 5AR4. Tested with Westinghouse 6SN7GTB and Sylvania 5U4G.

I decided to put many of my output tubes to the test. System setup: Sony SACD player, Parasound D/AC-1100HD, Dynaco PAS-4 preamp (the 1990s version, with 6DJ8 line stage tubes - I'm using Amperex JAN 7308 in it), Focal Aria 906 monitors - efficiency around 88db. This is my small system, it will be a few months until I get my primary set up, as I'm moving. The sound presentation from this system is quite nice, throwing up a reasonably large soundstage, good detail on highs (when there is too much detail it is immediately apparent), a warmish full sound through the mid-bass falling off in the mid-40s, so nothing too deep and as it is a bit warm in the mid-bass it is also immediately apparent when a tube is a bit forward or loose there. My big Von Schweikert towers (now packed in a box) are cleaner and deeper and would be more revealing.

I like tube components in my small, monitor system, as they add to the magic and romance of a simple two-way bookshelf setup.

Music used: Norah Jones and Holly Cole. Simple arrangements with piano, string bass, and brushed cymbals. Very clean recordings.

Tubes being compared: Gold Lion KT88 (new issue), Gold Lion KT66 (new issue), JJ KT77, Sylvania fat boy 6CA7, vintage Tung-sol brown-base 5881, Sylvania 6V6GT, Ken-Rad black glass 6V6GT

The two sets of 6V6 tubes sounded very similar.

Best defined bass: KT66, 2nd place: KT88

Best high freq detail without being too much: KT77, 2nd place KT88, KT66

Best natural vocals: All were pretty good. KT77 maybe best with the KT66 & KT88 just behind. 6V6 was attention-grabbing with its female vocals being a little forward.

Smoothest overall sound: 6CA7 - perhaps a bit too smooth. Bass was a little ill-defined, highs not as tinkling, but a very relaxing presentation. I would say that these along with the 5881s produce the most classic "tubey" sound. Very different than the 6V6, which was more aggressive through the upper midrange.

Tightest sound with best imaging: KT66, 2nd place KT88. The 6V6s threw up a very good soundstage too, but a little looser in the bass.

Hard to say which is the best overall, as all sounded good and all had their strengths. Picking a best might depend upon my mood at the time and the music being used. If I were using my Spica TC60 speakers with their slightly softer highs, I might lean to the 6V6. The 6CA7 and 5881 are very listenable and when relaxing in a dark room, late at night, they would be excellent. Perhaps the best all-around tube with no weaknesses is the KT88, but I wouldn't rank it first in any category. For a dynamic, tight sound, I like the KT66. And for something which is good on definition & dynamics but a bit sexier on vocals, I'd be happy with the KT77.

I can't say there is any tube I tested which I would never use. Two favorites right now are the KT66 & KT88.

Would have loved to have a pair of KT150s to throw in the mix. A little pricey when one isn't sure they would make the main rotation. A nice pair of standard 6L6CG would have been good to compare too. And 6550s. And ... :)

Yep! Tungsol 6SL7

BTW, great tube-rolling work there, pal. Thanks for the very valuable information. I agree on your takes on the 6V6's and KT-88's. I guess having the KT-66 you really won't be needing the 6L6 CG.

You all are tube rolling junkies.:D

I have yet to get through more than the following in terms of rolling and I've had my KT88 HO amp for exactly 1 year -

Power Tubes: GL KT88, RCA BP JAN 807(w/adapter), TS KT120, TS 6L6G(C), GL KT77, TS 6AR6(w/adapter)

Driver: RCA BP 6SN7, RCA BP 6SL7, Syl Chrome Dome(s) 6SL7GT & 6SN7GT, RCA BP VT 229

Rectifier: Mullard 5AR4, RCA 5U4G, Type 80 (w/adapter), RCA 5U4GB

I haven't even gotten to the NOS 6550's, EL34's, 6V6's, & KT66's yet. It will take me years to roll through all the combos I have. I like to listen for a couple of months before I make a change as they all sound so good.(Except the 6AR6, hated them, but think they weren't good tubes)

I will say that I use a sub for anything below 100hz and I think that eliminates an area where most of the power tube rolling is most evident. The differences then are soundstage and HF performance and that is where the drivers show their strengths and weaknesses.

Additionally, I've tried several preamps with the Inspire Amp: McIntosh C46, Bryston BP25, and an LP-27a. The LP-27a is the winner with that amp... and also with a quad of MC30's as well as a pair of monobloc MC240's. I haven't tried it with the Heath UA-2's that I have yet, but I have no doubt it will make them sing. It's an exceptional piece of gear.

I have one more recently acquired preamp that I have yet to try - a McIntosh C100-A. I haven't even set it up yet. I have a feeling the LP-27a will better it, though.

Yup, you can go nuts rolling tubes in these amps. I've had my combo a little more than a year and some power tubes are better than others. It takes listening time to get to know what works best in your rig.

For you LP27a dudes Tube World Express has British Tungsram Type 80 NOS/NIB rectifiers for $25. Very good tubes. Put one in your pre and be done. :thumbsup:

I have so many rectifiers of all types - in 80's I have Globes & ST's from Cunningham, Sylvania, RCA, Philco, GE, etc. I don't think I'll be buying any more - or Power tubes or preamp tubes. Pretty much set for life in tubeland. Actually going to start divesting soon.

Thanks for the tip on Tube World Express and the 80 rectifier. I only have two for my LP27a, a National Union it came with, and a Cunningham from flea bay sold as NOS/NIB. It doesn't look new to me, base is a little loose, not sure if a new tube would have a base that turns slightly.

I sent my 27a back to Dennis to replace the volume pot with a DACT. He recommended another upgrade which I said yes to. I don't know the cost and don't care, this gear sounds so good and is so much fun:

"it makes little engineering sense but … I just completed an LP-27a this afternoon with the stepped DACT attenuator and my wife noticed a change in the sound immediately as I did as well. What the heck ….. I also put in very special silver output coupling caps along with a second filter choke in the regulated power supply. I would recommend you upgrade all the way with these parts as well."

Yeah! and apparently you are a components-rolling junkie!:music:

Some tubes do have a loose base, even if new. But it can very difficult to impossible to tell a used tube from a new tube. Sometimes it doesn't matter much. A small signal tube can last 5,000+ hours. If someone put 200 hours on it, then that doesn't make much difference.

I need one of those ... :sigh: