Summer tubes and winter tubes.

[Briz Vegaas]

Does anyone swap tubes to suit the weather.

I have KT120 in my CJ LP70s. vs the stock tubes
- they are bigger
- they seem to run warmer
- we get hot Southern Hemisphere summers
- heat is bad for electronics longevity
- overall I preferred the KT120 sound, but a bit of variety is good to.

So, I am contemplating running the stock tubes in summer ( only). Does anyone else do this? I have heard of folks using solid state in summer. Why not a cooler running tube.

Note. - I run the KT 120s topless ( no cage), open to the sides, back( largely) and front, 2 cm free space under the amp ( on cones) and with the recommended 10 cm gap above.....just. But there are other components on the shelf above the amp.

It's fine in winter. This will be my first summer with a tube amp. 30 degrees Celsius is typical here, we can get high 30s on occasion and it can be a humid heat, although that varies. On paper a summer tube choice makes sense.

[rlw3]

I noticed when i went back and forth between 6550s and kt 120s in both the pr 12 and lp 275 that the kt120s caused the bias pots to be adjusted lower. Does that mean less heat? With my hand over the tubes I thought the kt120s ran cooler.How would you measure this accurately?
When ac is bad, giving less quality i use my lesser tubes and do not use vinyl.
I have emails going back in forth with cj regarding the twin hums (tranny and speaker) from the lp 275 which goes up after 3-4 hrs of play. My concern is that the hums are due to tranny heat which will not go away when clean power resumes when air conditioners are no longer used.
The response from cj so far is that bad ac might be responsible and that usage over 3-4 hours might be the problem with no other comments as if this is acceptable for an amp in this price range. My previous email to them asking about tefloned amp break in resulted in a 300 hrs is good enough message. Both responses are completely inadequate and unworthy of this great company

[Briz Vegaas]

Yes, go to the Naim forum if you want an idea about good service from a hifi company.

I had a fuse blow on a power supply . I had a reply from Naim in minutes when I posted a question. Naim has site administrators monitoring the posts who jump in with advice. they even allow discussion on non Naim gear, but not on mods which is fair enough. I would have preferred it if I didn't have to leave the DAC on 24/7 but its true that it performs at a higher level and the fuses no longer blow. It's a brilliant DAC, particularly with the XPS DR power supply. Not cheap but you get what you pay for.

On the tube front I seem to recall that the stock tubes ran surprisingly cool on the LP70. I will need to experiment a little to see if this was not some other factor at play.

[GaryProtein]

Briz, I think you're confused.

It's summer TIRES and winter TIRES!

:laughin: :lmao: :roflmao:

WAAAAAY too much time on your hands!

[Coppy]

Ray, I think you're confused.

It's summer TIRES and winter TIRES!

:laughin: :lmao: :roflmao:

WAAAAAY too much time on your hands!

+1

[Briz Vegaas]

yeah, but this is a hifi forum, not Top Gear. The fact is if you are reading this you have some time on your hands, that's kind of the point of a hobby.

Heat management is an entirely legitimate discussion topic. Go find another bridge to dwell under Mr Troll.

I assume you either have solid state amps or air conditioning. I have AC, it's called opening a window and letting the fresh air in.

[Still-One]

With my hand over the tubes I thought the kt120s ran cooler.How would you measure this accurately?

You can try one of these. They work great.

You will find a bunch at Amazon.

http://ecx.images-amazon.com/images/I/41w8EIJglFL._SX385_.jpg

[GaryProtein]

yeah, but this is a hifi forum, not Top Gear. The fact is if you are reading this you have some time on your hands, that's kind of the point of a hobby.

Heat management is an entirely legitimate discussion topic. Go find another bridge to dwell under Mr Troll.

I assume you either have solid state amps or air conditioning. I have AC, it's called opening a window and letting the fresh air in.

We need to lighten up and not take things quite so seriously. I was just making a joke. I don't blame you for reaching for the gold ring.

[GaryProtein]

You can try one of these. They work great.

You will find a bunch at Amazon.

http://ecx.images-amazon.com/images/I/41w8EIJglFL._SX385_.jpg

Even with an IR thermometer, it would be hard to measure the temperature accurately. You would have to know what percentage of the measurement was the glass envelope temperature and what was the filament temperature.

The emissivity of the glass envelope seems to be questionable when using an IR thermometer to measure its temperature unless you could select the type of surface you were measuring in the IR thermometer's menu.

[Briz Vegaas]

It's a bit like blind listening tests, if you have to use tech or a special process to tell the difference then the difference isn't that big.

I just got the impression that the stock tubes ran surprisingly cool when i first got the amp. Cooler to the touch than my old CA200. Given that the LP70 case work is full of holes on top this could have been very deceptive. I guess I was expecting a little furnace given the comments from friends that own tube amps.

The other night I noticed how hot the space above the amp was and the volume on the CT 5 was only at 30 to 33, I wasn't pushing it hard.

PS. The smilie helps if the dig is jovial. :-)

[Masterlu]

It's a bit like blind listening tests, if you have to use tech or a special process to tell the difference then the difference isn't that big.

I just got the impression that the stock tubes ran surprisingly cool when i first got the amp. Cooler to the touch than my old CA200. Given that the LP70 case work is full of holes on top this could have been very deceptive. I guess I was expecting a little furnace given the comments from friends that own tube amps.

The other night I noticed how hot the space above the amp was and the volume on the CT 5 was only at 30 to 33, I wasn't pushing it hard.

PS. The smilie helps if the dig is jovial. :-)

Don't mind Gary... he even changes his dental floss in the winter. :D

[rlw3]

You can try one of these. They work great.

You will find a bunch at Amazon.

http://ecx.images-amazon.com/images/I/41w8EIJglFL._SX385_.jpg

thanks Jim, is technique on how-distance, angle when you point it critical?

[rlw3]

It's a bit like blind listening tests, if you have to use tech or a special process to tell the difference then the difference isn't that big.

I just got the impression that the stock tubes ran surprisingly cool when i first got the amp. Cooler to the touch than my old CA200. Given that the LP70 case work is full of holes on top this could have been very deceptive. I guess I was expecting a little furnace given the comments from friends that own tube amps.

The other night I noticed how hot the space above the amp was and the volume on the CT 5 was only at 30 to 33, I wasn't pushing it hard.

PS. The smilie helps if the dig is jovial. :-)

Does anyone know if or how much amp heat temp increases when playing music for an hour vs having it idle with no music? Would preamp gain or lack thereof make a difference when no music way being played? I need a tube amps for dummies book.

[GaryProtein]

Why are you more interested in the heat than the sound? You were selective enough to purchase a special tube amplifier. Some people tube roll and get tubes by other manufacturers to get what they think is a better sound with the same model tube. Why do you want to risk significantly changing the sound which will likely happen by changing the tubes?

Don't you think the designers selected the particular tubes for the sound they produce and designed the rest of the circuitry to work best with those tubes? Changing the tubes to different models could adversely affect the stability and longevity of the rest of the circuitry.

Heat management of the room comes with the territory when you purchase either tubes (or class A solid state for that matter).

You should get an air conditioner if the heat really concerns you.

[audiot servant]

Briz,

Would a ceiling fan help? Would have thought a relatively gentle speed would also probably be quieter than reverse cycle. Certainly about 300 times more energy efficient as well as keeping the noise floor down a bit.

Graham

[rlw3]

Why are you more interested in the heat than the sound? You were selective enough to purchase a special tube amplifier. Some people tube roll and get tubes by other manufacturers to get what they think is a better sound with the same model tube. Why do you want to risk significantly changing the sound which will likely happen by changing the tubes?

Don't you think the designers selected the particular tubes for the sound they produce and designed the rest of the circuitry to work best with those tubes? Changing the tubes to different models could adversely affect the stability and longevity of the rest of the circuitry.

Heat management of the room comes with the territory when you purchase either tubes (or class A solid state for that matter).

You should get an air conditioner if the heat really concerns you.
I am suffering from tranny hum after afew hours of play that may be heat related. That is why i am concerned obout heat. I really really don't need you to tell me to get an air conditioner.

[Briz Vegaas]

For me it's more about wanting to understand how my choices affect the longevity. Of course sound is important, that's why you buy a high end system. If a tweak is going to be detrimental, even if thats a few years down the track, you want to know the likely consequences so you can make an informed decision.

I read Paul Hynes comment recently that he designs his power supplies to run cool so they last longer. If I have spent $15k on amplification making it last also has to be a priority.

When summer rolls around I will be trying out the original tubes to see if it makes a difference and to see how I feel about the sound. We are forecast to get 32 degrees C this week, thats 90F and its the second week of spring. So begins my first "summer" with a tube power amp.

[rlw3]

Briz,
What country are you from? Is it 120 or 240 volt? I wonder if the 120/240 difference effects heat and performance. What parts are different in 240 volt gear?

[GaryProtein]

I am suffering from tranny hum after afew hours of play that may be heat related. That is why i am concerned obout heat. I really really don't need you to tell me to get an air conditioner.

If you have a physically humming transformer after a few hours of play time, you should take it up with the manufacturer. It sounds like you may have a defective unit.

One would think they design a unit to be useable in a variety of climates throughout the world. They don't make equatorial, temperate and arctic models.

[pstrisik]

For helping to keep the amps cool, I use a pair (for monoblocs) of quiet USB powered fans from Coolerguys.com -- Your Computer and Home Theater Cooling Source for Over 10 Years (http://www.coolerguys.com). You can get 80mm, 92mm, 120mm, powered by USB, A/C, with or without speed controls or temperature sensors.

I went simple and got a pair of 80mm USB fans that I plug into an iPhone type charger block and into a switched outlet on my power center:
Coolerguys Dual 80x25mm USB Fans with Grills (http://www.coolerguys.com/840556090557.html)

They are rated at 22db both running and I can only hear them from three feet. Not at all from listening position with system muted.

Doesn't do anything for the temp in the room, but certainly helps keep the amps from running too hot, particularly with a shelf above.

I have the fans velcro'd to the shelves above and gently blowing over the tubes.


http://img593.imageshack.us/img593/8009/ovja.jpg (http://img593.imageshack.us/i/ovja.jpg/) http://img825.imageshack.us/img825/1930/5g6a.jpg (http://img825.imageshack.us/i/5g6a.jpg/)

[rlw3]

If you have a physically humming transformer after a few hours of play time, you should take it up with the manufacturer. It sounds like you may have a defective unit.

One would think they design a unit to be useable in a variety of climates throughout the world. They don't make equatorial, temperate and arctic models.

If you would read my first post on this thread to Briz, I have contacted cj. since both monos act in the same fashion it is either bad ac or bad design which will not be fixable. ps tube rolling is desirable due to tonal differences and the fact that gear makers use highly available tubes, not always the best.

[Coppy]

If you would read my first post on this thread to Briz, I have contacted cj. since both monos act in the same fashion it is either bad ac or bad design which will not be fixable. ps tube rolling is desirable due to tonal differences and the fact that gear makers use highly available tubes, not always the best.

Ray,

If the problem was a design issue we'd all have it and would be hearing from many folks. They design around the tubes they use so it can be argued, that are the best for their amps. So, probably the power. I understand that variations in the normal values of voltage and frequency can cause the troubles you describe. How loud is the hum? Can you get a power regenerator to try?

Good luck,
Bob

[rlw3]

Ray,

If the problem was a design issue we'd all have it and would be hearing from many folks. They design around the tubes they use so it can be argued, that are the best for their amps. So, probably the power. I understand that variations in the normal values of voltage and frequency can cause the troubles you describe. How loud is the hum? Can you get a power regenerator to try?

Good luck,
Bob

Bob, the loudness goes from very very low, to moderate, to high enough to hear at the listening position. I have heard it go up and dwn a little during the same evening. Usually it is higher in early to mid pm. Hopefully it will greatly reduce in cooler weather. My pr 12 was dead silent so I was spoiled. Contacted cj and the said it might be bad ac or it might be usage after 4 hrs with no mention that it should go back to cj for repair. Waiting for fall weather. Ps did the same with both 6550 or chryo kt120s. Hum from speakers and trannys is always identical. When bias lights go on this is identical also. One bad amp I would understand. With both acting the same I have great hopes it is the common denominator the ac. I live very close to a military base and wonder what that does for ac

[Bugs762]

If you want to know which tubes run hotter. Set up your amp and let it run until the tube temperature stabilizes. Pick a point near the amp and set up your thermometer. Take for or five readings over an hour (the more reading the more accurate) and average them. Do exactly the same setup with the other set of tubes and average. The hottest tubes will have the hottest temperature on average.

Bugs

[Briz Vegaas]

Still running the Kt120. It's getting hot at midday (31) but humidity is still low and I'm mostly listening at night at present. Let's see how I feel when summer proper comes.

[microstrip]

I am suffering from tranny hum after afew hours of play that may be heat related. That is why i am concerned obout heat. I really really don't need you to tell me to get an air conditioner.

I had exactly the same problem with one of my cj LP275s - it showed only after 4-6 hours and then stayed permanently. It could be heard at the listening place ~10 feet away. I tried using a lower voltage mains supply in my PSAudio P10 power regenerator and it did not solve the problem.

However when I removed the transformer cage the hum reduced a lot. Releasing the transformer mounting screws also helped to the point I can not listen to the hum at distances larger than two feet. I am considering ordering some new shock absorber mounts to mount the transformer and the cage, but as the hum is not affecting me any more I have been postponing it.

[AudioNut]

This is my idea of a very nice summer tube . . . and doubles nicely as a winter tube too when called upon to do so. . . . . :D


http://cdn.zmescience.com/wp-content/uploads/2010/09/power_transistor.jpg

[Briz Vegaas]

Over rated.

Is that out of an iPod? Looks like something out of last years iPod nano.

You have to ask yourself..... Is it cryogenic ? Is it hard to get. Is it made by a nice Russian or Chinese lady in a forgotten sweetshop. Does some japanese guy on a mountain bless it before storing it for 20 years in a bears armpit. If no, then how can it be any good?

You tranny guys make me laugh, but you always seem so jolly. I guess you have to be good natured to put up with that harsh sound. :-)