Are there any tube amps that don't give off any---

No

Sorry, there are no Class D tube amps. It's glass audio PLUS HEAT or silicone junctions and less heat.

Yep all those tube amps are accentuating  Climate Change ..LOL!

David Berning is known for his high efficiency, long tube life, low heat tube designs.

Less expensive models/designs are offered by Linear Tube Audio.

The current David Berning branded line is more upscale/expensive.

I'd ask them if they have any heat measurements they would care to share.

DeKay

+1.  Contact LTA.

No reviews yet, but the amp you seek is the Entropic Anti from Unicorn Audio. It uses tubes hand made in Utopia from pure unobtainium alloy imported from Krypton.  

The tubes our amps utilize are called, "thermionic" because their cathodes must be heated, to emit electrons.             Thus far; no one’s developed another method, regarding vacuum amplification/rectification (except, perhaps, Unicorn Audio).

If you use a higher efficiency speaker you can generally use a lower powered amp.  In addition, some designs use less power and put off less heat.

LTAs run relatively cool.  The other amps that run cooler are the current Bob Carver amps. Neither are cold but both run dramatically cooler than traditional tube amps.   

I see MC is up and Atom.. That's planet "Uranus", runs VERY cool, but a slight, "outhouse" smell as the day goes on..:-)

NOW

I don't know what your winters are like, but I swap my tube amps out in the summer for class Ds. I use Valve amps in the late fall, winter and spring (cool summer nights if we have any). It keeps the house quit toasty, when I really get going.. I use a Mac preamps, C20-C2500s, all valves.

Have the best of both worlds.. No idea on your speakers, and the actual room size. 

Mac has a hybrid. Valve pre section, and SS amp section. They run pretty cool. They will provide you with running temps too. They always have good data, just have to know where to find it.. 

Personally a valve pre amp with Valve/SS power amps, nothing better.
Next in line for the money, a GOOD integrated, tube pre/SS amp section.

I wonder if anyone is making an Integrated with a tube (valve) pre amp and Class Ds for the power amp? I'm sure they are out there. Easy enough to do it with separates.

The valve in the preamp can get hot to, 6SN7s get hot, a lot of preamps use them now too..Carys, and Freya +, I love them, but they run HOT...

Regards

Why not just vent the heat out of the room? A ceiling vent isn't expensive to install and some dryer duct hose will send it out of the house with the help of an inexpensive low speed fan. Then air conditioning won't have any trouble keeping up; you may not even need it.


But here's the thing. Most tube amps get docked about heat due to the filaments of the tubes. Literally the only tube where this is a thing is the 6C33; with any octal-based power tubes the heat contributed by the filament is inconsequential. So that means most of the heat is coming from the class of operation, and will be about the same amount as a solid state amp running the same class of operation and making the same power. I know this because our amps make about as much heat as any for their power, but if in Standby (no B+ on the power tubes) you can have the amps on all day and walk up to them and grab a power tube and hang on. They just aren't that hot.


The only way I can think of to get away from that is a class D amplifier. So if that's out of the question, then do vents in the ceiling. It will cost a few hundred dollars but you can have the fan operated by a wall switch and no impact from the heat of the amps in your room as long as the vents are above the amps (heat rises, after all...).

NO NO!!

@atmasphere Actually my AC works well enough to cool the room, BUT the issue is that it is a little noisy, just as any fan vent would be.
Like you stated, my tube amps also run coolish when they are in standby, but once the voltage is applied, up goes the heat expansion. My amps only use two KT150’s per side, so in the big picture, they do NOT give off a huge amount of heat, but they give off enough to really make my very small room nice and toasty within about an hour. My ss amp does the same thing, after about an hour and a half; but here’s the thing, it would be great if a tube amp existed that gave off no real heat after multiple hours...maybe this isn’t realistic, given the technology, but is this possible??

No.

But trust me on this one- I've seen it- a fan is a **LOT** quieter than an air conditioner! You can hardly tell its on, yet the installation I saw kept the room cool despite a pair of class A triode OTLs with 42 power tubes per channel making over 500 watts. Yet the fan was a whisper.

SS output and tube input sections.

Hybrid amps can be fairly cool.

But, a 10-15watt per channel integrated tube amp, is still going to put out a good ~100 watts of heat.

LTA is a good rec but also smaller low powered amps won't heat the room overly much. My amps been playing for about an hour just held my hand over it and its barely warm. That's a 17 watt pushpull amp, a SET amp would also likely be cooler. How much power do you need?

bottom line, any tube power amp with any meaningful power output will have output tubes that will provide a decent amount of heat

flea watt amps still produce heat - 2x 300b’s or 211’s or 845’s or el84s - of course then it is just a matter of degree, one person’s ’minimal and acceptable’ is another’s ’too much’...

hybrid amps might be the answer... really only low level signal tubes produce what most folks would consider insignificant amounts of heat

Do like many do a very good SS amp like high quality amplifier
and a Vacuum tube preamplifier a great combination of punch and dynamics, and still get some tube soundstaging and layering.

You can also buy high quality vacuum tube digital as an option 
pleanty of options if you have the $$. You didnot stste your budget 
or how much power you need to drive your speakers.

I have an LTA Z10. It puts off less heat than even some class D amps I’ve had. Very cool running for a tube amp and for almost any amp. 

Al Gore says there is no relationship between tube amps and climate change :).  

mine when it is in the off position

Looks like LTA would be a good choice. However, I would like to recommend you to consider looking for those amps using small power tube like EL84. Manley Stingray (20 watts), E.A.R. V12 (50 watts), Luxman SQ-N150 (10 watts). 

Yes to David Berning.

daveyf,

Check out this amp.  It has tubes to give you that tube sound, but they’re not the output tubes.  Much less heat!

https://www.psaudio.com/bhk-signature-250-amplifier/

they have a 300 watt amp also.

All the best

JD

Carver 275

I just got my PS Audio Stellar M1200s amp. They are hybrid design class D with tube input. They are barely warm after hours of playing. In fact they are designed to be stacked up because they emit little heat. The sound is awesome by the way.

Linear Tube Audio (David Berning’s) designs. Very low heat and long tube life.

Depending on your amp design, you may be able to run them with smaller tubes like EL34B/6L6GTB/KT66/77. Bias at the lower end of their range should cut heat easily in half. Might even sound better.

Highly recommend Quadrature Z mono blocks by David Berning.  I had mine for many years and they ran very cool, even with long hours of operation in the summer.  Previously I used Lamm M1.1 mono blocks also for many years. They were hot by comparison especially in warmer weather.  Z's are not cheap. 

I have a Carver Crimson 275. The tubes become warm to touch, but not hot. Same with power supply and output transformers, warm not hot.  Sounds great too!

Warm but not hot is how my amps get now. Problem is, that due to such a small room, warm over time is enough to heat the room considerably. 
I like the idea of maybe rolling in some smaller tubes, which might lead to even less heat. Something I will look into.

Bob Carver

Your body temp is typically 98.6 F. That’s equivalent to a pretty darn hot summer’s day. What’s the answer? Additionallly, humans, cows, squirrels, goats, chipmunks, wolves, fox, dogs, cats zebras, elephants all have flatulence....., Getting back to original question, no....

Benchmark AHB2 class A/B power amp (2x200W@4ohm) runs very cool (SMPS, modulated power supply rails).  It was designed to sound neutral/accurate, so perhaps you can use tube pre, if you like warm sound.

https://benchmarkmedia.com/products/benchmark-ahb2-power-amplifier?variant=585555021

I would embrace the heat and sit in my underwear with a martini

Musical Fidelity has amplifiers with Nu-Vista tubes. From what I understand they were being developed as a new tube technology but was shelved due to the invention of the transistor. 
I mention these because they look nothing like a traditional tube so do they produce the same heat or any?
Does anyone have knowledge of these tubes they could share?

Why not replace the current vacuum tubes with LED tubes?

@rushfan71 The Musical Fidelity NuVista 600 and 800 are hybrid amps that have a tube preamp stage and use bi-polar transistors in the output stage.  For these units to sound really good, they need 20-30 minutes of warmup time.  

We had a client actually return a wonderful vintage tube amp because he thought it gave off too much heat.  He was already aware that tube amps give off heat, but it was apparently more than he expected.  Worth noting that this was just a little 7189 stereo integrated.  The client was worried he would touch a hot tube accidentally, even though they are at the rear of the unit.  

If you are concerned about heat.  A tube amp is not the right choice.  

Some custom made class A high end amps are water cooled with very low heat factor.  For tube amps I never see it. One of the purposes of glass popping out tubes is heat Exhausting so heating is actually in tubes nature. 

Maybe become a nudist?

Heat is work and work is heat. 

Heat rises. I use a small silent fan above my tubes that sucks up and does not blow down. 

In winter tubes will help and in summer they will not so there’s a bit of equilibrium. 

Seriously a ceiling fan may be the solution for you.  

Yes-

As others have mentioned - Carver Crimson 275 -

https://www.bobcarvercorp.com/copy-of-crimson-raven

@austinstereo.  That is interesting. I am not concerned about the issue of injury, as I never let folk get near the tubes. Your client has a point though if he had little children or pets that could get injured!
The issue I brought up in my OP, has to do with the fact that the room size is also crucial. The smaller the room, the bigger the problem.
Some folks probably don't comprehend why this would be a problem, as they enjoy a large enough listening  room that a warm/hot amp ( heat wise) won't ever be an issue. 

You could consider a class D amp with a tube input buffer. The Purifi modules add very little of their own sound signature, but require a front-end driver board to provide some gain and impedance matching. There are a couple of companies that make amps using these modules (which are very efficient) that use a triode-based front end.

https://vtvamplifier.com/product/vtv-amplifier-stereo-purifi-audio-1et400a-amplifier-with-vtv-vacuum...

ATM makes an Korg NuTube based input buffer. I assume they make a complete amp that uses this buffer, but I don't know the model. The ATM buffer seems a bit pricey for what it is, but it might sound good. 

https://atm-audio.com/product/buffer-korg-nutube-for-hypex-nc500-and-purifi-audio-1et400-v2/

I haven't heard either of these, but have heard an amp using the Purifi module and it is very clean and detailed.

@jaytor Isn't the Purifi module a Class D module? I'm not really interested in a Class D amp, mainly due to the fact that all of the Class D amps i have heard are too sterile sounding to my ears. Even the 'best of class' Jeff Rowland models.

@daveyf  The amount of heat generated by a particular amplifier is predictable to a close approximation based on its current draw.  All of the current drawn by an amplifier is either converted to sound, which is subsequently converted to heat, or else it is lost immediately to radiant heat.  This is a consequence of the 1st and 2nd laws of thermodynamics.   There is a small amount of energy (either as sound or as heat) that escapes the room, so the amount of heat retained in a room is somewhat less than the amount of current the amplifier draws. 

This holds regardless of whether you are talking about tube or solid state.  It is just the laws of physics.  Any energy introduced into the room that is not lost through the walls will be retained in that room and sooner or later be converted to heat. 

 If you want to solve the problem without relying on AC to remove heat, the best bet (especially if you want class A amps) is to build a system around high efficiency speakers.  These usually can be driven by amplifiers that draw relatively little current even though they are class A.  The other alternative is to use a Class AB amp, which will draw less current when the music doesn't require it. 

As for me, I just put in a really nice quiet two stage AC system in my listening room, which had formerly been so hot I couldn't use my favorite amps during the summer months.  My new AC cost 6K, which was a pittance compared to my investment in audio.   It is a high efficiency system that will pay for itself easily over its lifetime.

Yes, the Purifi module is class D and I agree that class D amps can sound too sterile. I had an NCore based class-D amp previously and that is how I would describe it.

However, the sound signature of amps based on the newer modules (particularly the Purifi) are going to depend more on the input driver design than the class D module. The Purifi module has vanishingly low noise and distortion, but limited gain (as well as low input impedance), so a front-end driver is required in most situations.

I believe (although I haven't personally heard) that the right input driver can create a sonic signature that is pretty similar to whatever you're looking for. I could be wrong, but I'm giving this a try myself by building a set of DIY monoblocks using the Purifi module so that I can experiment with different buffer/drivers. I'm planning to build (or buy) a few different options to see what works best in my system, including building a triode-based buffer. 

The VTV amp I linked to above uses a triode buffer that looks interesting, but I think I'm going to design and build my own. 

I think VTV has a pretty liberal return policy, so if it seemed like it might work for you, you could give it a try.

+1 LTA Berning designed OTL.
I have the MicroZOTL headphone amp.
SS detail with tube musicality and not hot.