Ditching Class A Amps due to Heat - Sort of a Poll

A discussion elsewhere about the future of Class A made me wonder how true one statement really is. So the questions are...

Have you done away with your Class A Amp due to Heat concerns?

Will you be moving away from Class A Amp due to Heat concerns?

Will you never buy a Class A Amp due to Heat concerns?

I only have a class A/B unit that does Class A up to 6 watts with almost no heat so really can't speak for those who have used in the past or currently own and run Class A Amps.


Amps that sound great will always have a following, whether they run hot or are ridiculously inefficient.   

I like tubes but if I didn’t own tubes I would definitely look at a low powered Class A amp.   

Years ago I borrowed a Pass Aleph.   It ran so hot the heat sinks took on a blueish purple color over the years.  It was ugly and ran hot as hell but it sounded great. 

Myself not a fan of the space heaters. Regardless of how great they sound. Keep in mind what the heat means: wasted electricity / inefficient designs. I do now recently own 2 carver tube amps but they don't kick out much heat. Some but not bad. Primaluna tube pre has minimal heat. 

Come summer though I'll buy another Class D something as it's hot AF where I live. 

With the newer GaN and Purify amps and with future improvements surely coming down the road I’d have to think long and hard about buying a traditional SS Class A amp.  But at least some Class A amps from Plinius and Clayton have a hi/low bias switch so when not listening critically you don’t have to heat the house or assault the electric bill.  Nice to have viable alternatives. 

I tried and ended up moving the GaN and a Purfi amp to a secondary system and one to my daughter's condo. Just not for me, maybe one day. 

I actually have a Heed Elixir in my office that runs cooler than the NAD-M10 I had in my office. Must be the Transcap technology these Hungarians are using in their Class A amplification. 


NAD's hybrid tech is one of the most innovative amp techs I've seen in recent years.  It runs hotter than Class becayse it has a small Class A in between the Class D.  Very cool stuff and it sounds pretty good too.

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The car I drive around town is 100% electric, up-spec'd home solar system...so for me class A isn't a problem. Thank goodness because I presently have five different class A amps in residence.

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Somehow Biden is involved in Class A discussions. Yeah he's the first thing I think of when amp shopping. 

My mind goes to how much of a draw this purchase will damage the account total. 

 Also, the wife and her talks, complaining, whining. 
she is a nagger. 

@ghasley do not get those batteries wet in your car. Also, I have a fried with solar in his home and he is still battling noisy power in his system when on battery power?? 

I never have to worry about losing power due to being on the same grid as H2O plant and emergency service in my town.  Infrastructure in America is weak at best especially the power grids. Texas and CA are the worst! 


Wots damatta? Is everyone around here overliteral?

Personally, I abhor wasting energy. Everybody else can "waste" whatever they want to.

@erik_squires I did not find the sound coming out of that M-10 as good! That was the unit I sold. 

I love my Pass class A amps.  Yeah they're hot, but the sound is magic to my ears.

I used to keep them on all the time.  Nowadays, I turn them on about an hour before listening sessions, saves on my electric bill and heat generation.

@jwei +1 that’s pretty much the routine. I also keep my basement at 63 degrees so I don’t heat it in the winter unnecessarily and whatever the heat generated by the Pass XA30.8 amp doesn’t bring the temperature up that much. 
In the summer the basement is cool so it’s rarely a problem.

I have the Pass XA60.8 mono blocks on my list of amps to try.  

24 hrs for my monos to be their best sounding. 

such a difference from initial power up to same time next day listening. 




do not get those batteries wet in your car

Its inadvisable to submerge any car, gas or electric.


I have a fried with solar in his home and he is still battling noisy power in his system when on battery power

Your friend obviously has site/product quality/design specific issues. My system isn't designed to take us off the grid in the event of nuclear war, ours is designed to supply the grid with a similar (in our case a little excess) amount of generated power that we consume. We spec'd our system to eventually supply three electric cars as well as potential max usage for a 4,000+ sq ft home. 

Thanks for all the answers so far, the consensus with this small sampling is still what I expected, more thumbs up than down.

In full disclosure, this discussion came up within one where Luxman stopped making Class A amps due to Environmental Issues. A big defender of Class D claims that Class A is going away on it’s own and would never become effected by limits placed on electrical consumption or heat output, but just because everyone no longer wants it or wants Class D or similar.

So the one political comment above is not off base, just the person pointed to because he just does what he is told.


Keep ’em coming

@brianh61   :So the one political comment above is not off base, just the person pointed to because he just does what he is told.




you have won the internet, and the best comment in this forum. 
-buys Brian a cold Guinness pint!

The amount of people that own Class A stereos is so minuscule they don't have any impact. Most folks I know listen to Alexa for music or own a soundbar for TV. I'm the only odd ball that owns a stereo.

Do as your conscience and pocketbook tell you. In any case, as I mention in another thread, when my hot-running Class A Mytek Brooklyn Bridge bit the dust I replaced it with a cool-running Cambridge CXN. Not quite as wonderful-sounding but still a pleasure to listen to.

Well, I just have to say this to our friends in DC about my Class A amps. 


Texas officials unveil a revision to the Gonzales flag in light of the  recent power outtages : r/funny

Get real. Climate change is everyone's problem. 

@hilde45  You're going to have to get rid of those tube amps if you want to start preaching climate change.

Class A amps are way too small in number to have any impact on climate.

+1 jerryg123

I switched from tubes because of heat, weight and power tube replacement cost.  Started out experimenting with a few SS amps and ended up with AGD Audions.  Could not be happier.  Still have tubes in my signal path as I running through a Cary SLP05.  Over all very happy!!

I'm open minded to the latest technology,  I would like to try a GaN amp to see what they sound like.    It wouldn't displace my current amp , it would be for a second system in another room that in all honesty would get more use 

Air conditioned house and hot running Audio Research CL60 finally got to be too much for my wife, and me. Went to a tube/mosfet hybrid, Moscode 600 Maxi, but... went back to a VT100. But now I'm thinking GaNFET.

Worth a try.

Answers to your 3 questions. No, no and no. I love my Audio Mirror tube monos. Also have a ss A/B Van Alstine amp. 

@jerryg123  - I understood.  I was merely saying the NAD hybrid amps are pretty technically interesting.

FTR - Never wowed by Class A.

I use an A/B amp right now, and was a lot happier with Class D from IcePower than any Pass I've ever heard. 😂

My point is not to bash Pass, honestly, but that you should buy amps based on sound quality, not technology.

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NO! That would be stupid! Heat is inherent in the design/class A....and people should have known that prior to buying. Also, huge exaggerations about how much heat is produced. Will you stop using your oven? Jeez....lastly....If I AM paying MY electric bill, who the he** cares what amp I’m running? Aye yi yi...


@erik_squires Yep had an old Bel Canto that was Ice Powered I think it sounded better than that NAD.


I have a Sugden A21 Signature and yes, it gets warm but not super hot. It cools down rather quickly. I did my research before purchasing it and knew that class A amps get warm. I don't have any problems with that at all.

Well one thing for everyone  not to forget is  science.  If the science is right about global warming  the science  is also right about nuclear  winter. So thank the lord for the Ohio  class submarines  anytime the world is in danger the Ohio s are there for our safety with a push of a button the global warming is over.  

Living in northern Europe in a north facing room, Class A heat is not a problem - perfectly acceptable in the Summer and eminently usable as space heating in the Winter.

I'd prefer not to have the power consumption. But - regrettably in that regard - all of the amplifiers that meet my criteria for sound quality have been tubed or class A solid state.

I was looking at a Luxman L-590 and probably should have bought it. I keep hearing scuttlebutt that they are moving to class A/B only. Maybe I’ll start looking at a L550 AXll.

I have class A mono’s and never give the heat output a second or even a first thought. It is what it is and who cares. It is nice for everyone to have option to buy what they like.

There may be two ways to think about this… you love your speakers so stick with the amp that brings out their best… or….


You are committed to class d so you find the speakers that brings out their best.

Either way you are trying to optimize the amp, speaker, room combination to deliver the sound you are searching for. I suspect that most of us are going to try many combinations… and keep trying them because that is part of the fun.

I have 2 systems in my house, both Sugden ClassA . Will never own anything but. The upper system are the Sugden MPA-4 mono blocks, and the basement is the IA-4 integrated amp. Both systems have the amps on top so they can dissipate the heat. With a fluke meter and amp clamp, each mono block pulls 3 amps of power when turned on.  Rated output is 165 WPC Pure class A Bliss.

In the winter Class A is great.  Like one guy said, the total volume, Pun intended, does not add up to much. A flight across the state in a jet, or buying an Amp from "Jyna" is more of a sin.  Be "Amurcian" be Class A. Buy a Coda 11.5 Class A .   If you want, if not, there are many great sounding cool Amps, Pun intended, amps.  


My 4 Class A monoblocks use about 1/2 kW total, which heats the room nicely for most of the year, for less than a dollar a day. Not ideally green, perhaps, but then I don't drive a pickup truck or commute 30 miles either.

Almost all push/pull class A amps are really very rich class A bias AB amps. For example the Pass 30 watt class A amps are 30 watts class A but they are reall75 watt AB amps. Look at the Stereophile tests. And things get worse as load impedance drops. About the only amps you can be sure are always class A are single ended amps which are class A due to topology and are almost always low power anyway. Then again these amps still run hot.

Perhaps the only push/pull amp that may really be called class A was the old Levison ML2 mono blocks. They were 25 watts/8 ohms, 50 watts/4 ohms and 100 watts/2 ohms and class A all the way down to 2 ohms.

While I'm all for Climate Change and have the Asthma lungs to prove that it's (I grew up in a Steeltown). My setup is kind of an Oxymoron (?). BATVK50-SE with 8 6H30 tubes and she gets very hot not long after it's turned on. The BA Preamp feeds a pair of Orchard Audio Ultra Amplifier modules which in turn are powered by a 1500VAC, 20A Torroidal.

Sounds amazing so yeah. Tubes feeding solid state is the way to go I guess.

I own a Luxman 590AXII class A and would have a hard time going back to Class D, although I have owned Class D and G before and I liked them very much. I'd go with Tubes, but don't want the hassle and then I'd get into tube rolling and that expense. I don't mind the heat at all. Odd to me that it's a big issue. 

And yeah, cut out the stupid political comments, go over to Twitter if you want that BS. 

hmm... I dunno, I'm no "class" expert, but the Marantz Ruby is some type of class D and sure sounds nice to me and to the various critics I've read.  The Technics SU-R 1000 is None Of The Above, and it is supposedly hella great.

I'm not married to any "class"... there is no one class that universally sounds great or bad.  It's all in the execution.  

another possible compromise if you gotta have at least some "class A" in your life is the Arcam amps... A first x watts, then switch over to B (?) after that.

Have you done away with your Class A Amp due to Heat concerns?    NO

Will you be moving away from Class A Amp due to Heat concerns?  NO

Will you never buy a Class A Amp due to Heat concerns?  NO


Since the early 1990s I have run Krell KRS200s uprated by Krell to 400W per side.  They are probably about the hottest amps around and can pull down nearly 2kW per side.  Sound is wonderful of course.  It's a big room and in the basement so it doesn't get too hot.  I don't heat it in the winter as it's dedicated just to music.

As for the global warming lobby, it can go swing a cat.  In the recent COP-OUT 22 all the big countries of the world were unable to agree any positive action.  We are all too greedy and competitive.  They never agree any ACTION, they just make promises they do nothing to keep.  1.5C is already gone, measurements show we've already reached it.  Don't worry, humanity will adapt, it always has done.  Sure some will be inconvenienced, some will die.  It's always been that way.  Anyone wanting action on global warming needs to pray for a meteor hit.

To your question - yes, I moved from Class A amps (MSB) to Class A/B with Pilium and very happy with the change. Pilium amps run cold and sonically they are superior as to my taste. It is a kind of a rare occasion when you can enhance pleasure in an environmentally friendly manner.