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

I have owned tube amps and Class A amps (Plinius, Bedini, Pass Labs, First Watt) but my favorite is my Jeff Rowland Continuum S2 Class D integrated.

I admit I’m more of a green, tree-hugger type, but I’m into audio for great sound and if it took a fire-breathing, Class-A monster to get the sound I love I wouldn’t think twice and would never say a word to anyone else who chose to go that route. That said, I really wish more solid-state, Class-A amp manufacturers would do like Plinius and some Clayton models do and employ a high/low bias switch so it’s possible to leave the amp on 24/7 and not ravage the electric bill or turn the room into a sauna. Seems like such a simple thing to implement, and it comes with the added benefit of not having to constantly turn the amp on and off, which greatly compromises long-term reliability along with the annoyance of having to wait for the amp to reach its optimal operating temperature. Case in point, I recently got my DNA 0.5 amp upgraded by SMcAudio where the on/off switch only operates the power light to let the wife know it’s on when in actuality the amp is always on when it’s plugged in. They do this because they feel strongly that leaving the amp on in a steady state is much better for amp longevity than turning the amp on and off and putting it through the stress of temperature changes, etc. Anyway, I say to each his own, live and let live and so on, but if I did have a power-hungry amp I’d be taking a long, hard look at the new GaN amps from the likes of AtmaSphere, AGD, etc. as we really seem to have turned a ground-breaking corner in both sound-quality potential and efficiency. When Ralph says he’s happy using his new GaN amp over his wonderful OTL tube amps that speaks volumes to me. Anyway…

No AC in the house. Only very quiet ceiling fans and windows that open to the trade winds. So despite my tube gear I really don't expend much electricity overall. As for disturbing neighbors, I don't play my stereo very loud, in any case.

Have you done away with your Class A Amp due to Heat concerns?    No. Because mine don't generate heat.

Will you be moving away from Class A Amp due to Heat concerns?  No. See above.

Will you never buy a Class A Amp due to Heat concerns?  No. Mostly because I'm not going to buy another amp.

Let me state at the outset that I own SS amps. Monoblocs. Actually, SS exclusively along the entire signal path.

A few extraneous thought arose as I read through the thread. I keep my house at 63 - 64 degrees in winter. The room where my amps are is slightly colder because it's over the garage and the thermostat is down the hall.

The majority of responses focused on tube Class A. I'm not going to defend SS Class A or denigrate tube Class A.  You listen to what you like and what pleases you. Many years ago, before I bought my system, I read a lot of arguments about tube versus solid state. In that reading I found a gem of a statement by one of the better well-known designers. I think it was Carver, but I could be way off with that. The statement was, essentially, that solid state amps could be biased to sound like anything... tube included. The bottom line is decide what you like to listen to, then buy the best you can afford. I found what I liked and bought that. I guess they were biased correctly for me.

If you really want to get into the climate change concerns, answer these questions for yourself. What car do you drive? The amp you're running is minuscule compared to a car. For myself, I got rid of my ICE vehicle and will drive 100% EV as soon as it arrives.

Whatever you drive; how many times do you walk instead of drive? I walk a lot (and did so before I got rid of the ICE.) Maybe I'm lucky in that I live in a neighborhood where walking is feasible. It only takes me 30 minutes to walk to the supermarket or hardware store, etc.

What temperature do you keep your house at? As stated, I keep it 63 - 64 in winter. 73 - 74 in summer.  I live in the northeast.  It gets both cold and hot and humid.

To brian61. You really should have differentiated your question between SS and tube amps.

Happy listening.

@atmasphere

Thanks for chiming in. With your selection, it is still more than 5 to 1 in favor of Class A over anything else in this thread.

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.

I’ve been running class A tube amps for over 50 years. I’ve been manufacturing them for nearly that long as well. I’ve never liked the heat, so it was really nice to find that after 5 years of R&D that we had a class D product that sounds better than our tube amps. I run them at home now and don’t miss the tubes at all.

(FWIW Our OTLs have gotten very nice reviews and awards in the high end press, best sound at show, stuff like that.)

What makes an amp sound a certain way is its distortion signature, unless its output impedance is high enough that you run into frequency response colorations as well. Class D amps can have a very low output impedance, eliminating the latter issue and it is possible to have them have similar distortion as tube amps make, meaning they can be smooth through the mids and highs, which is also why people like class A amplifiers in general.

Its very likely that I’m the person @brianh61 is referring to with the comment above.

I went from class A to class D on account of the sound, nothing else. Class A is doomed at this point; ten years from now class A offerings will be vastly reduced and it will be by market forces and not some ’green’ agenda (which isn’t a thing when it comes to amplifier classes of operation- no one is out to regulate that).

So far it's about 5 to 1 that people are not ditching Class A, good to hear. Hopefully we will never see an Energy Star Sticker on the back of Amps :)

@kingharold funny. 

@kingharold +1

Mike

I have a class A amp on my main system and a EL34 tube integrated on a second.  The heat is a non-issue for me. I've owned some good quality class D amps (2 different Bel Cantos and a VTV Hypex along with some more basic units) and like the sound quality of my current amps better. The only advantage I find for class D is that they can be left on all the time, but I really don't expend that much energy in pushing the on/off switch. 

I have no intention of getting rid of the two class A stereo amps I use in my triamplified DIY fully horn loaded system because of the anthropogenic global warming scam.

I have to say that over the period I have running my Class A mono amps, coupled with my tubed preamp, I have been loving my music again. There is a sweet spot with these mono Class A amps that allows listening with no fatigue, glare or otherwise unwelcome issues or noise. I would characterize them as "warm" sounding so it depends on what you prefer.  My units have a stanby mode so the "Heat" is only an issue when in use, but they do run Hot! I have also installed some micro fans which are very silent to move air from behind the units which helps.

Overall the most musical combination I have owned and enjoyed!

I enjoy warm and full sound out of class A solid or SET tube amp.

Thus I am happy to live in Pacific Northwest Washington State.

It is not that hot during summer.

It is good to have extra heater during winter.😀

Also the cost of electricity is the most affordable in WA.

Thus I may live in Washington State for my life.

Thomas

Living in Florida it's a double hit to the electricity bill. First the cost of running it, then the cost of running the AC to cool the room. I'll keep my Benchmark AHB2.

They’re in my some of my active speakers - and they’re excellent, especially in winter.

It’s considered a feature in northern Minnesota.

I have a Pass Labs class A amp and yes it does get warm but never felt any heat issues from the amp. I live in the northwest where summers can get hot here and we don’t have AC. Still not a problem. I went from a class A/B tube amp to this amp and am very pleased with the upgrade.

So even an audio forum can’t get away from political comments. 

I own & really enjoy the best/ worst of both worlds. Full class A, 100 watts / side tube integrated amp. Rogers High Fidelity EFH 200 Mark II. Sounds great; very powerful, dynamic, detailed w/ full frequency extensions but as airy, beautifully toned as I could ever want. It should at its price & does & should do so for a long time. 
 

That said, it puts out some serious heat all the time. Living in New England, I don’t mind 8 or 9 months of the year. For myself, very much worth the trade offs.

You'll have to pry my Pass XA 30.5 out of my cold dead hands. I live in New England and this time of year I'm grateful for the heating bonus to go along with the spectacular sound.

Living in the area where the temperasture is around 95 F for at least 3 month of the year. Have p.single ended tube A class amp and preamp and do not switch on the amps at all during the summer. Than again, hi fi is a winter sport, plenty of other interesting stuff to do during the summer...would I change for some other kind of amp? If I find some that gives the same illusion of live music (like tubes do) yes, but so far ss or hybrid did not delivered it. Have not heard any ganfet amps, curious about it...

I purposely avoided Class A because of the heat and chose high bias Class A / AB amp as a compromise. I enjoy the sound and anticipate a longer service cycle out of them (electrical charge was not the concern). I was also aware of class D technology is on the rise but did not have a full confidence as I had with the high bias class A/AB amp.

I love the sound of a big ass, power sucking, space heater, street light dimming Class A amps…Glorious! 

Pass XA25 owner.  I am inconsistent concerning leaving it on or off.  Last month my energy bill was for 300KWh.  The amp gets to 120F at most.  I like it, I won't get rid of it.

@retrocrownfan Your ps200 amps are not Class A, they run squarely in class AB or B.

I don't have air conditioning.  I had to abandon (at least in the summer time) my 400W class a amp for a 180W class A amp.  (I'm talking watts of heat, nothing to di with watts per channel which is close to single digits).

Jerry

No heat concerns here. My pair of 1980s Crown PS/200 amps benefit from a really good chassis design that keeps them very cool without a need for any fans. Actually cold when playing music not even close to being hot at idle.

I have been using tube gear for several years now and will never give them up. However, I recently borrowed a FirstWatt F6 from a friend. After I listened to it for a few hours I made an offer and now it is mine. I just ordered a pair of Tekton Double Image speakers to pair with it. The purity and accuracy of its sound won me over. Now I have an outstanding set of tube gear and what I perceive to be an equally amazing Class A amp. I will keep it, heat and inefficiency be damned. 

Someone mentioned space heater, as much as I loved my Threshold amp, that's exactly what it felt like. Very happy with a Mcintosh now, crazy low energy usage and sounds almost as good as a class A or tube amp. Running 24/7 so that's important to me. If I only listened a few hours a day I'd probably choose differently though....low power SET for my Omega 95db bookshelfs.   

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.

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.

I like that heat source. It was 10° here a few days ago

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.

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. 

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.

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.

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.

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.  

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.

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 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.

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.

Class A up North, class D down South. No brainer.

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.

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.  

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.

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

Cheers. 

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...

@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.