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Cool running, low powered power amp

My regular amp is a Class A, all tube (KT 88’s) affair that runs very warm. For most of the year, it doesn’t matter. But in the dog days of summer, it can become unpleasant in my smallish listening room, where the AC doesn’t reach as well.

My speakers are Volti Razz, which are something like 97 db efficient. My big tube amp is out in California getting repaired, and at the moment, the Volti are enjoying time spent with a Scott 299A. Those 17 wpc are plenty (and sound way better than a 65 year-old amp with original tubes (or at least, tubes marked "H.H. Scott") should. Volti says it only needs to be 8 watts to do the job.

I was thinking of First Watt, or maybe Pass Labs XA 25. But both of those are also Class A. But maybe all Class A are not alike in terms of generating heat. I am not anti-class D, and have had two Class D amps that sounded good, but I’d be more interested in A/B, or cooler running Class A. I'd like to bring it in under $3000, and I am a big fan of used equipment.

Thanks,

David

 

dtorc
fthompson251's avatar
fthompson251
302 posts
 

The wait time on the Coda S5.5 is now up to 4-5 months. I ordered mine March 15 and it's not shipped yet. 

dtorc OP
9 posts
 

Okay - after all of your good thoughts provoked an examination of my priorities with this summer substitute of an amp, I decided to order the Decware Triode amplifier - all 2.3 watts of it. I decided that since I have speakers that can actually make very good use of that kind of amplifier, and I've never owned anything like it, I may as well lean into the whole thing. These are my first and only set of horn speakers, and to not explore the low-power SET experience seems like a waste. I ordered it today, and do not yet know when it will arrive. 

Thanks again for all of your opinions - I valued them all, including exploring ways to goose my AC in this room.

 

David

paradisecom
276 posts
 

The Decware is a fantastic choice.  I was just going to suggest it or maybe a Decware Rachel.  Happy listening and be sure to report back on your findings.

atmasphere's avatar
atmasphere
11,615 posts
 

Class A is always going to run warm. There's no such thing as a 'cooler running Class A.' They would only be cooler by being lower power.

There are class D amps that sound every bit as good as the best class A tube amps now so no need to deal with the heat...

yyzsantabarbara
4,526 posts
 

Class A is always going to run warm. 

Companies like KRELL and Westminster Labs say their amps are Class A and they run cool. The KRELL Duo 175XD that I owned ran cool and sounded like other Class A amps (maybe better). That was up to 175 watts of Class A, when needed. I also own a great Class A amp, the CODA #16 so I have a good frame of reference for the KRELL.

Companies like Gryphon say that the iBias based Class A such as the KRELL are not real Class A. You need to waste electricity for true Class A.

The new KRELL KSA i400 is the next version of what I owned. I expect that to also run cool-ish. That amp is 400 watts Class A at 8 and doubles to 800 and again to 1600. I think it is only 400 watts class A at all impedances.

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