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

Hi Ralph, what happened with your prototypes? Any closer to your class Ds?

Yes. We've continued working on the design, hammering out details. Recently that's turned to the power supplies, since the entire thing has to be protected against shorted speaker loads and the like.

I hear good things about the Element, Purify and a few others.

@daveyf If heat really is the deal (and installing inexpensive venting is out of the question), then you might consider a class D amp, as they run the coolest of any kind of amp. There are some class D amps now that rival tubes for smoothness and detail. However one thing about class D (and nearly all solid state amps for that matter) is that you have to have enough power that you never clip the amp. Tubes are different in that they can have such a graceful overload character that you don't know that the amp is clipping- hence the myth that tube power is somehow more powerful than solid state power. But its a myth; its just that they overload differently.

Remember Ralph, hot glass looks just like cold glass. This is from personal experience (goes for metal as well).

True, but this comment (taken out of context) was part of an explanation of how in most cases the filaments are not why tubes run so hot- the 6C33 being an exception.

Tubes have to heat their filament to be operational. That is their principle of operation.

It is, but that is not why tube amps run hot. I explained that earlier.

My dedicated room is a stand alone structure on a concrete slab. No basement.

'Stand alone'? Like an outbuilding of some sort? If yes, installing a ceiling vent would be easy and inexpensive. If you already have an amp you like, this really is the easiest (and cheapest) solution, and its not noisy.

punch a small hole in the wall and put the amps in the next room.

@daveyf  This isn't a bad suggestion. We have a number of customers that have their amps installed in the basement beneath their listening room, near the ceiling so the speaker cables can be kept short. Of course our amps have balanced inputs so its easy to run long interconnect cables to make that possible. But you could do the same thing if you got some decent line transformers (so as to convert from single ended to balanced and back again at the amplifier) so you could run the long interconnect cables.

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.

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...).