Tubes/SS Power Amps?

We've been looking at class D for 9 years now. We have certainly thought about it.

The preamps we make now would work fine with any Class D amp.

The concerns we have had are: is class D a threat to our tube technology? Answer, yes, although not with any current embodiments. However Class D is the rising star in amplifier technology and if its still early on the price/performance curves it may yield something yet.

Second, should we be building one? Answer, maybe. It could well be poor marketing on our part to not have a class D amp in our lineup, as we have been focused on getting as close to sounding like real music as possible. So far that has been easier with tubes, but I am pragmatic enough to know that that could change!

Before I became an "audiophile", as opposed to someone who just listened to music, I was an electronics technician, and my belief was, "If you can't measure it, you can't hear it, and the best specifications sound the best". After I got into the "high end", I discovered I could hear many things that can not be measured. At the same time I discovered that what sounds best "theoretically", actually sounds the best for real. Theoretically, class A tubes sound the best, and most audiophiles will agree on that.

Atmasphere, could you compare Class D, with Class A tubes theoretically?

Orpheus10, why in your opinion do Class A tube amps "theoretically" sound better than Class A solid state amps? Do tubes measure better than solid state devices?

Based on observations/listening experiences to date, I'm finding good Class D seems to sound more like good tube amps I have heard than most other SS amp technology. Plus they have the ability to drive many difficult load speakers out there today that tube amps are more challenged to do, without great cost, expense, size and heat.

Based on listening alone, I find my Class D amps, Bel Canto ref1000m monoblocks, hard to fault in any real way. But on paper, the very highest frequencies that might be heard are the area where Class D historically may not be up to snuff with the very best amps otherwise. That technical bottleneck as I understand it is due mostly to switching frequency limit and effects on associated low pass filtering needed. The latest Class D amp modules I read about seem to indicate that switching frequency continues to increase and improve as the needed technology improves. That would seem to push what is possible even higher.

Practically, I think Class D has arrived not just as being viable but the most practical approach to high performance amp design. Technically, the frontier is still moving with Class D technology it would seem, much as it is still with computers and related digital technologies.

The sky is probably the limit down the road, to the extent that it matters practically. Practically, what it means is though performance will continue to go up, becoming even more practical for even the most demanding applications, even more importantly, cost/prices will continue to go down as top performing Class D technology becomes more mainstream for high end audio applications.

Outside of high end audio, where Class D appears to already have a firm foothold, Class D seems to have already clearly arrived and is starting to take over.

Mapman, transistors switch on and off, as opposed to always on as is the case of Class A tubes. AB amps have two halves of a cycle that match. "Audibly", these three can sound so close to the same when the best parts are used, that "most" people can't tell the difference.

In motion pictures, what in reality is many still frames becomes a "moving picture". This analogy of still frames is good for transistors, digital, and switching amps, which is why extreme audiophiles preferred class A tubes. While none of us can detect still frames at a movie, "some" audiophiles seem to be able to tell the difference between switching and non switching amps.

It's for certain I can not instantly tell the difference when comparing "high quality" amps with different designs; but for me, I've found it to be cost effective to follow in the footsteps of "extreme audiophiles" who can; and that's where the critical decision making process comes in.