I wish my ears were more forgiving. I think I could make some Class D work for my ears with tube line stages and dacs, but, i really don't want to deal with the confoundedness/pestilence/mainteance crap with tubes anymore...
@deep_333 @inna I get the whole thing about dealing with tubes. Imagine what that looks like when you are a provider of tube equipment! Now comes the tricky bit: imagine that as a manufacturer, if you produced a class D amp after 45 years of class A tube products, that if you make a substandard amp you will damage your market because people will think you've gone nuts, can't hear what you're doing, cashed in, stuff like that. Add to that the simple fact that every OTL manufacturer that ever moved from their OTL mainstays to solid state promptly went out of business.
So you can see we didn't go into this blindly. We knew the class D R&D would be a bust if it didn't sound every bit as good or better than our OTLs (which, in the tube world, rule the roost when it comes to transparency and bandwidth...).
As I've pointed out on numerous occasions, the sound of class D amps varies from worst to best over a wider range than tube amps and for that matter conventional solid state. What this means in plain English is if you've heard one, there's no way you've heard them all. Some are grossly incompetent IMO, some are soso, some are excellent. Most are somewhere in between.
So I've no surprise when someone says class D isn't for them. The truth of the matter is if they heard the right amp they likely wouldn't say that, but they have no way of knowing.
No-one will remember this class D in twenty years, and no- one really needs it except a few fashionistas. But we do need a completely new amplification device to be invented, both tubes and transistors virtually exhausted their potential. This is one more commercial BS, this class D, similar to another cd reissue, slightly better or slightly worse than the previous one.
Inna, I think you are mistaken about this. Class D has a longer history then it appears you know of from this post. It dates back to the 1950s and the first home applications were sold in the 1960s. Sony and Yamaha made class D amps in the 1980s. Like any technology its evolved. No-one takes germanium transistors seriously in this age but they were de rigor for solid state amps in the 1960s; only the very advanced designs used silicon. These days silicon has gone the way in favor of MOSFETs and IGBTs.
The big change that seemed to really push class D amps was the advent of self-oscillating circuits, which appeared about 20-25 years ago. This allowed for more reliable, stable and simple designs.
Tubes have not seen much evolution in the last 40 years by comparison. The big advances in the tube world have come from improved materials for construction (better capacitors and resistors for example) and not to put too much of a point on it, but innovations from designers. I'm one of those designers having several patents in the OTL world; another is David Berning with his excellent zero hysteresis radio frequency coupling system (usually called 'ZOTL' a meaningless acronym created by Harvey Rosenburg; they are not OTLs...) and perhaps Jack Elliano, who to my knowledge is the only one to push SETs further, with his patented class A3 technology and Ultra Path design.
I realize I'm not going to convince you of anything- listening is the only way to do that! But there is something you'll want to know: Over time, class D has been making inroads into the musical instrument market (bass and guitar amps). The first ones I saw, as in high end audio, were hard to take seriously. But that's changed. Guitar and bass players alike appreciate the reduction of weight while at the same time being able to get their 'sound' about which they are surprisingly picky- not unlike audiophiles. As class D invades that market, tubes will get pushed out. The musical instrument market is the bread and butter of tube producers. It appears that market will look very different in 10 years. So class D is something that has to be confronted and figured out. Whether that's already been done is a different story 😉
