Paul what is the latest on your amp I heard the Hyper module was not being used any longer, is this true?. Have you looked at doing an amp that carries the PWM to the speaker output much like the NAD M2 did a few years ago. It seems like a perfect mate to the DirectStream
I have thrown the towel in on the PWM output stage for a reference amp. While I think that if we make a smaller integrated or perhaps a smaller amp for a lower cost it'd be fine. In all honesty, it still sounds terrific and most people would absolutely love what it does and sounds like.
But the reference amp has to be of the same caliber as the DS. And that means it's the best in the world, or as close to that as we can achieve. I don't believe it's currently possible to get there with class D PWM technology at this time. Perhaps later. Maybe even Ted will jump in and make it work. Who knows?
But for now we are taking a different course to get where we need to go. I designed a zero feedback, fully balanced input stage that really sounds incredible. It is a state of the art contender as an input stage and may work as a preamp someday. It's also what we'll probably save out of the amp work for a front end.
But the output stage is still up in the air and I've decided to take a different course altogether (than class D). This is the third course correction so far, on this sea of change for the amp, but with a speaker system as resolving as the IRS, a DAC as open and definitive as DirectStream, there can be no choice if perfection is the goal. Perfection IS the goal. Maybe it's just my age, but I don't want to waste time on something that doesn't kick ass on everything else. Not for the Reference design. Not for the main amp in Music Room One. Not for the amp I want to hang our hats on and suggest you do the same.
I am currently listening to a prototype of just such an amp. A few of you have heard this amp when visiting the Music Room. It isn't yet perfect but IMHO there's nothing even close to it that I've heard. It is a design from an old friend, someone I respect greatly and someone who has better design chops than I. Bascom King.
We're going to marry my input stage with his output stage and that SHOULD give us what we want. All MOSFET, high bias Class A/B, housed in a P10 chassis.
Yes it sets things back yet again. But I am not going to be apologetic. I've beaten myself up enough over this already. Our controller and GM have waved enough fingers in my face about the cost of changing directions so many times and now, to hire an outside consultant ...... start over .... abandon most of what we've done ....... welcome to my world of being a perfectionist on a mission. :)