How far have ss amps really come in the last twenty years?


I have owned and enjoyed my Jeff Rowland model 8 ( recently modded and upgraded by Jeff to the last version) for many years. I recently had the opportunity of comparing it ( after mods) to a few of the current ss models from Gamut, D'Agostino, YBA, Parasound, Sim audio, CH precision, Constellation,PS audio,Pass Labs  and Musical Fidelity. The results were very interesting, because to my ears and in the systems that we did the comparison, the Rowland held its own against all but the most expensive D'Ag and CH amps. Even those were only very slightly outclassing the Rowland in the areas of top end resolution...and a tad in the bottom end resolution. Now the thing is that the last revision to the Rowland 8 was designed by Jeff over ten years ago! 
So, my question for those more technically inclined than myself is...how far has the design of ss amps come in the last ten...or even twenty years? 
128x128daveyf
There's three different aspects to this question: design, implementation, and results. From a design point of view there may be nothing better since the Distributed Node Amplifier. I don't know, it just seems that way.

In terms of how the exact details of how that or any other design is implemented, well that is a whole other story. Because as stringreen and others notice its not just the design but the parts that go into them. Then on top of that you have to factor in the way those parts are used. Not only where in a circuit but the physical circuit itself. People over time just get better at shielding, the physical location of a circuit, vibration control, all the little details. No doubt this has gotten better. 

And then, results. What I think you're asking- how much better do they sound today? To which I would ask: Do they?


There's another aspect that comes into play which I think is perhaps the biggest advance - price for performance on an inflation-adjusted basis you get way more today.
Are saying most all expensive amps made in the last 20 years sound similar?

Very hard to believe!

Do they all have the same flavor?

Or do you have no preference of one over another?

If so, there is no best or better or worse.
On paper the best possible circuits have already been designed, now it's just a matter of implementation and personal preference.
How far have ss amps really come in the last twenty years?

Quite a bit, just to pick one area, global feedback was used too much to get distortion down 20 or more years ago, these days the good ones do it without too much feedback, and with the use sometimes of just local feedback, but that takes a bit more matching ect to do right but the rewards are exponential.

Cheers George