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

@mrdecibel : I have never been in a rock band and my hearing is still good! Right in front of me to my left is a Richard Brown Electronics Lab BEL 1001 amp (serial no. 0001). A favorite of Harry Pearson's from 1980. This requires an IEC cord - for which I bought a $99 Pangea from Audio Advisor. My TOTL Toshiba DVD player (2003) needs the same. So there, at least two pieces using IEC outlets!

I will put that BEL 1001 amp (first production one!) up against any of today's pricey gear! For too long audiophiles have been conned into the belief "spend more, get more"! So a $10K amp has to be sonically much better than a $1K amp? And a $50K amp better than the $10K amp? Not necessarily true! With electronic gear diminishing returns sets in quite quickly! 

roberjerman, I obviously have been mistaken, so I apologize. So you do believe, good amplifiers, sound different from one another, and that some, such as your Bel, sound superior. Great, we are getting somewhere. And, you purchased a Pangea cord, and, did not return it. Another great ! See, was that so hard. BTW, the MK V was a great version of your amp; the original you have, good potential, and would sound good with my pair of AR3a, giving them some zip in the high end, and lots of control in the low end. The Bel I owned, for about a year ( version 3 I believe ), drove a pair of Janis W1s for a while, which I replaced with an Electron Kinetics Eagle 2A, and sold the Bel. A good amp, yes, but lost out big to my Krell KSA 50, which to my ears, was in another league. When I sold the Bel, I had no regrets, and still don't. Enjoy ! MrD.

If you want to hear an amplifier sound "different" get a tube amp with an output impedance of several ohms! Ohm's Law rules here! A frequency response that will follow the varying impedance of the typical speaker.

There is far more to it than that!

Distortion plays a major role in the sound of any amplifier due to how the ear/brain system treats distortion, which is to say it treats it as a tonality. We've known this fact since the 1930s (see Radioton Designer's Handbook, 3rd edition).


Most solid state amps are designed to have minimal distortion and is why so many of them sound the same, which is to say, harsh and bright especially at higher volume levels. Now tube amps actually make more distortion, but because they have lower ordered harmonics in greater percentage quantities than solid state, the ear's masking principle allows the lower orders to mask the presence of the higher orders. This is why they sound smoother. The odd bit is that the presence of the 2nd or 3rd harmonic (both of which are treated the same by the human ear) causes a greater sense of detail and soundstage definition! This is why tubes are generally more detailed and have more depth.

Now if we could eliminate distortion entirely that would be great. But we can't, so it appears that an injection of a 2nd or 3rd harmonic is beneficial to solid state designs. This is recognized by several prominent solid state designers in high end (John Curl and Nelson Pass come to mind) and it should be no surprise that they have turned out some of the more highly lauded solid state amps as a result.


It is this bit of understanding about how the human ear works that is one thing that's changed in the last 20 years and it is perhaps the most significant- parts and topology notwithstanding. Its our ability to take advantage of how the ear works through engineering that yields the most progress. We're only just now starting to crack that nut.

I am sorry, but neither Pass nor Curl can compete at the top level. Perhaps they are doing something wrong.