Solid State Amplifier Advancements In A Decade

In terms of sonic improvements; nothing what so ever. I had a Threshold T400 in 1995. It sounded magnificent! I haven't heard anything surpass it yet. Joe

11-03-15: Jafant
Mitch-

I think we all owe a debt of gratitude to Mr. Nelson Pass.
Historically, he has given us audiophiles some of the greatest SS power amps. 2nd would be Mr. Mark Levinson.

11-03-15: Jafant
Second note;

Honorable mention to Bob Carver & John Curl.

I'm sorry Jafant but i think you are very ill-informed. An honorable mention to Bob Carver & John Curl?? Are you kidding? Are you serious?? The Mark Levinson amps that you have been enjoying are all John Curl designs. Mark Levinson was a ditz & just the marketing head of his own company (when he ran it) & it was all John Curl designs that were badged Mark Levinson & sold. Some of those older amps still sound superb today. Not to mention that all Parasound amps & the Halo editions are all John Curl designs.
And, as far as Bob Carver is concerned, you can read up on just how much pioneering work he has done in the power amplifier space. You might not like his amps sonically but that's another matter altogether.

In tube amps while Audio Research's William Z. Johnson did some pioneering work (I've read his 1968 patent that deals with partial cathode coupling) towards tube amp development, significant work in tube amp arena was done by those people who made OTL amps viable & reliable. These are people who started NYAL & Atma-sphere (I don't own any of his amps or preamps) & Futterman.
And, before I tip my hat to Audio Rearch & CJ I'd be tipping it before to people like David Hafler who designed tube amp kits to bring tube amplification to the masses so to say.

I really haven't seen a major technological improvement in circuit design. regulators, power supply, circuit topology, etc. no real major changes. Just better components, layouts, etc. And as I wrote earlier, better transistors.

This is also total BS!
There have been great strides in power supply design esp. in making them less noisy, wider bandwidth & having better line & load regulation (like Kijanki wrote before). Additionally, there are a very few power amps that have a regulated linear power supply. This is a very hard thing to do given that it has to be high current & high bandwidth. AFAIK, this design is patented.
Even tho' transistors have gotten better, if you give better parts into the hands of a mediocre or shitty designer, you are not going to get a better power amplifier.
We've seen better power amplifier topologies materialize such as those that use very little global negative feedback & restrict almost all the feedback to local negative feedback. This one aspect of the design has vastly improved today's power amps sonically compared to yester years. Anyone who does not acknowledge this has his/her head buried in the sand.
We've also seen much better thermal management techniques using both electrical circuits to detect temperature rise & quickly deal with it & physical hardware to wick away the heat generated.
We've also seen power amp designers get a much better understanding of circuit theory w.r.t. what makes a power amp sound better & they have been able to use this better understanding to use higher quality parts where it matters most (rather than using high quality parts everywhere & racking up the cost). So, in this case it's a better execution which can be considered as an advance in power amp technology.
We've seen a significant improvement in power amp reliability i.e. much longer MTBFs esp. for solid-state amps. (given that the user doesn't hook up the power amp in some stupid config & blow it up). Even tube power amps have come a long, long way in this regards. For the most part if a tube amp fails the damage is localized & often can be repaired by the owner.

I agree with much of Bombaywalla's post just above, but I want to make a factual correction: While the earliest designs produced by the Mark Levinson Audio Systems company during the years it was owned by Mr. Levinson were indeed the work of John Curl, subsequently his chief designer was the late Tom Colangelo. Who subsequently followed Mr. Levinson to Cello Ltd., and as far as I know probably also to some of Mark's later companies.

I believe that the ML-1 preamplifier, ca. 1977, marked the transition point between the work of John Curl and Tom Colangelo for Mr. Levinson, with that design borrowing heavily from Mr. Curl's work on earlier Levinson products, but with Mr. Colangelo's work also being reflected in the design, especially in the external power supply.

Also, while the characterization of Mr. Levinson as a "ditz" is perhaps not entirely unfair, my impression is that he does deserve a good deal of credit for many of the important (and ultimately very influential) philosophical concepts which underlied the products of his original company. Namely keeping the signal path as simple as possible, eliminating controls and functionality that would usually do more harm than good, and implementing everything that remained to very high standards.

Regarding amplifier progress in general, though, I can't help but recall the pair of 1950's Marantz 2 monoblock tube amplifiers I owned (and unfortunately sold) during the early 1990's. When operated in triode mode and in conjunction with a benign and efficient speaker load, still among the best sounding amps I have ever heard.

Regards,
-- Al

Almarg,
thanks for your post & factual corrections.
maybe i should have given Mark Levinson some more credit but I lost a lot of respect for him when he lost control of his own company esp. after doing pioneering work in the field. which kind of designer doesn't want to regain control of his company & continue the pioneering work?

Al,
I believe Tom Colangelo and one or two other associates started Viola Labs some years before he died.
It is significant to me that you mention the Marantz 2 amplifiers, (which I never heard), because I often compared the sound of more modern amplifiers in my system, with more up to date circuit topologies with my old Mac 2105, and then realized why they still command silly prices. They just sound really good. When all of the technology and casework is complete, it still comes down to what sounds good to the listener.
That said, I'm using an 8 watt 300b now, but I'll keep the Mac.