Solid State Amplifier Advancements In A Decade


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What significant advancements in solid state amplifiers have occurred in the last decade?
Specifically in Class A and Class A/B.

No replies regarding Class D please.
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128x128mitch4t
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.
Bombaywalla, I really enjoy your contributions here, and more often than not agree with them. But, a lot of what you have attributed to happening in the last 10 years has been available for much, much longer than that.
In further defense of Mark Levinson, he's just one of very many, that for what ever reasons lost control of what once was thought be their companies.
I agree with Unsound. That was the basis of my response earlier. I do agree with some of what Bombaywalla wrote. However, in my opinion as an Engineer, much of what he has described has been around for quite some time.

I agree that class D amp design has come quite far, but, we weren't talking about that.

in my opinion, a major technology change will have to happen to supplant the current technology.

Maybe recording, processing and playback based on something other than electricity.

Having designed and worked on circuits, amps, pre-amps, filters, etc. for some time, I can say that good amp/circuit design is just that. There are some very good older designs out there that can definitely stand with the latest and greatest of today. They also managed to squeeze the best out of some not so great components. Sometimes one is limited by the technology of the era.

What I'm finding is that current Japanese transistor technology is also really amazing. That is a step forward.

Look at cars. How long has the internal combustion engine been around? We've greatly improved the efficiency of internal combustion engines, but they are still just that. Controlled explosions turning some machinery. We should be wayyyy past that by now. Don't get me started as to why we aren't.

But, I can tell you that the circuit/amp designers mentioned and many that weren't are absolutely amazing. I still go back and re-read some of Nelson Pass' early papers. Still relevant today. But, if this "hobby" was a popular as automobiles, we would see some major technology breakthroughs. In my opinion.

Look at what happened to phone and computer design/technology. It is changing on an exponential scale.

Who is stepping up to take over for excellent audio designers and move the industry a step or two forward?

I tell you. I count myself as fortunate that I can sit and listen (and still hear) my system/music with a good book, company, and a good glass of wine and appreciate it.

I love it.

enjoy