20 year old solid state technology.....

I would tend to agree with the latter.

Open up a 20YO SS amp and one built today and you're not going to see much in the way of differences ihn any of the major parts. In fact, most of the parts will be made by the same companies!

The latter. get the unit modded if you can, but don't use any sleep. The "real" refinements of the last twenty years have been with source components (CD players and analog front ends).

Aaron

I don't agree with respect to SS evolvement. 20 years ago, semiconductors could not handle as much power as the ones made today; more were needed for a given power output. Today these devices can handle more power so, at least on paper, less devices for the same power rating should yield better performance. I'll be willing to bet that if the Belles 250 had today's semis, it would sound even better IMO.

. . . 20 years ago, semiconductors could not handle as much power as the ones made today; more were needed for a given power output. Today these devices can handle more power so, at least on paper, less devices for the same power rating should yield better performance. I’ll be willing to bet that if the Belles 250 had today’s semis, it would sound even better IMO.

I agree. The overall circuit designs don’t change very much, but the quality of the component used have much improved over the years. Electrolytic capacitors not only age over the years to the point where they can make a once great sounding amp, preamp, etc,. sound down-right bad now. New generation high-quality electrolytic capacitors are much better in all respects and last longer than the best that were available 20 or more years from the past. Also, many older amps used carbon-composition emitter resistors which rapidly age and will change the overall sound of the power amp. Now, amp builders often use non-inductive wire-wound emitter resistor which don’t degrade over time in their highest dollar SS amps and use quality metal-film emitter resistors in their mid- to lower-price amps. Finally, you can now buy a group of quality output devices (transistors) that are practically matched out from the box. Years back, many hi-end amp builders would buy a large quantity of of output devices and curve-match the for each amp - a very time consuming process. Early generation Threshold power amps comes to mind as that’s what they did. Now an amp builder can just place an order for a few thousand OnSemi (formally Motorola) devices and install them right out of the box with confidence.

or has electronics at this level not evolved that much outside of "subtle refinements"?

@phasecorrect 

In the 1980s there wasn't a single amplifier design made that had sufficient gain bandwidth product to support its feedback across the entire audio band. As a result, as frequency is increased, when designs meet that limit, feedback falls off (on a 6dB or greater slope)- so distortion increases with frequency above that point.

That's one of the reasons solid state has a reputation for harshness and brightness, and a reason tube amps are still produced.

But, solid state has evolved so that a solid state design can be as smooth as the best tube amps thru the mids and highs (where its important) because it is not possible to generate the gain bandwidth product needed so that distortion vs frequency is a flat line across the audio band. This relates directly to smoother sound due to how the ear perceives distortion.

I would not call that incremental or 'subtle'.

20yrs ago +18yrs - this is an old 2005 thread

My  Sansui alpha dated  back from 1987...

I tried to replace it with an universally acclaimed tube amplifier with a new technology  ...The return cost me 300 bucks in loss ...

I kept the headphone out from the Sansui for my top headphone  because there were no comparison for my headphone at all  ...

Vintage dont means outdated in all case and for all use ...

 

I think we get what we pay for. When I was shopping the Adcom, B&K, NAC, Carver, etc components of that era they all sounded pretty much the same, They all probably used similar topology and second from bottom parts. I brought home a Krell and it wasn't expectation bias that made the sibilance from my speakers vanish. 

Belles made good stuff so it holds up. 

I still fondly remember my old MC2100 amplifier, made in the 1970s. I had it restored by Terry DeWick before he retired, and I for damn sure should’ve kept it. Ugh! Kicking myself over that.

There’s been both good and bad sounding solid state gear, ever since it was introduced. There always will be. One problem with solid state is that good sounding audio-purpose transistors often go out OOP (aka "obsolete"). It’s a much worse problem than with tubes. With tubes it’s also harder to make something that sounds bad - you have to really mess up.

My mid nineties Krell KSA200s is fantastic to my ears. Smooth, dynamic and very powerful. Would love to hear it side by side with a new ss amp in the 10k range. Going on 30 years old but looks new inside. Not sure if there has been any service over the years. 
 

50 year old Sansui AU9500 has qualities with semi efficient speakers I feel is hard to match today.  Very bouncy sound. Really fun.