fthompson251

you are a man with a plan, impressive.

It's very nice to get a vintage piece back that has been properly checked over by competent people you trust. I visit a friend who lives a few miles from Audio Classics, I feel they are in my back pocket!

I see your amp has 6SN7. My Cayin has 6SN7's and 6SL7's. I mixed em up by mistake, blew one. Researched, picked a matched pair from Brent Jesse, I was very surprised at how much difference in sound they made, in my case not good. I was able to send em back, try another pick, they sound equally wonderful as the ones Cayin used whatever they are. Just saying, I would ask VAC some advice about recommended 6SN7's for yours while they have it. 

@elliottbnewcombjr  I still have the Golden Dragon 6sn7's and I have  back up complete set of tubes for the amp (8-300 Bs and 4 6SN7 Golden Dragons), they came with it when I bought it, but I bought all new tubes for it when I got it to start out with "freshies". It was used but gently with little time on it as I remember. I am looking into some Tung Sol USA black base but trying to predict a sound signature of a tub cab be tedious. 

Hornets 🐝 nest

There are some notable newer designs:

Lavardin - low memory 

Halcro - low distortion

the thing is that class a amps haven’t changed in essence

many classics they just got right. Some old components were just better:

old valves

old jfets 

some say tinned copper wire

But there is a lot of rehash of various topologies

My Sansui Au 7700 so good it was and so good it is right now will not compete in sound quality ( his versatility is unmatched though) with the Berning ZOTL technology which is  a bargain it seems in Audio offerings...

My exemple is valuable for other brand name for sure...

But my Sansui is enough for me twenty times less costly .... 😁😊

It was a legendary product and it is enough to reach heaven  especially in a controlled  acoustic ...

There is always progress.

But to answer your question:

Can a Amp be "timeless" and compete with todays amps?

The correct answer is ’no’. The single thing that has held back amplifier improvement is something called Gain Bandwidth Product (GBP). Over the years you may have noticed that feedback in amplifiers has gotten a bad rap. This is because limitations in GBP have prevented enough feedback from actually being applied. The result has been that the application of feedback has resulted in added distortion on account of the feedback itself, and increasing distortion with frequency above a certain point.

This has caused feedback to be conflated (and rightfully so) with harshness and brightness.

What happens if there is insufficient GBP is that the feedback starts to fall off at higher frequencies and so with less feedback comes greater distortion. If you graph distortion vs frequency you can see this in almost any amplifier made in the last 60 years employing feedback. Since the ear converts distortion into tonality and since the ear is keenly sensitive to the higher ordered harmonics generated by feedback itself, the result is harshness and brightness over the last 60 years.

That is why there are many zero feedback amplifier designs. Zero feedback is about the only traditional way of getting around this problem.

If you can manage about 35 dB of feedback in the amplifier design and there is sufficient GBP, the result is that the feedback can ’clean up’ its own mess, resulting in less higher ordered harmonics. Since the feedback is consistent at all frequencies, the distortion and the distortion signature (the spectra of harmonics) does not change as frequency is increased.

Its a simple fact that no tube amp is capable of this! You need a lot of gain and a lot of bandwidth; the former is simply not available in tube designs without associated phase shift, which would cause the amp to oscillate at some higher frequency.

There are now designs that satisfy these goals, designs that were not possible 20 or 30 years ago because the amplifying devices didn’t exist.

What this means is its possible to build a solid state amp that is every bit as smooth in the mids and highs as the best tube amps and leave nothing on the table in terms of detail, sound stage and the like, in such a way that vintage amps simply cannot compete (not that they sound bad, just they don’t sound as good). This is one of those things that is easy to hear and easy to measure.