Question about Class A

@jay73  I agree that the SET 120 would be the better purchase as you would not need the additional power. Are you talking about the integrated version or the amplifier? AVA makes both. 

What are your sources?  If digital you would have to replace the DAC in the SV-500. At your budget with purchase of the 120 integrated you could purchase a tube DAC if wanting some tube sound in your system.    

I must say that I once owned a Vincent hybrid amplifier, the SV-226. It was class AB. I sold it and consider that move one of my audio mistakes. It had more power than the SV-500 at 100wpc and was line level only. Fed it with an outboard DAC and phonostage for sources. I would encourage you not to be in a hurry in your decision making. Continue to explore.

I am still at a loss to recall a class A 20+wpc amplifier that retails for ~3K other than the Sudgen. Not to say they don"t exist.    

I personally am a huge fan of Class A.  In the Luxman 509x/590axII issue, one being A/B and the other, respectively, Class A, ask yourself why so many 509x units come up for sale, and not long after being bought, but the 590, a Class A unit, is only rarely for sale.  I think the fact one is Class A is the factor.  Once I experienced it there was no going back.  I am trying to get there myself......

Also to point out, there are MANY Luxman M 900u Class A/B units for sale......but the older M 800a Class A units are rarely for sale too and I wonder why.......

@mesch , as far as AVA HiFi is concerned, I would consider the AMP, not the Integrated or Control Amplifier as they call it.

Either the SET 400 or SET 120 Amps with the Vincent functioning as a Pre-Amp, I think it would make a good combo. As you stated about your previous SV-236, I really would hate to give up my Vincent. It certainly is a sweet sounding unit.

But if I decide on the Sugden, then no, choice, I would have to let it go.

For my sources, I have an external DAC (Queststyle CMA400i), MoFi Studio Deck TT with a Hana SL MC Cart and a Technics SL-G700 SACD Player. So I feel my sources are pretty decent.

Yea, I am not in a rush, need to make sure I get the right unit.

@blackfly , I've never heard the Luxman's but I can imagine they must be awesome, especially the 590 that you refer to. Just way out of budget though. But they are beautiful for sure.

But you stated, I really want to hear what Class A is all about, Hopefully Soon.

You’re going down the right road looking for class A, don’t listen to anyone who says that a properly made class D amp has the qualities you seem to seek. A, A/B, D etc. each have a flavor.  Although some A/B are biased for a handful of watts at the top. .