???What's The LEAST Expensive "End Game"Amplifier You've Ever Heard???

I can happily live with my Ayon Spirit III for the rest of my days.

The new Sprit V can use KT-170 power tubes vs the KT-150s of the Spirit III.

I have no desire to change my amp.

tave5,

I agree, the old Nimis is a terrific sounding tube amp--dense sounding but still lively and clear.  It is a lot of fun to listen to that amp.  There current Roma 96 amps, which run EL34s also sound very good and remain a screaming bargain.  They use to make a tiny 6L6 amp that I liked a lot too.  My only concern with the smaller Synthesis amps is heat build up under the chassis--they need to be well ventilated to reduce heat; I've seen a few of their amps that needed service because certain components inside the chassis got cooked.

As I mentioned above, I own two tube amps that are very expensive.  One costs close to six figures, the other one is probably worth about $45k.  While I don't think any Synthesis amp beats them out, I would not be that upset if I had to replace them with a Synthesis A40--this amp is worthy of any system needing only 40 watts at peak.  

If you can get your hands on one of the 100 limited-production VPI 2990D Integrated Amps, go for it!!!
A full Tube Integrated Amplifier that really sings. They came up for sale less often than before and they will be everywhere between $2,400 and $3,200. It is built in the USA with mostly USA-made parts and has a very decent flexibility for rolling different tubes which can really tweak the sound of your music.
This may be true of all Tube Amps, but speaking for this one, it will be your endgame Integrated Amp with tube rolling (sound tweak) options!
The only caveat I have is that the MM Phono Preamp seems to be solid state, and although it has really great sound some unites have a subtle hum that can get in the middle of the listening experience... Nothing that would deter me from buying it again.
Good luck with the search and, please report back on your decision and experience with it.

I have been very pleased with Accuphase and consider it to be my ed game SS Preamp and Class A amp. The integrated are also excellent. I would look at something which fits your budget, definitely used, these are built like tanks.

Audio Research Reference 160.