mono versus stereo ampflication

Many mono's do have better power supplies & transformers etc. They are "overbuilt" to a higher level if you will.

Going from the Aragon 8008BB to either of the Pass models you mentioned with the VR4 Sr's might be disappointing in the bass and dynamics but would sound more refined in the mids and highs.

The problem is the $8K budget for monoblocks. It can be done but you might have to get used or go to some of the class D amps for similar grunt as the Aragon. You could run dual Plinius SA-102's, in bridged/balanced mode for 400W/ch for about $3K each used, except you'll probably want a preamp with balanced outputs.

Responding to comments and questions:
Rleff - I am planning to use my Audio Horizons 2.0nB preamp in balanced mode and connect to Von Schweikert VR4Sr's by biwiring.

Peterayer - I heard the XA100.5's in a friends system a few weeks ago and they started this search for better amplification. They sounded (as part a a great system and room) incredible. Congratulations on your choice. I am trying to approach that sound a a bit lower the price. Best I understand from reviews the INT 150 was designed to function much like the XA.5's for the first watts

Grannyring - thank for recommending the TRL's. I will check them out. Have you heard them compared to Pass?

almarg - Great suggestion - I have been concerned with energy use,cost and heat with the class A, but am hearing from reviews that the XA.5 are a very significant improvement. Does make sense to see if I can to hear the difference in my system.

I thank everyone else as well for their input.

How about VAC amps.
They do sound right with your speakers.

Another consideration might be the DAC Cherry amp which is awesome for the bottom but a bit sterile at the top.....at least to my taste.

Pass is a great amp but unfortunately I haven't got a chance to hear it with VR4Sr so I can't say hey or ney. Nice amp tho.

The TRL amps are single ended only. I have not heard a Pass Amp and understand they are quite good.