ARC Ref 6 VS. Vac Renaissance MK V

((((Have heard the Ref 6. Was super detailed and transparent but very forward.)))

I totally disagree.
Could it be the fellow who played it had his speakers too far out into the room causing a lack of foundation or meek power response?

Perhaps the speakers you heard it with were light n bright and were not to your preference?
Warmed up properly, Broken in 400 hours?
 Highly dought it was the Ref 6 it's a pretty amazing machine.
When partnered with other well-designed gear it plays extraordinarily .
 JohnnyR
 ARC dealer

Vac is a better sounding preamp more neutral and more musical.Vac also has great service as well.

I have not heard either of your two choices but I do own the Renaissance mk1 which replaced an Audio Research preamp.  The build quality of the VAC is superior to the AR if that matters to you.  I would take the VAC without thinking twice.
The only limitation I noticed on the mk5 is only 3 inputs plus the phono, so if you have a lot of things to connect you have a problem.

I have the Ref 6; it was indeed a bit too forward and lean in bass when paired with a Rogue Ares Magnum phono stage. But recently I paired it with the VAC Renaissance stand-alone phono stage and WOW! That combination blows me away. At this level of gear, matching is crucial. Soon I’ll borrow my dealer’s Renaissance V line stage (when my new SE phono comes in) and see which wins. But the control of the Ref 6 would be extremely difficult to give up for the crude motorized analog pot of the VAC. I absolutely adore the ARC’s digital volume and balance control, etc.

I also used to own the Renaissance III line stage some years ago, and my impression is that the Ref 6 is notably better. But the V is interesting with its use of 6922 and transformer coupled outputs.

the build quality of the Ref 6 is spectacular, btw.