Audio Research or Luxman?

+1 for Nobel for volume pots. Would be very surprised if there is not an equivalent that can be used, only issue may be space to fit. As for balance control, would suggest it is not required.

If not Nobel I would hope that any reputable service engineer would be able to find a good quality suitable pot that would fit and probably better than the original.

@audiojerry 

You might find this guide to identifying pre 1990 6h30-DR’s useful, they are expensive but you only need a pair 

http://www.aca.gr/index/hiend/hiendArticles?row=1988

I don't know specifically, but after years of a Luxman CL-32, I put an Audio Research SP-6B in my system and it woke-up.

I always wanted an Audio Research pre-amp, but could not afford one.  The old one I got used was in perfect condition and sounds 10x better (more accurate) than the Luxman ever did.

Not sure if that is true with the 2 items you are auditioning, but BUY WHAT SOUNDS BEST IN YOUR ROOM and forget all the "opinions" we have.

Cheers!

It depends on what level of Audio Research you are talking about.  For example, within the last month I had a one hour audition of Wilson SabrinaX speakers both with the Luxman L509x integrated amp ($10k) and also with the ARC separates LS28 and VT80 stack (about $20k).  I preferred the Luxman as being more dynamic with better grip on the bass and just a better presentation.  DAC was a Chord dac.  So it depends.

Personality I didn’t have chance to compare, but close friend of mine was using his  Luxman 507ux as a preamp with his tube monoblocks for years and was pretty happy with SQ until he tried Bespoke passive preamp instead. He was really shocked with the SQ improvement at all points. I understand that every setup is different and his experience couldn’t be dogmatic for everyone but the outcome was pretty interested.