Audio Research Ref 10 vs 40th Anniversary preamp


I was wondering what the difference in the sound between the Ref 10 and the 40th ? Not much wrote about that. I btw have the Ref 6 but never heard the 10 or the 40th. 
128x128Ag insider logo xs@2xtattooedtrackman
I had the Ref 5se and really liked it. I demoed the ref 6 from my dealer and couldn’t believe the difference in the 2 of them.  The 6 was better in every way in my system. I sold the 5 se and had to buy the 6 brand new. 
I concur with tattooedtrackman.  I am on the list for the Ref 6 SE upgrade, which I am dubious will make much of a difference.  The main changes are the power supply caps are getting switched out and some of the wires too.  I look forward to being pleasantly surprised.
I've always liked the Audio Research house sound, and looking into the 10 pre - reading this thread has been really illuminating. Thanks to everyone for your impressions.

I remember listening to an Audio Research amp and pre for the first time, literally a day after they arrived at my local dealer, who had just started carrying the line.

I was less than impressed. The treble would occasionally leap up and bite, and the overall effect was wooly in the lower midband and bass. I left, surprised that they would charge that much for the pair, as frankly my own less pricey tube gear sounded far better.

Fast forward six months later, and I returned to the same dealer - and those ARC boxes were playing in the same room. They sounded completely different - absolutely beautiful, with an extended and sweet treble, and a new clarity to the mids and bass. I couldn't stop listening for at least 45 minutes - they were hooked up to Wilson Sabrinas and sounded perfect, without deviation, the entire time.

I asked a staff member what happened, and he smiled nonchalantly. "Oh, they just finally broke in - all the ARC stuff does that, to varying degrees." He told me to prepare for a good 500 hours of break-in time, and they will reward your patience. That is so true for this particular line - it is a profound night and day difference.