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
Ref 10 for sure.  Have 1300 hours on mine.  Its wonderful.  Never heard any aggressive treble.  Its very musical. My friend was listening to the system while I was testing tubes for his ARC vintage preamp.  Said was sweet airy, excellent depth and width.  He loved it.
New REF6SE is said to close the gap to the REF10 and might be worth a listen.
Randy at Optimal is just a gem, give him a call.
@folkfreak what new speakers ? I have heard the VTL sing with Vandersteen 7 in San Diego
I think one had better be sure to replace tubes in the tube regulated power supply in the Ann 40  on a very regular basis...or be prepared for repairs that can get costly! Personally, I would take a pass on a design that utilizes tube regulation.
@tomic601 I changed from Magico Q3s to M3s -- the latter are much more even and rounded sounding and in combination with the ARC house sound was a bit too lush and enveloping -- the VTL was a better fit -- see my system description if you want more info