Audio Research Ref 10 vs 40th Anniversary preamp

Respectfully, techno_dude,... I do not agree with your comment.  The Ref 6 is a wonderful preamp.  The SE upgrade made the Reg 6 sound better.  I understand that the changes consisted mostly of new caps and wire.  

ARC is constantly trying to improve its product line.  If upgrades to one component can be transferred to another product, ARC oftentimes will do that.  For example, ARC made SE improved its Ref 150 amp, the Ref 6 preamp and the Ref Phono 3.  

I own the Ref 150.  ARC did the SE upgrade several years ago.  The upgrade included changing out the KT-120 tubes for KT-150 tubes, plus other changes.  I can tell you that the SE upgrade significantly improved the SQ of my Ref 150.  Ditto re the Ref 6, which I used to own but had upgraded to the SE version.

Anyway, that is my opinion. 

So Ref 6 or Ref 6se or Ref 40 or Ref 10 ???

i am still running my 5se, 5 k happy listening hours later…..put HRS Nimbus couplers under….

lovely….

Any recommendation on wether to get the ref 6 to 6 SE upgrade for $3k or trade in the old ref 6 and get a new 6SE for $5500?

@tomic601 I got the 5SE used for a decent price about 6 months ago. I am blown away by it.