ARC Ref 3: Tung-Sol 6550 in power supply?

Being involved in this hobby for well over 35 years has always shown me that when something is changed I always ask "did I hear something different or did I hear something better"

Perhaps the chaanges in your system is what minimized fatigue as you were hearing something different, not neecessarily better. Nonetheless hearing from you about your conclusions will be informative

Marco_esposito - your findings seem to confirm what Guido has written before - the current production TungSol 6550 (so called "reissue") does not bring a net benefit compared to SED 6550C.

When I was talking about the improvment I got by inserting a TungSol 6550, I meant the NOS (New Old Stock) TungSol 6550 Black Plate from the early 50s - which is a totally different tube to the one you have tried.

I cannot recomment it (NOS TungSol Black Plate) highly enough.

As anticipated here you can find my system to better understand my findings:
http://forum.audiogon.com/cgi-bin/fr.pl?vopin&1220291925&view

Marco
beautiful looking room