KT120 in Audio Research Pre-amp?


I recently exchanged my totally worn out 6550C's for KT120 tubes from Tung Sol in my VT200 MkII. It required a small modification, I'll spare you the details, but it was a succesful operation, quite happy with the sound of the KT120's.
I have some spare KT120's and I was wondering.... is there any danger in replacing the Svetlana 6550C of my Audio Research Reference 3 for a KT120 tube? Since it is a risk-free replacement for most ARC-poweramps, I was wondering if this would be the same risk-free replacement for their pre-amps like a Ref3.
128x128midcall
No. In NO case the 6550 should be replaced by other type of tube in the ARC power supplies. Even the new REF250 still has the 6550 in this position.
Microstrip! Barely recognize you over here, relative to WBF! ;) May PM you over there for some advice...
so , no problem what I did two years ago , replaced the original 6550 tube by a NOS Tungsol black gitter , replaced in the REF 3 , and the CD7 .
regards Hans ( the Netherlands )