6550C vs 6550EH in Audio Research amps

My experience is with a pair of ARC VTM 120 monoblocks that ARC tubed with the Sovtek 6550"B" tube. back in the mid 90's. Later they went to the "C"..but I think for all intents and purposes it may sound quite similar. I tried matched quads of the 6550EH tubes sourced from the tube store just before selling my amps last year. I felt that the EH's were somewhat rolled off on top and thought I may have lost some definition over all. After about a month, I put the stock 6550 Sovteks back in and was more satisfied with the sound of them in the end. Just my experience FWIW...enjoy!

Hmmm..., Yes, I'd also like to try the 6550EH. I just used the newly relabled 6550C from SED (the company formerly called "Svetlana"). One of the tubes was apparently poorly made and after use for a while, it suddenly shorted internally. It fried several of the parts in my ARC VT-50 when it lit up like fireworks. I'll probably try the EH when my amp returns from an expensive repair. :(

Holos