Best 6550's for ARC VT-100 MK3 amp- SED; Tungsol??

Just picked up the amp- I believe the stock ones are in there now- Sovteks?? Good bass; dynamics; perhaps ever so slightly 'glassy' on top at times- they could be older- not sure...

I have heard the Svetlana (SED) 'Winged-C' are good? Apparently, it's difficult to know if you really are getting SED's though, and not the Sovtek equivalent...

Also- what about the Tungsol 6550 reissue- how would they compare to above?

I assume that your bias is correctly set at 65ma. I also assume that you have removed the oxides from the 6550 pins by using flitz cleaner. If so, the 6550/KT88 from EAD are the way to go. See HiFi+ for details.

The EAD's are just rebranded and marked-up run-of-the-mill tubes -- EAD is doesn't manufacture tubes. Don't waste your money. IMHO, The best sounding 6550/KT88 in current production is the Penta Labs Shuguang solid plate KT88, which is designed after the reknowned Genelex KT88. Feel free to e-mail me for more details.
My amp is a VTL, not an ARC. I tried the new Tung-Sol 6550 and didn't care for it in this amp (same story with the SED KT88). I like both the SED 6550C and the Electro-Harmonix KT88 better than the others I tried. The latter is my own long-term choice, though the former is a warmer-sounding tube, and to some may better complement the sound of an ARC. However, I believe ARC does use EH power tubes as original equipment -- I haven't heard the EH 6550, which might be the stock tube in your amp. In any case, there is no difficulty identifying or obtaining the SED 6550C (St. Petersburg factory) as opposed to the new Svetlana (Reflektor factory, same as Sovtek/EH) -- only the SED has the Winged-C logo printed on the envelope, and most tube-supply houses carry it. If you have an indication that the tubes in your amp may have been used for 3 years or longer, then you should go ahead and retube whatever your choice is.
many thanks guys- great responses- I may e-mail a couple of you for more info...
The winged C 6550's are stock on the VT-100 MK3. Since that amp was voiced with the winged C thats the tube I would go with. G. Garfield
I have used SED and Tung Sol 6550 in my VTL ST150 and I found the Tung Sols to be more to my liking. The Tung Sols had a firmer bottom end in my system. The SED sound was more open and airy than the Tung Sols but not by much. I felt that it was a good trade off and have stuck with the Tung Sols. I do want to try the Shuguang KT88-98 but that will have to wait a few years untill the Tung Sols wear out. Rolling output tubes gets expensive!