Tubes for VTL S200

I know it’s subjective and circuit dependent, but I really like the Tung Sol 6550s in triode in my Dyna/VTA monoblocks with an EH 12BH7a driver tube.  It’s the Goldilocks combo for me.  I’ve liked EH-EL34s, Siemens SL-34, GL KT66, and really liked the Tung Sol 7581A too, but those TS 6550 make me smile.  The EH6550 didn’t do much for me.

Have owned quite a few of the VTL monoblocks but not the S200. The EH6550s are nice, so are the EH KT88s. You may want to consider adding a 0.1uf film cap bypass to each of the main filter caps. Will remove a ton of the noise that gets modulated through on the B+ rail. 

Don't forget the 12AT7 input tubes and 12BH7s. Try to find RCA or Sylvania black plates to plug into those sockets. 

I had an awful experience with an S400. I bought tested, aftermarket tubes from reputable resellers because the original VTL tubes (6550s) that came with the amplifier got nowhere near the 'advertised' (website) and in the S400 manual, 'average' life of 3,000 hours. And they were twice the price. The aftermarket tubes were slightly but not much better in terms of reliability. Thinking this was an amplifier issue the local distributor went back and forth with VTL who insisted that only VTL tubes be used. I bought a matched set (12x KT88s) only to have 8x of them fail in less than 1500 hours.

The KT88s were more detailed and dynamic but less 'flesh-on-the-bone' compared to the 6550s.

I sold the S400 and note VTL removed statements on their website referring to their autobias function delivering the 3,000 hours average.

If you don't mind VTL not offering support because you're not using their tubes, then go for it!

YMMV.

That’s pretty interesting and terribly discouraging. Especially being that in a review I read where, and I might be getting this wrong, VTL offered an upgrade in tubes(maybe kt 88s?) for an extra $400 with the S200.

I just purchased GL KT88s. I hope I didn't make a huge mistake.