Svetlana KT88 VS EH6550

Dmailer, did you send amp to SF to repair? If so, I guess they told you not to use KT88. Interesting that SF put them in their SE versions if they consider them unreliable. How do they explain that away?

I thought the SF amps were very reliable, but lately a salesperson who used to sell lots of them told me that they were not reliable. Wonder what others experience is?

Forgot to mention that it could have just been a bad tube. If the tube is bad it will blow the resistor. Doesn't mean the amp is bad design.

The resistor blew yesterday and I suspect it was a bad tube. I plan to call them tomorrow and see if they will send me some new resistors so that I can intall rather than sending it back to the factory. The tech people had told me that the early Svet KT88's had alot of problems and thus they are now not recommending them. Of course they are no longer selling amps but are still maintaining them. If the 6550 is more reliable then they are probably discouraging the KT88's in order to minimize the repair issues.

You should also consider going with KT-90s.

Kevin at Upscale Audio can help you with matched set.

I just spoke with Chris Johnson at the Parts Connexion regarding the recommended tubes for the Power 3's. Chris was president of SFI and knows the product better than anyone. He strongly suggested the Svetlana KT88 tube as the best option. He said the 6550 variations do not sound as good on these amps as the KT88's due to the higher plate voltage. He is sending me new tubes and some replacement resistors. I would suggest that anyone looking to retube an SFI product contact him.