KT88s...the final chapter

have not read extensive posts on this subject. but i have talked to a lot of tube dealers and some equipment mfgs. an expert i am not! here are my findings.

gold dragons are just select current mfg tubes. rogue uses kt88s in their magnum upgrade that are supposed to be select and matched for him. 300$ per 8. mark states that these are much better than the svet or sovtek. he also stated that they had good success with electro harmonix 6550 "tun-sol like in sound".

tube dealers all seem to say best kt88 is nos m&o and best 6550 was tun-sol. during the years of there respective hay day. i am saving to buy some used tun-sols (that test good)and should last many many years to come. as all stated these were the best sounding of the bunch. good luck

Jvr, I find it amusing how dealers will often say the most expensive tube is the best sounding.

Based on my very extensive experimentation, I can only conclude that different types of tubes sound different in different amps. I have come to regard tubes as a separate component in my system that needs to be matched carefully to everything else, just like you would match any other component in your system.

You may or may not like Tungsols. In most of the amps I have tried, they sounded pretty dry. Personally I prefer GE 6550's from the old stocks (yes, even over the Gold Lions). But then again, this will depend on your particular configuration.

A small note about the Svets: I have not tried KT88's, but in the case of 6550's I have found that they are hard to bias properly in a lot of amps. At 'normal' biasing points they might sound poor, but unexpectedly can really SING at some weird bias setting.

I have some interesting things to ponder.Any suggestions on used NOS TESTING 85% +.

Audiophobe, how much higher ma setting did you go to make them sound good? Thank you.....Frank

At Upscale Audio we have sold them all...and it depends on the amp. You have tobe careful when talking to dealers about "whats best". I had a customer tell me that suddenly the Svetlana KT88 was "not as good as it was" according to another dealer. I asked this customer if that dealer had them available. Guess what.He didn't.

There is no doubt the GEC KT88 was king of that type. And the same for the Tung-Sol 6550. And we have nice stocks of them. But I cannot tell a guy that they are worth the money. The guy that has to think twice about laying down that kind of jack may want to spend his hard earned bucks elsewhere.

As to the Slovak KT88...I will not sell them anymore. They are trouble. Anyone who knows anything and is honest will tell you that. I was one of the first people in the U.S to get my hands on some...and have tried three "revisions" and still don't trust them. They have blown up tha amps of customers that I care about. It's not worth it.

If you have an ARC or Sonic Frontiers or any amp with no plate fuse,the safest bet and most predicatable tube is Svetlana 6550C and KT88. There were disruptions that caused shortages...and in the meantime folks tried to sell off the brand regardless of if it was in the customers best interest.