Tell us about your KT150 experience

By now, there must be quite a few folks who own amps that utilize the Tungsol KT150 tube. ( I own a pair that do).
As such, i would like to hear the experiences that you folks have with re-tubing the amp with new KT150’s...what dealer did you buy from, how well were the tubes matched, how long have they lasted, any problems with the set or old set? What amp(s) are you using them in?...and lastly do you believe that they are superior to other Pentode power tubes...and why.
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Showing 1 response by decooney

For what it’s worth...

Comparing, re-tubing an older KT88 based amp that will "accept" KT150s vs. an amp which was designed day-1 (with larger transformers, and higher plate voltages) to natively run KT150s optimally, "can" "sometimes" yield a different listening experience. I’ve run across this with 3 different amps.

While I really enjoy the KT150s in my current mono block amps, they were originally designed to run them. Sounds great. However, a good friend just removed KT150s from his older amp, and he went back to KT88s as his amp was originally designed for them. In his case, I too preferred the KT88s in his amp. His upgrade to KT150s was a waste in his particular situation. Found out later his amp had much lower plate voltages, and (apparently) was not able to fully drive and take advantage of the more expensive TS KT150s.

It seems the amp/design/circuit has something to do with it as well. Probably worth checking with the amp designer to see if it’s worth it. A case of bigger or newer may not always be better.