EL34 to KT66?

[rockon1]

Is this a safe swap assuming the bias is set for the KT66? thanks Bob

[jrfrond]

They should drop right in, aside from the bias setting. However, if you are looking for a drop-in beam tube replacement with similar bias settings, scope out either some NOS or E-H 6CA7's. In the "old days", 6CA7's were often labeled "6CA7/EL34", because even though they were/are different tube types (beam-tetrode vs. power-pentode), they had similar ratings and bias requirements.

[rockon1]

Thanks. I wasnt sure if anybody was actually making real 6CA7's but I'd like to try them as well -for that matter Im not sure if anybod is making real KT66's either! lol! Bob

[defaced]

JJ makes a E34L (6CA7). I've got a pair and am satisfied with them, but I think I'll end up switching them out for KT-88s.

[jrfrond]

I'm almost positive that the E-H 6CA7 is a modified version of their 6L6GC, as the plate structure is identical. In any case, these can and do sub for EL34's directly, as I have done it here in the shop. "Real" KT66's? Not sure about that. A lot of reissued tubes are rebottled and/or repinned versions of more common types, e.g. 6550/KT88. "KT" or "Kinkless Tetrode" was/is a very specific, highly-linear design spec for beam-tetrode tubes, but I suspect that the new KT-xx tubes we now see are, as I said, just garden-variety beam-tetrodes.

[rockon1]

JJ makes a E34L (6CA7). I've got a pair and am satisfied with them, but I think I'll end up switching them out for KT-88s.

Yeah the amp came with E34L's(Rivera Chubster). JJ does make a KT66 though. It has a metal base tied to pin one but seeing as the amp uses EL34's i dont think its an issue.

I'm almost positive that the E-H 6CA7 is a modified version of their 6L6GC, as the plate structure is identical. In any case, these can and do sub for EL34's directly, as I have done it here in the shop. "Real" KT66's? Not sure about that. A lot of reissued tubes are rebottled and/or repinned versions of more common types, e.g. 6550/KT88. "KT" or "Kinkless Tetrode" was/is a very specific, highly-linear design spec for beam-tetrode tubes, but I suspect that the new KT-xx tubes we now see are, as I said, just garden-variety beam-tetrodes.

Just looking for different options. I prefer the sound of 6L6's in the Chubster over EL34's. Thinking maybe the KT66's might give me a little different flavor. Ive even tried 6V6's in it but it was to buzzy sounding probably due to the impedance mismatch created. Bob