KT 66 Rocket and seperate Bias resistors

[Markusv]

Good thread... I'll try not to louse it up!!!

I didn't use two cathode resistors but only because I had not done enough homework... I'm curious of the results.

Tube spacing... I had that wrong too. I used an Express chassis to build my prototype in and the output tubes are pretty close together.
rj

As reported before, my build was in a Judybox chassis
Steel chassis and I am really not keen to start re-drilling tube socket holes
The spacing is very narrow so with some trepidation I installed the KT66's
They seem OK and I also noticed that the spacing specified is for tubes running under max conditions. My voltages are around 340 anode but based to about 70%.

With el34's the physical space between bottles is greater but obviously not between centres of tubes
Right now the shared cathode resistor is doing it for me and it is reassuring to hear that others use it too. Not sure I will go the double Rk route.

BTW- I installed 2x10" speakers in my combo. The one is a pull from a Bassman re-issue and the other is a Heppner Alnico from an organ. (I have a very vintage PR10 but people tell me they are rated for only 15 watts so I went with the Heppner because I'm not so concerned about it and I don't want to blow the Jensen)
I am sure I could do better with some nice Weber vintages or a Redfang/ Ceramic combo but I must say I am VERY pleased. Much better than the 2 similar ceramics I had in before

Again thanks for all the replies and also the new insights

Markus V

[Zippy]

The spacing is very narrow so with some trepidation I installed the KT66's. They seem OK and I also noticed that the spacing specified is for tubes running under max conditions. My voltages are around 340 anode but based to about 70%.

Markus, considering that you bias to 70% and that it is very difficult to run a guitar amp at full output for any duration, I think that your spacing between the KT66s is sufficiently safe. I say this knowing that RJ is running his amp with MY KT66s in the same configuration.

Thanks for sharing your progress and success with the amp. I enjoy the 2-10 configuration - glad to hear that it's working well for you too.