Simple SE with kt120?

[nightanole]

You think this might work with a 400-0-400 transformer? Edcor has some nice 800vac transformers and you would get what, 25watts at least in ul mode.

Triode mode you could get 20 watts if you bumped the b+ to over 600 volts, but what to do about b+ cap selection (or even resistor selection at that voltage) and taming the driver b+ back down.

[Ty_Bower]

KT90 is the "biggest" tube I stuck in my Simple SE. Honestly, I felt it sounded a good tube but really needed more kick behind it to live up to full potential. I understand the KT120 has more in common with the KT88, only with higher dissipation limits and drive requirements. Regardless, I'd imagine my observations would apply. My power transformer is a Hammond 374BX (rated at 750VCT) and at the time I was running a moderately tame 810 ohm cathode resistance.

If you want to try KT120 I'd suggest you have plenty of volts and amps on tap. Keep an eye on the voltage ratings of the power supply caps (C1, C2) and don't forget about the cathode bypass caps (C12, C22). At high currents in the finals, you are at risk of exceeding their rating.


http://i69.photobucket.com/albums/i4...E/P1120152.jpg

[nightanole]

ya know i never noticed it was just a cap in the feedback network...

[rknize]

I've also run EH KT-90s in my SSE. I like to run them as triodes with the switchable bias at full tilt, which is about 100mA per plate. They seem to take it in stride. The KT-120 may be similar, but they are a bit too rich for my blood at this stage.