How to add EF86 channel to Cathodyne PI

[tubeswell]

Be a bit more gain if you went to an LTP

[Shamadan]

Yep but with LTP it would be difficult to use one tube reverb on all channels.

[jazbo8]

Be a bit more gain if you went to an LTP

Doesn't that move away from the Tweedle Dee design?

[Shamadan]

Yes that was also my concern. EF86 is supposed to be only something extra. Will see how it will cooperate with Tweedle-D cathodyne.

[tubeswell]

Here's a LTP concept - verb could be on the non-EF86 channel. If doing a 1 tube reverb, consider using a triode/pentode tube like an ELC82 or an ECL86, with the pentode as the driver. The EF86 and normal channel are on the same supply cap in the power rail. If you get oscillation, then split the supply rail into two after the PI supply node, and give each channel its own filter cap. That way you can get more control on the pre-amp stage voltages too.

[Shamadan]

Thanks for schematic. First I would try 12ax7 tube driver/recovery- lots of positive reviews. If I don't like it will try 6BM8/ECL82 for more reverb.