Screen Drive Push Pull ideas

[whitelabrat]

Yup. 6JD5's.

811A single ended triode power amp | Tube amps DIY

Interesting.

[tubelab.com]

The SV811-3 is NOT an 811A, not even close. The SV811-3 has a Mu of 3, works somewhat like a 300B, and isn't available any more.

I remember a schematic that used a 6V6 cathode follower to drive the grid of the 811A directly. Can't find it now.

[whitelabrat]

I've been looking at the *FJ7 tube. A pair of those look like they could be good drivers, especially with that hefty 10w side.

I was trying to modify an old Bogen MU15 to use 22JF6's as a guitar amp, but it wasn't happy. So I figure I'll use it as a mule for screen drive testing. I'm guessing the output transformer is rated for at least 15w. I'm not looking for horse power, just a proof of concept so I can better understand the circuit.

I didn't have any suitable transformers to provide 22v to the heaters so I bolted on a 40vac transformer and wired the heaters in series. Got nothing to loose. I get 20v on the heaters which I figure is good enough.

The power supply puts out about 400v on the B+. I figure this is good enough for 15w. I won't mess with 7W7's here. Just 6J6's and either a 6SN7 or a 6CG7 since there are already sockets ready to go.