36w lite II

[Calamardo]

Here i come again.I made a 18w lite II and its sound amazing, but i need more clean headroom, and i wonder if you can help me to understand how can i make a 36w lite II. Can you show me some layout? im just a builder i dont know much about how work the power amp section. And the last question: is possible switch between 2 and 4 el84? (like Matchles dc30).Thanks a lot !!!!

[markh]

All you need is to add two more EL84s, one on each side, with their own grid and screen resistors. Connect the two plates and the two screen together on each side.

You'll also need bigger OT and PT, but the connections will be the same.

For half power, just put a DPDT switch in to disconnect the outer two tube cathodes for half-power.

--mark h

[Calamardo]

ok! thanks Mark. another question: can i use only 2 tubes in this configuration or is neccesary keep the four tubes in their place?

[zaphod_phil]

I'm not sure what you're asking, as you'll need for power tubes to get your 36W output.

Connect the two plates and the two screen together on each side.

It's good practice to have a 100 ohm resistor soldered onto the screen grid pin of each tube, as with the Lite IIa and Lite IIb.
So basically you end up with two 18W power sections, joined at the OT. I believe Graydon can provide the bigger Heyboer transformers for a 36W.