Tube Amp Archive

Hi everyone. I‘m in the process of converting a 2x6L6 combo (Roland Bolt) that into a Dumble clone (hopefully). Now I need some advice on what values I should use for neg. feedback since the OT only has one 8 ohm tap but the diagrams I‘ve seen so far show the signal taken from a 4 ohm tap. Should I ...

Yes, of course that cap had to be there. Silly me. The loop works fine now, thanks for putting me on the right track!

Thordur

Maybe there is a leaky cap, even if the amp is built quite recently. I must admit that my version of the Dumbleator loop is somewhat simplified. I omitted the bright switches along with the 10M/0.22uf/10M neg feedback chain. And since the input is already taken off V1B thru a 0.05 cap, I saw no reas...

Hi everybody. I recently added a built-in Dumbleator based effects loop to my HRM OD clone. The loop seems to work reasonably well but when it is switched on or off (with a manual dpdt bypass switch) I get a rather loud “thump”. And what is worse, engaging the OD when the loop is in the cirquit now ...