bass problem with master volume

[fopoman]

I can't turn up my master volume past 4 without getting this feedback bassy sound. you know the classic woooom sound. It's a twreck clone amp with a post PI MV. Any help would be appreciated.

thanks,
Nate

[David Root]

What coupling cap values are you using?

[drz400]

power tube sockets (inputs) too close to the speaker jacks?

[mlp-mx6]

Have you tried reversing the output xfmr leads on the power tubes? It could be your neg. feedback circuit is actually a positive feedback circuit.

[fopoman]

Thanks, folks. I don't have the internet at the house so I have to borrow a computer. It ended up being the leads to the output transformer. I reversed them. I used bruce collins Master Volume from blueguitar. It has to be one of the best Masters out there. I love it.

thanks,
Nathan