Hello,

I'm back to tell you that all is ok now : bad preamp tube.

I didn't know that a bad preamp tube could do such a mess in the sound

Thanks

Hi all,

I'm new to this forum and i've registered unhappily for a bad news : my 1987 head with PPIMV (Sozo cap) has very bas bass and not proper sounding to my ears. Symptoms :
1 - When I turn it up with stand by on, there is a quite loud humming from the head. Like buzzing.
2 - With stand by off (ready to play), plugged with any guitar (except Strat where it's quite ok) into high channel only, the sound is really ok if I do not attack too much. If I attack more, any bassy note (let's say a G on first string) is muddy, mushy. I have not the stretchy/fuzzy grain of a fuzz as I improve the gain, but more... disto/harsh/noise.

The head is just out from the tech, who changed the power tube (paired) and biased it. He noticed nothing by himself on the buzzing and bad sounding : he is "not a Marshall guy" as he said so he did not take interest to the sound.

Any idea ?

Many thanks ad sorry for my english.
TeuF