Farting Ampeg 210ba SP

[McCartyLS]

Hey there, I am new to posting on here so please forgive my transgressions if I am in the wrong place. As the subject line indicates I have an Ampeg 210ba SP, when I try to use any of the distortion effects it momentarily gives a clean signal for a second, then makes a horrendous fart noise. It will do it over an over, deaden the note and play again....clear for a second....ugly fart noise. None of the adjust or level knobs have an effect on whether is makes the noise or not. I do not have the same problem on other effect types, like chorus or reverb. Any suggestions...clean the heck out of the insides or something?

Thanks for your input/help!

[KramerBassFan]

When you use effects, cut back on the bass a little bit.