I have an original Spider I amp (I think) that I bought a few years back, looks like a 210 amp, 50w.  The delay effect was a little busted, but manageable.  Now, it's out of control.  It is always going off and there isn't any way to turn it off, the knob doesn't even stop at 'off' it keeps going unless I press and hold the knob in the off position.  As soon as I let it go, it goes right back to being annoying.  I took it all apart and realized that the knob piece isn't going to come easily off.  I'm not much of a sodering guy, but if I need to replace this beast, I'll suck it up.  Any ideas on how to replace this piece?  Or can I order a new board to replace this defective one?  Thanks guys.