Boomerang Woes

[Mike Killian <kili@swbell.net>]

One of my Boomerangs is starting to sound crappy on playback, signal 
sort of breaking up or degrading.  This is especially noticeable in the 
lower registers of my guitar but is present throughout.
I have tried tweaking the pot on the back and can only get it to sound 
worse.  I have checked cables, amp inputs, etc. and I am sure the 
problem is with the unit..............Any suggestions?
(of course I have a gig coming up Thursday!!!)

Mike Killian