I bought a used dbx subharmonic synth off of ebay and it finally arrived today. I hooked it up, and 2 of the knobs are wonky. The subharmonic knob has a click at around 9. I'm not sure but I don't think the unit processes *at all* until after the click, so my adjustment range is from 9 to 10. Also, the 24-36hz knob has a less pronounced click (more of a whhoomp) around 9. I do think it works below 9. I like it overall. My sound is definitely fatter. If I crank the subharmonic knob, I can use the two frequency knobs to control how much effect I get, right? I have a gig tonight (Texas Arizona in Hoboken across from the PATH station for anybody nearby!) and it's already racked so I'm going to use it, even though I usually like to try new gear out at rehearsal first. What should I do? I already sprayed a *lot* of contact cleaner, w/ minimal results. Should I send it back? Pay to have it fixed? Just leave the sub knob at 10 and use the frequency knobs? Any advice from techies or dbx subharmonic users is appreciated. Thanks!