I built an 18Watt TMB about 7 years ago. It worked great for a bit, but then developed a problem where it would lose power, then recover, lose it again, etc.
For various reasons, including a gig that dried up, I haven't used the amp in several years. I mentioned on this forum that I had a problem (in an unrelated post about purchasing an OTS FM) and someone encouraged me to post pictures and a description of the problem here. I'm hoping y'all can help me figure out what's wrong.
Pictures are below. This was my second amp build (after a Gilmore Jr. kit from Gary Gerhart), and it shows in my soldering skills....
I tried the amp again today and here's what I found:
After playing about 10 minutes at moderate volume on the normal channel (i.e., clean), during which it sounded great, there was a sudden, somewhat soft "phfftftf" sound, and the power dipped way down. The sound distorted a bit in an unpleasant way. After maybe 5 seconds of fits and starts, the power came back, and it was fine for another 15 minutes (before I had to put it away for now). In the past, the problem has cycled on and off every 5-15 minutes or so. Throughout, I was getting occasional interference -- what sounded like RF interference to me. That may or may not be coincidence.
That's all the data I have for now, but I'll try to play it some more in the coming days and weeks and perhaps post more observations.
Any help much appreciated!! Now for the pics:http://photobucket.com/18WattTMB