| Author | Message | ||
| Brad Carter |
I just bought a 112 RD 100 and after a couple of days of playing it the distortion channel started cutting out and finally quit. I haven't had a chance to play for a couple of days so the amp has just been sitting there. I turned it on tonight and on a whim I hit the distortion button on the footswitch. All the sudden it works again, though it sometimes cuts out still. I also noticed that the clean channel isn't putting out as much power as the switched channel now. Any thoughts, suggestions? I have replaced the power tubes with known good ones and that still didn't help. BTW, the pre-amp is solid state in this amp. Maybe I need to take it to the Amp Doctor and get a checkup? TIA | ||
| Steve Kennedy |
This could be caused by many things, but it sounds like you have a bad 4066 CMOS switch chip in the preamp or something related to the switching. There are a bunch of switch sections that are activated with the footswitch and if any one of them is non-functional, intermittent or leaky you will have symptoms similar to what you describe. The parts are common and cheap if you want to simply replace them all (the "shotgun" approach) if your troubleshooting skills aren't all they could be. | ||
| Brad Carter |
Steve, thanks for the reply and the suggestion. I may just go ahead and do the "shotgun" method and replace all of them. My electronics troubleshooting skills are definitely not all they should be! Thank goodness for good techs! Thanks Again. BTW, in case I haven't mentioned it yet, this site totally rocks! It's great to have such a great repository of knowledge for such great amps as Music Man. |
Tue, 03/25/2014 - 09:57
#1