Author |
Message |
Mike Griffin (mgriffin155)
Username: mgriffin155
Registered: 02-2014
| Posted on Friday, February 28, 2014 - 12:22 pm: | |
As I've been restoring an MM 112-RD-65, I've found the Dual 100K Gain pot for the Distortion Channel not quite right. The schematic reference designator has R.A. which I think means Reverse Audio Taper (anti-log taper curve). The 2nd pot tracks the 1st one fairly well until the knob gets down to 2. Then the 2nd pot goes way beyond 100Kohms. At 0 on the knob, it shows 785Kohms. I have looked Hi and Lo and am having difficulty finding a replacement. Please advise. Thanks, -Mike |
Mike Kaus (mm210)
Username: mm210
Registered: 05-2006
| Posted on Friday, February 28, 2014 - 03:45 pm: | |
Looking at the schem, it looks like that dual pot on the scehm that I looked at is dual ra but one track is 1 meg, and the other is 100k. You might have a time wit that. You may have to buy two pots and cut them apart and make one. Tayda has 100k and 1 meg dual pots that might make an interesting experiment for cut and paste! Mike. |
Mike Griffin (mgriffin155)
Username: mgriffin155
Registered: 02-2014
| Posted on Friday, February 28, 2014 - 05:01 pm: | |
Thanks Mike. I bookmarked the page. Interesting that your schematic shows 100K/1M R.A. Mine shows both being 100K R.A. I got my schematic from http://www.musicmanamps.com/schematics/2 165-rd_and_2100-rd.pdf Who knows, maybe the Gain pot isn't broken. 785K isn't that far away from 1M. I'll save this problem for when there's nothing else to do. -Mike |