1975 minimoog power supply issue
Posted: Mon Jan 06, 2020 1:33 pm
I am attempting to adjust the +10 and -10v rails on the power supply.
I get the +10 v adjusted at 10.00 v , but I can only get the -10v rail to -9.86v before the -10v pot runs out of travel..
A couple of questions, where do the +10 and -10 v sense get their voltage from? How exactly does this work, I do have a set of schematics and it seems like these lines go to the oscillator board , which I currently have removed, should I put the board back before adjust? I also saw something about disabling the sense circuits.... I'm speculating that a resistance value has probably changed in the 30+ years that this mini has been sitting. The reference 909ohm resistors seem to be precision metal film, so should be o.k. … would replacing the 10ohm adjust pot with a 50ohm pot cause any harm ? It might buy me a little more range …..
I get the +10 v adjusted at 10.00 v , but I can only get the -10v rail to -9.86v before the -10v pot runs out of travel..
A couple of questions, where do the +10 and -10 v sense get their voltage from? How exactly does this work, I do have a set of schematics and it seems like these lines go to the oscillator board , which I currently have removed, should I put the board back before adjust? I also saw something about disabling the sense circuits.... I'm speculating that a resistance value has probably changed in the 30+ years that this mini has been sitting. The reference 909ohm resistors seem to be precision metal film, so should be o.k. … would replacing the 10ohm adjust pot with a 50ohm pot cause any harm ? It might buy me a little more range …..