Moog Music Forum

Yeah, I've read the service manual and the service notes. Again, and again, and again... :wink: I was hoping this was a well known issue, so I wouldn't have to source too many hard-to-get components. And the best match I've found for the FET's is Iabout $10 each. Ouch! But I guess it's not a bad thi...

Yeah, you're right, I'm just confused! The 3392 is replaced with the 3904. And you're obviously right that the transistors in question interact. This is the point were my highly limited electronics skills always fail me - I can often figure out that "this part of the circuit is an amplifier, th...

The transistors on the traces side replace the original transistors, so I don't have the originals. Q24 is replaced with a 2N3904 (originally a 2N4058). Q14 is replaced with 2N3906 (originally a 2N3392). (BTW, I got the original's values the other way around, earlier in the thread.) What's more, Q14...

Hm, I've reconnected the glide pot now and the glide is acting up. * Glide down is considerably slower than glide up. Is this by design or a problem with my mini? * If i set the glide pot to > 7, it turns into a pitch wheel... The higher I turn it, they higher the pitch. I guess the latter behavior ...

Yeah, it feels great to have gone through all this. I've recapped the PSU and rectifier boards, cleaned all edge connectors, fixed a dead headphone out, calibrated the PSU, VCO's and filter and fixed the tracking issue. And in the process, I've read the service manual and Kevin Lightners collection ...

Well, what do you know... I decided to remove the mystery mod and see what happened. I also noticed that the keyboard pitch wire going to board #2 had been cut, then soldered together again, poorly and with no insulation, so I decided to resolder it. I left the glide pot disconnected, just in order ...

:lol: Transistors soldered on the traces side of a pcb, a breadboard enclosed in a plastic bag connected to the glide pot ? Never seen a mod like that. don't know what it is. It could be a mod to get an exponential glide instead of the linear one provided originally ? I don't know. But since this c...

(Lousy joints, dirty bars, bad connections and alcohol you really shouldn't drink - restoring a mini is just a runaway spouse from being a country song, isn't it... )

If someone has simply dropped in a newer/later oscillator board to replace the original inside your Mini, without removing/disconnecting resistor R59 on switch #3 (range of oscillator 1), it may cause some pitch control issues. BTW, all Minis (so equipped) have the same buffer board though. And you...

Either that or get out the magnifying glass to look for cracked solder joints. I would first try disconnecting and reconnecting the keyboard connector (Bakelite Cinch connector notorious for oxidized aluminum pins). Accessed easily by removing the mod wheel assembly (two screws on top front). While...

Does your minimoog have the little buffer board? The early ones didn't. It's s/n 7800 so it's not very early. It's been "upgraded" with the "new" (third gen) oscillator board, but I'm not sure if they swapped to the newest buffer board at the same time. But could a faulty (or mi...

Sounds like a bad contact on one of the board connectors. Possibly pin 4 and 5 of C02 (connector of board #2). Either that or possibly a cracked solder joint on one of the connectors wires. Maybe on pin 6A of board #1 ? Or it could simply be a bad contact in the Cinch connector for the keyboard und...

:D I knew it had to be a bad contact somewhere. Maybe a cracked solder joint that got temporarily fixed by the "wiggling" technique ? :mrgreen: Quite possibly. It worries me that I don't know exactly what's the problem, or what fixed it. But I guess it's all part of the joy of vintage gea...

BTW, the keyboard was cleaned and had all bushings replaced buy the seller's tech. Feels great and is really silent. But could an error when the keyboard was reassembled account for my issue?

Well, as the subject says, if I turn filter tracking on (aka Keyboard Control), oscillator tracking turns flat, quite a bit. Keyboard Control 2 has the biggest effect, but Keyboard Control 1 contributes too. I've calibrated the PSU and the oscillators using the procedure outlined here and as long as...