Memorymoog "DEAD OSC" on all voice cards OSC3

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whinylittlerunt
Posts: 45
Joined: Thu Mar 16, 2006 4:30 pm

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by whinylittlerunt » Tue Dec 08, 2020 11:22 pm

Buddy...

My P28 cable was BACKWARDS :shock: :shock: :shock:

It seriously took me looking at a closeup of someone else's online to be like... wait a minute.... God, I'm an idiot.
memorymoog #1257 | minimoog model d reissue

Markyboard
Posts: 325
Joined: Wed Jul 30, 2003 6:46 pm
Location: Springfield, VA

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by Markyboard » Wed Dec 09, 2020 8:52 am

Bahh...reverse a VC P13 power cable. Then we'll talk about idiots.

https://www.youtube.com/watch?v=gsSfV4RSZ_I

whinylittlerunt
Posts: 45
Joined: Thu Mar 16, 2006 4:30 pm

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by whinylittlerunt » Sat Dec 12, 2020 3:01 am

Were you ever able to successfully do the filter tuning section of the calibration?

Image

First off, I don't have a 400F AC voltmeter, and I'm not going to get one. I had originally tried this calibration before I messed everything up and still had issues then. So based on step 8, I'm looking for 2.45V RMS which I presume I could get on my meter, right? I hooked my meter to R143 (of course, it doesn't say which SIDE of R143 to hook to although it was fairly obvious when one showed 0V). So I do exactly what it says, to adjust the emphasis trim for 2.45V rms and when I turn the trimmer, nothing happens at all. I had the strobe and my scope hooked up to it the last time I tried and I don't recall getting any reading on anything from that trimmer...

Any ideas on this one? I'm going to bet based on previous questions it's user error but, you know....
memorymoog #1257 | minimoog model d reissue

Markyboard
Posts: 325
Joined: Wed Jul 30, 2003 6:46 pm
Location: Springfield, VA

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by Markyboard » Sat Dec 12, 2020 7:36 pm

It’s been years since I’ve touched the filters. I don’t remember any specific problems but I don’t recall ever doing a full on filter cal. Only thing I can think of is make sure your octave switch is set to high.

whinylittlerunt
Posts: 45
Joined: Thu Mar 16, 2006 4:30 pm

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by whinylittlerunt » Sun Dec 13, 2020 2:18 am

My scope went bunk on me - did a factory reset on it and it came back normal. I wasn't even seeing a sinewave on that resistor until I reset it. Ended up doing the Vpp measurement since my scope had the option.
memorymoog #1257 | minimoog model d reissue

whinylittlerunt
Posts: 45
Joined: Thu Mar 16, 2006 4:30 pm

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by whinylittlerunt » Tue Dec 15, 2020 1:31 am

Tell you something....

I wish I had maybe thought about adjusting my voice card trim pots to half of their resistance before putting them in... I’ve never been so frustrated trying to range and scale an oscillator! Hours!
memorymoog #1257 | minimoog model d reissue

Markyboard
Posts: 325
Joined: Wed Jul 30, 2003 6:46 pm
Location: Springfield, VA

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by Markyboard » Tue Dec 15, 2020 6:49 am

Yeah last time I did a minor cal I "lost" one of the oscillators for a while. It is a bit frustrating. Once you find them again then it's a little bit of range a little bit of scale repeatedly until they get where they need to be. Sounds like you're almost there. Very cool.

whinylittlerunt
Posts: 45
Joined: Thu Mar 16, 2006 4:30 pm

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by whinylittlerunt » Tue Dec 15, 2020 11:28 pm

The problem I'm having now is just getting the replacement trim pots to line up in close enough range, and every time I think I have it, I don't. I've been on Voice card 2, oscillator 2 now for 2 nights. The problem is if you turn a trimmer too much, and one not enough, then you run out of turns.... :mrgreen: sucks! I got through the first voice card with very little aggravation, but this one is just killing me...
memorymoog #1257 | minimoog model d reissue

electrojoe
Posts: 40
Joined: Sun Feb 04, 2007 10:15 pm

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by electrojoe » Wed Dec 16, 2020 11:33 am

Hello,
If you tune them by ear its a lot easier.
Disable the auto tune (C-6) and enable only that voice (C-4) and tune it to a reference oscillator to start.
Adjust the scale, but don't worry about retuning the initial frequency until you have at least a decent octave range set.
Then test at 2 octaves, then re-tune the initial frequency.
Once you have it tuned by ear you can polish it off with the tune routing (c-7).

Hope that helps.

GD

whinylittlerunt
Posts: 45
Joined: Thu Mar 16, 2006 4:30 pm

Re: Memorymoog "DEAD OSC" on all voice cards OSC3

Post by whinylittlerunt » Wed Dec 16, 2020 8:05 pm

Trying to understand that but I’m not sure I follow- I had replaced every trimmer on all voice cards so naturally I expected there to be huge differences in value after they were installed. I got the first voice card in tune, didn’t take too long. Card 2 is giving me such a headache. I wonder though if I forgot to disable the autotune and maybe need to go back and check that I’m set up correctly, because I keep running off the edge aka my trimmers hit their end and can’t go any further.


EDIT: Okay, once again, I let my tired self get the best of me and I just realized I was doing it backwards... I was like, why is this taking so long?? Turns out I was using Scale for 220 and Range for 880 and it's supposed to be the other way around... works a lot faster when you adjust in the right order....

I also lost the pulse output on the 2nd oscillator of Voice 2 but that turned out to be the 4016 on that oscillator... I must have slipped with the IC clip.
memorymoog #1257 | minimoog model d reissue

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