Moog Prodigy: advanced reference and verification testing

(Note: What follows below is a support request and reply support e-mail sent out on the topic of the unsupported Moog Prodigy application which, though unsupported, has somehow managed to take up about 200 hours of company time in 11 years.)

hello, i recently bought a midijack (stocked in a moog prodigy), no matters what i do, transpose etc etc, my midi keyboard is never in tune with the synth
i tried calibration, transposing, sacrified a goat, nothing to do, never in tune, i read all the faq and i found a couple of thing to do, like transpose and setting up the external keyboard, but the result is pointless
any help is REALLY apprecciated, i used midijack since ever and never had a problem, just cant figured out this thing

Sorry for your troubles.

What you are experiencing is exactly why the warning mail and extra information was sent to you.

It doesn't always turn out this way, but it does sometimes.

The times it caused trouble here, the tips in the third mail (all were just sent to you a second time) solved it, although it still didn't work quite as well as, well, as well as a good synthesizer.

First, a little preliminary history is in order. Moog synthesizers do not play in tune. We have known that now for 40+ years. If they ever seem like they are playing in tune, wait five minutes, change the temperature, or just play up five octaves, and it will be totally out of tune. They have bad response, poor linearity, and a lot of drift.

Second, among Moog synths, the absolute worst is the Prodigy. In a lot of ways, it doesn't really resemble any other Moogs, and it cost 1/4th of what another Moog monosynth cost at the same time. The MG-1 is terrible, too, but in other ways, mostly due to the parts of it that just crumble and fall apart. The Prodigy doesn't fall apart so much as it is just inherently unstable. The MG-1 usually plays in tune a lot better, but nowhere near as well as an SH-101 or any ARP.

Now, if you have done all you can, you might want to seek a little point of reference. You have a fair amount of experience with MIDIJACKs I think, so you probably know how to calibrate the intonation as described in the manual. Be sure you understand it, and know that you are doing it correctly, then you can try two things:

1) Turn the MIDIJACK off so it is in bypass mode, and play your digital MIDI keyboard with one hand and the local Prodigy keyboard with the other hand. Tune them together, then play scales all over in unison. Does it play in tune perfectly all by itself? Normally, someone will say yes, but the truth is no, it does not. If it did, Moogs would not have the reputation for poor intonation that they do. If not, then it needs calibration. If you can't calibrate the Moog VCOs perfectly, that is okay, they couldn't do it at the factory, either, they are Moog synths, that's how they are. Anyway, on to the next step.

2) To get your point of reference, calibrate the MIDIJACK with a DMM. Make sure it is exactly 1.00v/octave, and tops out at 10.58v. Now, disconnect the white MIDIJACK wire and put your meter on that, and see that it is still adjusted properly. If not, adjust it while disconnected, and play all the way up, and notice that every single note is precisely in tune and no note is even 1/25th of a volt off. The output of the MIDIJACK is absolutely perfect in all cases and does not drift with temperature. This should give you a real life demonstration that the MIDIJACK is good and the synth is not. Reconnect it and see if it plays in tune, and see if the voltage is the same, or if the Prodigy is somehow loading the voltage down, or pulling it up, then engineer whatever modification you can to make the synth work properly with that perfect control voltage.

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