Mods and information on my Moog Prodigy

I bought this great little synth from eBay late in 2013. It's a MKI I believe. It was in ok condition but suffered from terrible tuning drift. This turned out to be the Negative -12 volt regulator in the power supply, an easy fix. The pots and switches were also noisy and needed a good clean. Below are some images from modding and restoration. If you only do one mod on your Prodigy, make it the FM mod.

 

BASIC RESTORE

Before the cleanup. At least there is no black foam goo like with the Rogue. All IC's were removed and gold pin IC sockets fitted. Most of the op amps were also replaced. I also do this as I find it future proofs against faults to some degree. Electrolytic capacitors were swapped for quality new replacements. All the knob tops were given a good clean with a toothbrush. The synth panel was cleaned with son of a gun car spray.

 

Something obviously spilled. Rock'n'Roll baby

 

The 'helper' AHHH

 

The fuses are a bit dangerous and the spade terminals are prone to breaking off. I superglued mine and fitted a cover to avoid accidental electric shock

MIDI INSTALL

I am just starting to mod the synth. I have started fitting a MIDI to CV converter. The push button is a midi learn button' and the switch toggles from keyboard input to MIDI control. It was quite a tricky install as I had to cut traces and lift resistors. A similar install is detailed on my Rogue page here

LFO LED

I also fitted a LFO speed indicator LED to show the rate of cycle. Handy to have. It's quite low brightness and 3mm so not too obtrusive.

FM MOD

In September 2014 I decided to try and install 'the FM mod'. This gives clangy FM type sounds to the prodigy. After hunting around the net for some time, I was unable to find any step by step guide for this. From info on the Moog forum it seems that the output of OSC 2 was fed into a potentiometer and then to the FM input. Indeed this mod may already have been semi installed on early Prodigy's, although I could be wrong about this. So I decide to use a spare 47k pot and wire the outer taps to the outer taps of the OSC2 pot. Be sure to wire these the right way round to make the sweep go from 0 to max rather than max to 0. It's an easy one to fix anyhow. The centre tap wired to the FM input. A 12mm hole was drilled and the pot mounted. It cleared the PCB nicely.

I must say this mod is well worth it and had turned my already deadly Prodigy into a sonic weapon. Below images of the wiring and the new knob on the panel. Also a quick YouTube video. I wanted to keep it as close to original. I used some letraset for the FM lettering. I also have a screaming blues distortiuon pedal in the audio path. Powerful combination.

FM mod

 

Below panel layout using an original knob cap plus a quick demo video of the new FM mod

new FM knob