Prodigy/Rogue/Micro CV Modifications

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21

I don’t know how to post sounds or pictures, but I’d be happy to if you can tell me.

But the sound that will result from the mod can be very close to a ring mod type sound, like the sound of the MF102. When the resonance is down on the filter and osc 2 is being used for modulation, it gives the filter an extra burbling sound. When the resonance is high-and the filter is self oscillating- and you modulate it with osc 2, it sounds like two oscillators cross modulated, or ring modulating. This sound can be made on alot of synths such as the MicroMoog when you select osc. as the mod source and filter as the destination. But it was left off the Prodigy. So, the modification really opens up a lot of sound possibilities.

22

i don’t know how to post samples either :frowning: . are there any musicians that currently use a modded prodigy like this? is it a well-known modification? with it’s simplicity you’d think it would be…

23

This is the most common mod for the Prodigy that I’ve come across on the web. If you read back through this thread you’ll see that Till has perfomed this mod.

So, if Till could post a picture or more info, it would be great. I’m still curious about the buffer you spoke of. I don’t know if the buffer is neccesary unless you’re adding an external input?

I think the reason more people don’t do these mods as much anymore is because people don’t have experience with electronics as much as they used to. Back in the 70s, it was common for people interested in synthesizers to build their own synths from kits from Paia or EML or Aries. These synths were also closer to their modular roots, and as such encouraged users to take part in their actual design and layout. With magazines like ‘Polyphony’ that catered to this impulse, there were widely circulated instructions for all kinds of different modifications.

I wasn’t around back then, and only recently started getting interested in the idea of user modifications. I initailly started getting interested in this sort of thing just by using my Moogerfoogers and mostly I was looking to add to their flexability (but without investing in a huge expensive modular synth). So, I started doing some research on the internet and I’ve found alot of DIY sites with some useful mods here or there.

I haven’t had alot of experience with electronics myself, but I’ve learned alot already just by trying out some of what I’ve found on the internet. Even though there is always a risk of damaging your synth, I’ve found that everything I’ve done so far is quite simple and easily accomplished. Especially with American synths like Arps and Moogs there is alot of description in their user manuals that practically tells you where to insert or tap signals.

I just finished working on a bunch of modifications on my Arp Odyssey. I added direct outputs for each of the oscillator waveforms, ring mod, noise sources, LFO waveforms, envelopes, VCF, and S+H. I also inserted cv and audio inputs for the VCF, VCA, LFO trig, and Envelope trig. The Odyssey already had cv/gate and audio in/outs. So, now I’ve got a little modular synth, and it sounds like one too. I can output the oscillators to my MoogerFoogers and then send them back into the Odyssey or vice versa in every possible way.

I think the Prodigy is actually a better candidate for modifications, only I haven’t been able to find as many tested mods for it. It has great oscillators and filter but it’s very limited in the way that it’s building blocks interact. Plus, I like the idea of having a complete Moog system. With the MoogerFoogers and a Prodigy, you have nearly every every building block of a synthesizer. Only, the Prodigy needs some modifications to interact to it’s fullest potential.

24

Dear Eric (and everybody else who is interested!),

as promised, I have started to put together some info on mods I have done in the past on my Prodigy. The first results can be seen here (a friend has kindly agreed to post the info on his website since I don’t have one of my own):

http://www.javaworks.de/page13/page44/page44.html


More mods will follow, e.g. on sync-aspects, LFO-frequency range, hold-function, etc.

I hope you will find this useful. I have tried to write up some instructions which should make the mod accessible also for those with little experience in electronics.

Kind regards,

T.

25

Wow, T, you’re the man. I’m gonna go see your descriptions now.



Also, just for an example of how far user modifications can go, for anyone interested, check out this link to an MS20 re-construction project:

http://ms10rebuild.blogspot.com/


I really like what this guy did to his MS10. It’s all cosmetic, but I think it improves the synth.

26

T, I didn’t see any mods listed yet. I’m looking forward to it though…


Anybody like the MS10 Project?

27

Hello,

Eric, you may want to be a bit more strategic in how you mod your Prodigy.
I find, you don’t have to do a great deal of changes to it to significantly expand it’s capabilities. For starters, you could tailor the changes to mate the Prodigy to a Mooger CP-251. It gives the Prodigy an additional set of
modules to alter some cv functions without having to swiss cheese your synth.
The filter mod is quite useful to start with, and the ring mod tones you get from the function can be enhanced by the CP-251.
You can have a mod wheel cv out installed on the back panel, allowing you
to send the wheel cv to a multiple or the CP’s LFO pedal input. This additional lfo can be used to modulate osc 2 as audio rate modulation is
applied to the filter, producing stand-alone ring mod effects, while the
Prodigy’s internal lfo is free for vibrato.
Also useful for the stand-alone ring mod effect is a switch to disconnect the
keyboard cv from osc 2. It will function as a non-tracking modulator.
In addition, if its synced to 1, it can be used as a fixed formant.
The osc mod switch could possibly be changed to a 3-position one, like the waveform selector, allowing osc mod off/on, and an additional position if
you want modulation applied to only 1 or 2.
Just a sketch of what a match of Prodigy/CP-251 would do.
Also, while kit synths like PAIA were somewhat popular, it wasn’t a widespread practice for most to pop open their synths and mod or work on them. Some adventurous souls did so, but at the time (70’s/early 80s),
there was a cottage industry of techs/engineers who did this professionally.
Moog and Arp both had their own custom engineering groups, and also
there were third party outfits and some touring techs that specialized in this.
Wth the preeminence of OS-based synths, that industry has largely disappeared.


Regards,


Lawrence

28

Hello,

due the nice whether here and the free days I got, I am not that much online for a few days.
I will provide audio examples in the next days.
PROMISED !

But I have no electronic skills to design a right input buffer.
All I did on my Prodigy was the filter FM.
I don’t think audio-in FM on the filter is that useful to me.
But this is very much depending on style and habbits.

29

Check the Minimoog schematics for the external in preamp and the overload lamp driver. These little circuits are working so well on a Minimoog and should also work very well on a Prodigy or other synths.
Its on the same schematic’s plan as the filter. Page #72 on my Minimogg service manual. You find the scans easily on the internet.

30

Hello Eric,

in case you haven’t found the mod on

http://www.javaworks.de/page13/page44/page44.html

click on “enjoy” or on “Prodigy Mods” at the bottom end of the list on the left-hand side of the page", or go to

http://www.javaworks.de/page13/page44/page45/page45.html

I hope the desrciption and figures give some added value.

Regards form Southern Bavaria,

Tilmann

31

LWG, you’re completely right, it probably isn’t neccesary to do cut up your synths to the point where they’re unrecognizable.
But still I think some people, like me, might enjoy doing these mods and seeing if they can customize or improve the functions of exsisting synths. I also kind of feel that these instruments shouldn’t neccesarily be thought of as untouchable works of timelessness.
I feel more endeared to a synth that I’ve customized in some way, and theres also a kind of satisfaction that comes from actively participating in the design or redesign of a synth to fit one’s own needs. I don’t have any backgound in electronics, and I’ve been able add to the functionality of the instruments I use with very simple operations.
So, if there are easily repeatable proceedures for untrained people who might not otherwise consider attempting this sort of thing, I feel it’s worth diseminating.

For some reason, I didn’t find the link the first time Dr.T, but I’m looking forward to cheching it out now. Thanks again.

32

Here is a quick example of the easy to do Filter-FM modulation for Moog Prodigies:
http://www.till-kopper.de/Moog_Prodigy_FM_demo.mp3 (721 kB, 128 kbps, mono).
First no FM self oscillating filter.
Then a bit FM applied.
Plenty FM applied and the cut-off moved.
At 0:17 the oscillators are faded in.
0:31 LFO applied to the oscillators. And therefor the oscillator 2 is FM-ed and modulating the filter. This is 3 OP DX like FM :wink:
The last seconds are without FM again.

33

For info: Matthias just posted my next contribution to the collection of mods for the Prodigy; see:

http://www.javaworks.de/page13/page44/page46/page46.html

This one is a switchable range-extension of the LFO frequency.

Hope it’s of use!

Regards from very hot Southern Bavaria,

T.

34

Thanks T, these mods look very useful and are helping to give me more ideas on some mods I’m planning. This documentation is great.

35

And another mod for the Prodigy - this time it’s a VCA-hold function:

http://www.javaworks.de/page13/page44/page47/page47.html

I hope it’s of use - but then there’s more to come …

Regards,

T.

36

Hi T. :slight_smile:

I got this mod here too. It was very easy to discover this mod:
just set the DECAY switch somewhat between the on and off position and you got a hold function.
I used this mod for drone notes in my early days of EM 24 years ago.

37

That is a really interesting remark! I wasn’t aware of this possibility … which will work only if the mechanical arrangement of the individual switch will allow for it!

I love things like that! These hardware quirks work only with old analog gear … this specific example is a bit similar to finding the “in-between” pickup-switch position on old Stratocasters which have the original 3-position switch!

Great input, Till - thanks