Modifications and Enhancements
Control Voltage Modulation and Sync
No complicated mods here... Just an interesting combination of midi to CV converters, analog modules, and a few tricks that have yielded some neat capabilities. For space and money reasons I don't foresee ever owning a full MOTM style modular synthesizer, but I do want to be able to incorporate some of their CV modulating abilities into my analog synth setup. Here are a few tools I have put together to sync and modulate my analog gear with audio and modern digital info.
The Baja box : This is simply a few analog modules housed in a modified old tweed Baja visual slide storage box. The modules include the Doepfer A-170 Dual Slew Limiter, the Doepfer A-119 External input / envelope follower, an MFB DRUM 04 808 bass drum module and a Doepfer A-100 miniature power supply. It has room and power for another module one day....
The A-170 is called a "slew limiter", but I think that it is more descriptive to use the term portamento. Essentially it gives you control of the speed and smoothness of the transition between CV voltage changes. This allows you to add portamento to any CV controlled synth, create modulating CV signals that flow in sync with note changes and anything else you can imagine. I originally used it to help smooth out the note sliding transitions of my midi ribbon controller.
I basically only use the A-119 module to turn audio into a CV signal which is a pretty nice tool. For instance you could sync some synth or effects modulation to a drum beat or instrument section. One neat trick is to send your kick drum audio track into it and use the CV output to trigger an analog kick drum like the MFB 04 for layering or replacement of the kick sound. The DRUM 04 is a great sounding 808 style kick module. The MFB 04 also has a ton of CV controlled variables that can be fun to sync to audio with the A-119.
Various Moogerfooger Pedals : 12 Stage Phaser, Ring Mod and Lowpass Filter. Along with their extremely flexible sonic uses they can also help tweak and shape CV signals as well as be synced to my DAW and other gear using CV.
Moogerfooger CP-251 : This is a pretty darn powerful tool for CV modulation, but that is all it does. All of the CV patching can get confusing, so I color coded and numbered my patch cords to help keep track of my cv routings. There is plenty of info on the web on this thing already, so no need to run through the specs here. Between this thing, my Baja box and my Moogerfooger pedals, I can come close enough to a modular synthesizer's CV capabilities to keep myself from lusting after one.
Photosensitive CV Controller : These are simple boxes with a photosensitive resistor to control the CV voltage. They small and allow you to tweak several settings at once, however they do not allow you to set a default voltage or a voltage range so they are strictly for experimental sound tweaking. They can be used with strobe lights or as foot or hand controls by blocking out the light. Ambient light is too difficult to control to accurately recreate a performance under different conditions. I added a laptop led light to my guitar pedalboard above my moogerfoogers to provide more light to the sensors. I also added metal base that could be mounted to a moogerfooger pedal and a hinged cover to minimize the cv level when closed.
Kenton Pro Solo MkII : A midi to CV converter that allows me to control notes and modulation for analog synths, effects pedals and drum machines via midi controllers, and through my DAW recording software. This enables me to sequence my analog gear and also tempo sync effects and LFO modulating signals to my songs. Although it seems like midi to Control Voltage converters would be quite simple to make and in demand given the obession with analog synths these days... The options are few, limited and expensive. This was a lucky eBay find.
