I have both a micro and a multi, when I plug in the moog expression pedal into any of the cv inputs nothing happens. I want to be able to control the cutoff on either one via expression pedal, but it doesnt seem to work at all on either synth in any of the cv inputs/outputs. Any reccomendations or will this not even work?
expression pedals are normally made to receive a +5 V voltage and attenuate it and feed the lowered voltage back to the synth to make some changes. It uses steareo plugs.
A CV input is always a pure voltage input. So you have to provide the voltage. And most CV in and outputs are using monophonic plugs. Some synths used a stereo socket to provide CV in and out put in a single (= cheaper) socket.
So you have to use an active expression pedal with batteries inside.
Or you have to modify an existing passive expression pedal to deliver the voltage that is attenuated and then feed in the Moog.
Most nowadays keyboard have expression pedal ins, but not real pure CV ins. That is why you don’t find active pedals at the music shop in your town.
You can make an active voltage pedal by connecting a 9 volt battery to the input of a passive volume pedal. The red wire of the battery clip goes to the tip, the black wire goes to the sleeve.
Then the output will be 0-9volts, which will be suficient.
You can buy various commercial voltage pedals (mostly from the 70s, some from the 80s) but they are usually expensive–due to the fact that they are no longer being manufatured. Voltage Control was an obsolete standard for many years and is only recently starting to be used again–with the resurgence of interest in Modular Synthesis.
The Yamaha FC9 is still available 
i actually think im gonna buy this:
http://www.rhodeselectrics.com/korgcvpedal.htm
It looks really sturdy compared to all the plastic ones out there, and that LFO feature is pretty awesome too.
boss fv-series and yamaha fc are an option.
but this “korg” one is nice!
Yes! This is perfect. Very similar to the Korg MS03-- which sometimes sells for as much as $300-$500 because of it’s rarity. I was fortunate to find one of these korg pedals for use with my Ms20 for a good price (maybe $50) but when they rarely come up on e-bay, they typically sell at ridiculous prices.
So, it’s cool that someone is now making a nice, sturdy alternative.
It’s a little high-- 99 euros is like $150, I think? But it looks nice.
I think the Boss FV-500 series is about the beefiest one out there. I just love mine. It comes in a high-impedance model or a low-impedance with stereo ins/outs. Either way, its totally worth the $.
Boss fv500 is €89,-and has expr. output, but no LFO!
One more question about this, I will have to connect a cable from the pedal to the synth, can I use a regular instrument cable or will it have to be TRS?