Moog Music Forum

Is there a way to record changes to the filter over MIDI from a pedal plugged into the filter CV input?

For some songs I use one hand to play, one hand to tweak knobs and my foot on a Moog expression pedal to control the filter. When I record the MIDI output all the notes and manualy knob changes are recorded but the filter changes created by the pedal are not recorded. Moving the filter knob manual however is also recorded.

Is this a limitation? A bug? Or is there a setting I missed somewhere?

Thanks in advanced for any help!

I don't think it's possible with LP/SP, since those control voltages are not being digitally converted internally but are simply connected directly to the analog sections they control.

The Voyager, however, can do that if I'm not mistaken.

What you could do is play the way you normally do while recording it as a midi track. Then send the recorded midi back to the LP and record the output audio (or as midi again with overdub on) while playing with the filter knob manually... That way you would record the note on/offs, along with the knob tweaks of your other hand on the the first time around, then when you output that back to the LP, it would record the filter sweeps in addition. You have to make sure you have overdub engaged on your DAW instead of overwrite if you record the second go around as midi.


*Edited for bad penmanship

I appreciate the replies and it's a shame it doesn't work that way. I really like using the pedal as I play and can't seem to get the same sound overdubbing with manual knob movements. Sending an expression pedal through another midi controller to the little phatty just doesn't have the same granularity for the sweeps.

Would the MP-201 Multi-Pedal help me here? Would that output CV to the Little Phatty and MIDI to my DAW at the same time when the pedal is moved? Could it then play back the recorded MIDI and produce the same CV sweeps for the little phatty? I really want to be able to capture 100% of my performance digitally.

Thanks again for all the help.

My gut reaction to your MP-201 question is yes. Better wait for a user with experience to chime in or add a post to the controller section of this forum.

uftheory wrote:I really want to be able to capture 100% of my performance digitally.

I don't think MIDI is your answer because there will always be some digital "stepping" involved with a resolution of only 128 values.

The problem here is that your pedal is generating DC voltage (meaning that it is all on the positive side, from 0 volts probably up to 5v). You could try to record that as audio, however most audio hardware (computer recording interfaces included) will block DC voltage - they are only designed to record audio, which is an AC voltage (it constantly swings to both positive and negative).

There is hope though. A few computer audio interfaces will pass DC, and I think most of the MOTU units are known for doing this. MOTU also makes software called Volta that is designed to send control voltages out from your computer:
http://www.motu.com/products/software/volta
But possibly even better (and probably cheaper) there is another software package called Silent Way:
http://www.expert-sleepers.co.uk/silentway.html
Their software does a lot of stuff but one module in particular called "Silent Way CV Input" is designed to record CV signals. I think this may be your best shot at recording your pedal performance. Personally I haven't used Silent Way, but I know a lot of people use it with their modular synths and it seems to have a very good reputation amongst the community. So you might do some reading on that site and figure out what kind of interface you need to use that CV recorder.
Also, I wonder if you'd need a battery-powered pedal to record it properly, since your audio interface isn't going to provide power for a passive pedal.
Again, I've never tried such a thing, but I'm pretty sure it is possible with the right equipment.
Good luck!

The phatties and the MP-201 can operate most parameters via 14-bit midi. 16384 steps are not very noticeable. At that resolution, the scan rate of the device sending the midi message is the only source of audible stepping.

Example, my bcf2000 will send 14-bit midi, but the scan rate of the faders only permits 8-bit (256 steps) for a fast sweep to be sent. There is audible stepping there.
I am pretty sure the scan rate of the MP-201's pedal is a lot better. I think the CV is generated from the same digital scan of the pedals postion as the midi stream. I do not know if it will detect all 16384 steps for a fast sweep across the entire range.