Leprechaun CV instead of expression pedal

[Riccardo Turacchio]

Hi folks I'm building a leprechaun and I was thinking of installing the jack for the expression pedal
But I will use mostly my Beatstep sequencer or LFOs so it's Control voltage and normally is just a mono mini jack,
My question is...can I just use a switched mono instead of stereo?...

 

[Robert]

That should work but keep in mind the FV-1 is a 3.3V device, it won't last very long if you hit it with a 5V CV.

 

[pricklyrobot]

If you’ve got a modular synth, the safe easy way to do this is:
• build the pedal with the normal TRS jack
• get a TRS-to-dual TS splitter cable, and patch to the In and Out of a VCA module
• use your CVs (Beatstep, LFO, etc.) to modulate the VCA

This way the pedal can only get back a modulated version of whatever voltage it’s putting out itself. No danger of cooking the FV-1.

 

[Riccardo Turacchio]

That should work but keep in mind the FV-1 is a 3.3V device, it won't last very long if you hit it with a 5V CV.

What if I use something like this

 

[Riccardo Turacchio]

R1 10k R2 20k ?

 

[Riccardo Turacchio]

...and eventually also an attenuator pot ...??

 

[giovanni]

I think the voltage divider may work but you really need to make sure what the CV range is. Some CVs give way over 5V. Some go negative even.

 

[Riccardo Turacchio]

I will check the Beatstep CV output with a multimeter but pretty sure it won't go negative...
Maybe also include a diode at this point...just for extra safety

 

[giovanni]

OK, I wanted to double check and I found this post where they suggest using a pot to make a CV attenuator. I think adding a 3.3V diode would probably give you an extra peace of mind.

 

[tegendemuur]

I'd go for / build something external. This way you can use CV on all the other things that have EXP that you already got laying around.

There aught to be a DIY projects similar to things like this:

Copilot Fx Broadband expression pedal splitter

 

[pricklyrobot]

Here’s a CV-able, DC-coupled dual VCA in pedal format (runs off a standard 9V center-neg supply, too) :
https://www.hungryrobotpedals.com/vca

Can’t vouch for it personally, but it looks very handy, and the price isn’t bad.