Envelope to CV/Expression Pedals?

[Dandolin]

[qersty]

you may want to try this setup for better response from the volume knob

[Tall Walls]

I've been kind of fixated on this concept for a while, despite having found very few applications that sound good or interesting. Filter stuff always works, of course, but so many other effects are either vanishingly subtle (modulation speed, say) or obnoxiously unsubtle (pitch, usually). I was sure having envelope control over Generation Loss parameters with the Arcades pedal would be totally sweet, but it has not proven to be so. Maybe a little sweet. My favorite application is having the envelope change the delay time on the Time Bender just a tiny bit. If you hold a loop and then play over it, the longer you play the more degraded the loop gets. I apologize for having no potato jokes.

[qersty]

obnoxiously unsubtle (pitch, usually)

Envelope controlled pitch mod is the best. How are you doing it? I find it very easy to get tasty with it

[oldangelmidnight]

My classic favorite was to use envelope to control the speed of a tremolo.
I like using envelope to control parameters on Count to Five but I'm not afraid of unsubtlety.

[Tall Walls]

Envelope controlled pitch mod is the best. How are you doing it? I find it very easy to get tasty with it

Poorly? It's been a while. I just remember trying the Copilot Autodialer on everything with an expression port and having a hard time with pitch effects. I was probably using the Behringer pitch shifter. I think I was suffering from knob-tweaker's fatigue, trying to get something other than a wild sproinging sound and eventually giving up.

[oldangelmidnight]

Might as well get a PLL.

[Dandolin]

my interest in envelope tweakage, beyond filters, is headed up and followed up by carrier freq for balanced mod

[mcatano]

There's a schematic in the Anderton book for an envelope follower:


If you know anyone who's handy with stripboard they could whip one together for you.

[Dandolin]

[Schlatte]

This might be a stupid question, but why not just grab a Copilot Autodialer for a 100 bucks from reverb and have basically achieved exactly what you want?

[Schlatte]

There's a schematic in the Anderton book for an envelope follower:


If you know anyone who's handy with stripboard they could whip one together for you.

That circuit would need to be modified for your application - to control an EXP/CV in you need a voltage divider, not just a variable resistance. So either add a suitable pullup/pulldown resistor on one of the optoisolators to form a voltage divider and mimic an expression pedal or use a different circuit. Additionally, here you need bipolar supplies (+/-9V), optoisolators, etc. - I think this can be achieved easier, especially if you're going for CV out instead of real EXP control - what exactly do you need? EXP or CV?

An Envelope Follower is basically just a rectifier with a buffer cap and a discharge resistor. To have a really accurate envelope tracking, you would have to go digital, for simple stuff the analog designs will suffice. If you only need CV out (0-5V) that could be achieved with a quite simple OpAmp circuit.
If you want true EXP Pedal output, it would probably be best to go digital and have a microcontroller sample the signal for the envelope and control a digital potentiometer to use as EXP out.

[Dandolin]

thanks for that input

[Dandolin]

another idea i have for envelope control (with some input from lordgalvar) - for pedals that have expression control over mix, say a Belton Brick reverb or an analog or PT2399 delay (not saying any exist right now, but just for instance), use that mix control input with the envelope output to do quasi-ducking type things, or fade in the decay on the Belton Brick to bypass that slapbackish onset that some find annoying, or create a quasi-gated response, etc.

a super subtle use would be to increase/decrease the feedback/intensity of a flanger/phaser/srr type pedal....

I have a custom Stomping Stones Virus with expression control over input gain that does some really interesting whooshy stuff when I wiggle it, and I'm definitely intersted in seeing what happens with enveloe control. Also, I have a long term interest in externally controlling bias on fuzz for texture/movement, and I maintain an interest in seeing how envelope control of bias might translate - pretty subtle, I'd warrant, but I also have expression controllable voltage starve, blend, crossover, pan pedals - all possible hits?

also - ideally with this kind of pedal, you could invert the response output for different purposes (not saying that would be easy to accomplish, just could be useful)....

[Dandolin]

Well! It's a funny world, but I've now received an unexpected package from Copilot with a custom Autodialer I honestly didn't expect to see, so I will definitely be exploring that - but thanks to all for the ideas and encouragement - it's cool to know about other options, and I hope to see more choice in this little corner of effectdom in future