Envelope control of delay time, has anyone tried it?

[Luke51411]

I've been curious for a while about modulation on delays and have built plenty with modulation and such. I'm planning on doing some breadboarding but I'm just curious if anyone has tried it. I haven't seen much out there for projects other than the Midfi Clari(not) maybe that does it so well people just build it? I think it would/could be cool to get a mild detune sound in the delays that is touch sensitive. Maybe it would only create crazy unusable sounds but I'm planning on trying it out, it seems like it could be cool. I'll definitely post my results here.

[StephenGiles]

Mostly crazy unusable sounds, except perhaps..................

[Mark Hammer]

Envelope control of things is not, and can not, be universal.

That is, the manner in which any given parameter is to be correlated with, or modulated by, amplitude envelope will depend on what parameter we are talking about.

So, for instance, if we're dealing with peak-limiting, you want the sidechain to have a very quick, and nearly "invisible" influence.  For modulation of filters, you may want a slightly longer attack/rise time, and a longer decay/fallback time.  Too fast, and it becomes jarring and distracting.  Too much modulation and the same thing happens.  I recall trying out different dual op-amps in a Dr. Q, and some had sweeps SO wide that the "distance" travelled seemed unreasonably fast, and just sounded bad.  Not even "neat special effect" bad, but just plain bad.  Envelope control over flanging-range delay times, as one hears in Frank Zappa or ZZ Top recordings needs to have a subtle influence, with longer time constants to get what Frank called a "pillowy" effect.

So, the question I'm asking you to consider is how much modulation, and corresponding sensitivity, would be suitable for varying delay time in the manner you are considering, and what sorts of time constants (rise and fall times) would be most suitable for what you want to modulate.  For instance, is it the sort of thing where you'd want it to be evident with each strum, or is it perhaps the sort of thing where you'd want successive pick-strokes to add more and more to a gradually-accruing envelope voltage, such that it continues to rise smoothly over a frenzy of picking, essentially "making the room get bigger as you keep playing"?

Ultimately, envelope-control over delay time is not a "bad" idea, but there will be better and worse ways of implementing it, that come closer to, or move farther away from, what feels usable and "musical" to you.

[facon]

I've used the envelope out on my Moogerfooger Low Pass to modulate the LFO speed on the delay time modulation of my Moogerfooger delay. Using an envelope to modulate LFO time for just about any effect is pretty cool. I'm not sure about direct modulation of delay time from the envelope though. I can see it being useful if you want more control to emulate tape warble or something. When I get some free time, I'll try it out and post my thoughts.

[StephenGiles]

What Mark says is absolutely correct, it would be a great effect to impress your girl friend but in a band situation - probably not worth the effort!

[Luke51411]

Thinking about it further I can see how it would be unpredictable and unmusical. I may still try it for the sake of science.

[anchovie]

I created a thing called the Noise Ensemble a few years ago, the original version is way simpler than the Clari(not) parts-wise but it is full-on fuzz all the time. Other people came up with some great mods for the circuit to make it more versatile.

http://www.diystompboxes.com/smfforum/index.php?topic=87493.0

[anotherjim]

I'm working on a delay unit at the moment, and I have given it an envelope mod. I kept it simple, just Attack and a combined Amount/Polarity added 2 pots. It acts as an offset to the manual delay control. Decay is allowed to follow the signal.

I think it's too difficult to precisely set for a stomp box, but well worth having on a desktop or rack studio unit if you have the panel space.
Chorus is it's best use I've found, as it completely removes the obvious cyclic-ness of an LFO, although I can add LFO in as well. Flanging with combined LFO and Envelope can be useful. Flanging seems nicer with cyclic sweeping, even if it's not tempo matched.

A little envelope mod can be nicely atmospheric with short feedback delay - too much and you have a Swanee Whistle, which is fun for <20seconds 

[vbrans]

Pigtronix Echolution 2 has envelope control of delay time and all other parameters separately or together.

[Mark Hammer]

I might note that many digital delay pedals will come with a "ducking" setting (perhaps calling it somethng else in some cases).  This uses envelope control to adjust how much delay is heard, such that delay is trimmed back when the signal is too busy and chock-a-block with picking/notes to have "room" for also listening to the repeats.  When the note-frenzy subsides a bit, delays are brought back in to fill in the spaces between picked notes...now that you can afford it.

Note, however, that this feature depends on the accumulated-and-averaged envelope, and not the envelope of a single strum/pluck.  This illustrates nicely the point I tried to make earlier about how the manner in which the envelope is used to control the parameter, will depend on the parameter we're talking about.

[~arph]

I've designed/breadboarded/layout a circuit that is basically a delayed effects loop. The idea was that with the loop you could in a sense simulate a bad band member doubling your sound. Only that he plays slightly after you and slightly out of tune. The delay time of the loop was settable and affected by the envelope of the input.. Worked very well. When you connect in and out of the loop you get a envelope controlled chorus effect. Sad thing is, I never built it into a pedal. I have a PCB layout ready,  but it's such a specific tool (and I don't play in bands now) that I never saw a reason to order PCBs for.