An Envelope follower/Pitch shift resetting to sweep each repeat for delay.

[Andrew B. Campbell]

Hello everyone,

I have a project that I've devised an idea for that I'd like to apply to a dual delay utilizing PT2399's at first. I'm trying my hardest to run searches on how one might go about having a simple envelope follower trigger the sweeping of delay time with an intensity/depth of that sweep being able to be set via external knob. Each repeat would sweep and reset as it decays, both upward (shorter repeats) or downward (longer repeats) for each delay path to cause the delayed signal to only to rise or fall independently.

Here's a visual representation of what I would be trying to achieve:



If this is possible and anyone has any advice on how I might achieve this through analog means, any help would be appreciated for a step in the right direction.

[Mark Hammer]

You do realize that if you want the delay time to sweep with each new note, it will result in a radical pitch bend, right?  Or is that the purpose?

[Andrew B. Campbell]

You do realize that if you want the delay time to sweep with each new note, it will result in a radical pitch bend, right?  Or is that the purpose?

Yes, I do. That's what I'm trying to achieve. After talking to some folks, I think what I'm actually after is a dual, pitch shifting delay that would take on odd, fluttery anomalies based on what parameters were set is actually something that I'm aiming for then, yes. What inspired this was the Clarinot and No Memory delays and what auditory influences they inspired a few years back to use for this project. Then Joel released the Thermae, which seemed to be around the realm of what I had in mind, as well, but I had more in thought that I'd be implementing digitally once I began teaching myself simple forms for DSP later on to have the user unlock hidden settings within the pedal over time based on the narrative I had set for the unit. In its simplest form, I want each repeat to have a starting point and sweep up in pitch or down in pitch as they decay, return to that point immediately and repeat the process. Being a dual delay, these would each have their own toggle to allow for the repeats to sweep either upward or downward for both or opposite one another, as well as having their own decay, volume, mix and time knob. This is still in its infancy, so I'm trying to see what suggestions anyone may have to really have this project take form as it means a lot to me.

[Danich_ivanov]

From what gather, you need an envelope follower - buffered splitter after it (to isolate and split the envelope for each delay) - basic volume control for each as a sensetivity pot - and then variable resistor of you'r choise (bjt, vactrol, jfet etc.), affecting time pot. That roughly how i picture it in my head. If you're unsure about which envelope follower to use, i would recommend to start with Dr.Q, and go from there.

[Andrew B. Campbell]

From what gather, you need an envelope follower - buffered splitter after it (to isolate and split the envelope for each delay) - basic volume control for each as a sensetivity pot - and then variable resistor of you'r choise (bjt, vactrol, jfet etc.), affecting time pot. That roughly how i picture it in my head. If you're unsure about which envelope follower to use, i would recommend to start with Dr.Q, and go from there.

This makes sense. I would then want to connect have an external toggle to flit between the envelope follower sweeping up or down each delay time pot and cutting off based on the sensitivity set so that it wouldn't be a continuous over the entire delay line, but just the notes taken in. I'll have to do some experimenting, but what you described is a wonderful place to start. Thank you.

[pinkjimiphoton]

fascinating idea. sub'd

[~arph]

Sounds like an (ADSR) envelope generator and a pulse generator to trigger the envelope (ADSR) for each delay path. As long as the input envelope is above a certain value pulses are generated to trigger the ADSR's. The ADSR output is what controls the delay time.

EDIT: Or a sawtooth oscillator that is enabled/disabled depending on the input signal level.