Author Topic: Best Envelope Detector circuit?  (Read 10867 times)

StephenGiles

Re: Best Envelope Detector circuit?
« Reply #20 on: September 17, 2011, 08:42:03 AM »
I should say thay it depends on the phaser. The deeper the phase, the more pronounced the envelope effect would be.
"Gods teeth", he muttered, "if these things bite one will be singing soprano".

Earthscum

Re: Best Envelope Detector circuit?
« Reply #21 on: September 17, 2011, 12:03:43 PM »
I'd think it would be more interesting to use an EF to control the RATE or DEPTH. Imagine having a phaser that gets deeper and thicker the harder you play, and the effect diminishes as your signal decays. Or a trem that goes from subtle, flowing to fast, almost BugCrusher sound.
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StephenGiles

Re: Best Envelope Detector circuit?
« Reply #22 on: September 20, 2011, 11:10:08 AM »
I'd think it would be more interesting to use an EF to control the RATE or DEPTH. Imagine having a phaser that gets deeper and thicker the harder you play, and the effect diminishes as your signal decays. Or a trem that goes from subtle, flowing to fast, almost BugCrusher sound.

There was a control circuit for just that in Craig Anderton's AMS 100 - see Device on Mark Hammer's site.

http://hammer.ampage.org/files/Device1-11.PDF
« Last Edit: September 20, 2011, 11:17:46 AM by StephenGiles »
"Gods teeth", he muttered, "if these things bite one will be singing soprano".

Mark Hammer

Re: Best Envelope Detector circuit?
« Reply #23 on: September 20, 2011, 12:10:27 PM »
That's the "Pluck follower", which requires some kind of trigger generator, which in turn requires an envelope follower of its own.

Stated more coherently, a trigger pulse is generated by each strum/pluck that generates an envelope signal of sufficient amplitude.  here's an example of such a circuit, courtesy of Jack Orman and PAiA (NOTE: it uses 748 op-amps but you can use other internally compensated types and skip the 100pf compensation caps):

The trigger pulses themselves now form the "data" that the pluck follower sums and averages out.  Think of it like a tachometer.  The more trigger pulses per unit of time, the higher the pluck-follower output goes.  Play a lotta notes and it goes higher.  Slow down your playing and it gradually decays.

A number of digital delays use a similar sort of approach, albeit with an algorithm, to adjust the level of the delay signal repeats in accordance with your playing.  This is usually listed as a "ducking" option.  If you throw a lot of notes at the delay, it backs off on the wet signal.  And when you give it some "space" to show off the repeats without creating too much audio clutter, it brings the wet signal level up again.

toneman

Re: Best Envelope Detector circuit?
« Reply #24 on: September 20, 2011, 04:21:56 PM »


just some links---

here's a 30yr old EnfFol/Trigger:

http://www.freeinfosociety.com/electronics/schemview.php?id=385


use it to control some voltage-controlled thingies...

such as an AR  (Attack/Release), ADR (AttackDecayRelease), or, ADSR (AttackDecaySustainRelease)


here's a link to a 30yr olc ADSR--

http://www.paia.com/talk/viewtopic.php?f=6&t=183

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Ice-9

Re: Best Envelope Detector circuit?
« Reply #25 on: September 20, 2011, 06:37:40 PM »
This is a good read on precision full wave rectifiers and is what i used when researching envelope followers. Figure 4 is pretty much what i got the best results from wile still keeping the circuit relatively simple. If you look closely it's pretty much the same as the above diagrams as well.

http://sound.westhost.com/appnotes/an001.htm
www.stanleyfx.co.uk

It's fairly straight forward, if you want to start it , press start. You can work out the rest of the controls for yourself !