Simple ADSR VST?

[luka2807]

cimoc, I am aware about the ebow, but arent we here are looking for VST alternatives?

cheers

[THK]

... of course, in this case, with this adsr vst there is no way to control the volume in real time, but thats not what I am looking for. I would be more than happy to set up adsr envelope and play my guitar like it is somekind of synth pad or violine with slow attack time.

cheers

I think you can do that with this NDC Midi ADSR.
Each point is assignable to a Midi CC, so you can increase/decrease A,D,S and R while you are playing.

[luka2807]

yea, but I do not want to fiddle with midi controllers in real time. It is not that easy to play guitar and control the adsr envelope at the same time. therefore I just want to define attack time (or any other adsr parameter) and go wild with my axe.

[SleepyP]

i can probably just throw one together in SynthEdit. it would be relatively easy to make one. i see it working like this: some sort of level-detector is used to tell the envelope "turn on". when the volume goes over a given threshold point, it sends a gate message to the envelope, equivalent to pressing a key on a MIDI keyboard. this message is held until the volume drops below the threshold point (you stop playing), at which point the gate signal ceases (equivalent to letting go of the MIDI key). the whole thing would have 1 threshold knob, 4 knobs for the ADSR envelope, and that's it. what do you guys think?

[greendoor]

Yes - I think that would work. You might need to de-glitch the 'note off' with some logic. Triggering the note-on should be a simple 'threshold exceeded'. But for the note-off, you might need to have a much lower value than the threshold, and you might need to count a few values in a minimum period to ensure that the note has actually ceased playing, and that's it not just part of the waveform. I would think the success or failure of this would depend on that. At least with midi you have a definate note-on and note-off - audio will be tricky.

[SleepyP]

while i was at work i was kicking around ideas for this, and decided i think what i'll do is make an audio/MIDI hybrid unit. the modules associated with un-used features can be made to go to sleep, thus not using any CPU unneccessarily. i was thinking that the unit could be triggered via audio OR MIDI, and the envelope's output could be used to modulate the audio output OR to output MIDI CC information (or both). this could be used as a noisegate, to add cool volume-based-envelope functionality to any MIDI controllable filter, and do other stuff. i'll work up a beta this week.

[Mokafix]

hi all,

i searched the net but didnt find something.

I need a simple ADSR (envelope) plugin which follows incoming AUDIO not midi.

thanks in advance

did you tried my "gatefish"?


it's an enveloppe/gate follower that outputs midi cc signal.
you can choose midi cc.
turning "vol adjust" to the left will make cc go down from 127, turning it right will make it go up from 0.
hmmm...
I'll do an update, cause this is not very handy...
I'll add a fifth eye, so that one eye sets start value of cc movement, and the other sets end value. it will be easier to use like that.


click my sig to go to my site.

[Mokafix]

oops, sorry, i didn't read all the posts.
seems that you are definitly not looking for midi output.

[luka2807]

Hi Sleepy,

It seems youre on the good track. One question though: What will happen with audio when level is below the treshold? Is it muted or just ignored so that output=input? I am not sure what to suggest. Maybe it would be best to leave it up to the user to decide what to do. Something like volume knob for audio that had volume below the treshold. If it is set to -oo than it acts like typical noise gate with adsr envelope.

One very important thing also:
Please make a long attack time. Something up to 2000 ms or something.

Looking forward to see how it will progress. Feel free to send me the .dll so I can betatest it.

Cheers

[greendoor]

What will happen with audio when level is below the treshold?

Since we are talking ADSR, the logical thing would be: 'A' - when triggered, the volume would ramp up at a speed set by the Attack parameter; 'D' - after the Attack, it would then Decay at a rate set by the Decay paramater; 'S' - Sustain is the period that the note remains above the trigger threshold - so this is basically the gain setting for the duration of the note; 'R' - this is the Release, once the logical 'note off' conditions are met. This basically sets how fast the gate closes. I would like to see an Inverse switch, so this ADSR gate could also be used "upside down" to put a 'notch' in some sounds, like reverb tail for example. That could give some compressor-like pumping sounds which can be very exciting.

[Mokafix]

i don't want to insist, but if you use gatefish, and choose cc# that controls volume, it would do it.
and it can do the "reverse" thing greendoor suggested, and also gate/env switch let you choose wether max "volume" is 127 or depends on audio signal volume.

[Dj mystery]

you have to trigger the adsr with midi. i tried to control a filter with an adsr and it didnt work because the audio input triggers the adsr which runs once but doesnt stop because theres nothing telling it to stop. if you have a midi note triggering the adsr while playing the audio then you can control what you like. if your trying to do it in real time then you cant unless you play the audio at the same time as triggering the midi. the other option is a gate.

[SleepyP]

silly DJ, the device hasn't been built yet, so who's to say it can't be done? i'm basically making a noisegate-style circuit control an envelope unit.
i was planning on using the standard ADSR envelope unit that comes with SynthEdit. it's got a Gate input pin, which is usually connected to a MIDI To CV unit and thus corresponds to pressing a key on a MIDI keyboard. my initial plan is to simply send the audio input to a toggle-able signal comparator device which will output the gate voltage while the incoming audio is louder than x dB (set by the user). it should be possible to set up a second unit to turn the gate voltage off once the incoming audio is below x dB. this would allow the user to set the open and close thresholds independently of one another, but may not neccessarily require its own knob. i'll see how cluttered it makes the GUI, and how consistently the unit tracks/behaves. since i haven't actually begun building it yet, i guess i'll do that now

on the behavior of the envelope itself, what exactly does an "invert" switch do?
does it simply take the controls and switch their destinations around like this:
A R
D S
S D
R R
?
i always wondered about how that was supposed to work

[greendoor]

i tried to control a filter with an adsr and it didnt work because the audio input triggers the adsr which runs once but doesnt stop because theres nothing telling it to stop.

That's exactly what i've been saying about having to use some logic to establish a "note-off" event to end the Sustain period and start the Release period. Imagine something like an electic guitar note - the initial transient would trigger the threshold for the 'Note on' - then it would settle down and gradually decay. I'm thinking you would want maybe an adjustable Release threshold, or calculate this from the trigger threshold and a "sensitivity" control. So as soon as the note decays low enough, or is actually stopped, the Release would start. This is a little different from a synth Release, where there is still an oscillator running. But it would function more like the Release of a gate or compressor.

Because a waveform cycles through zero, I think you would need to test an average of several values in a certain period of time to determin whether the note had actually dropped below the threshold, and it wasn't just the waveform it'self.

Inverse envelope - this was a wonderful feature of early Roland synths which used the same envelope for amp and filter. Inverting the envelope for filter turned a Wah into a Chew sound. I would suggest that if you had an envelope where the ADSR were related to midi CC values 0 - 127, the inverse function would simply invert each control value. A= 127-A, D=127-D, S=127-S, R=127-R.

[greendoor]

No scrub that - I think you would still use the same ADSR control values. It's the behaviour of the Amp that should change. Instead of ramping up, ramping down, sustaining and then ramping down - the inverse would in theory be ramping down, ramping up, sustaining and then ramping up. That might be interesting - sort of like an expander at the end ... maybe it would be nice to have some other options instead. Maybe the ADSR could be freely set with negative or positive values - that would be even more flexibile