ADSR VS. Envelope

gootah333

gootah333

Inspired
Looking for some insight into these two controllers, some theory and practice. I know that ADSR envelopes have a long history coming from synthesizers. I'm curious as to the trade offs and features in choosing between the ADSR and the Envelope when looking to follow the phrasing of the input.

What are there settings, if possible, for the ADSR which will make it equivalent to the Envelope? If it only comes close, what are the differences?

The ADSR has ONCE and SUSTAIN modes, which I'm thinking would be used if going for Envelope type tracking. The Envelope also has GAIN.

Mutron type sounds are of interest, but having a better understanding of how these controllers could be used would be great. Undoubtedly there are many tricks and insights on this board.
 
I am totally confused by ADSR. It would be great to have some kind of step by step examples of how to set that up for application with the Axe-II and its uses in comparison to envelope, LFO, etc.
 
With ADSR the attack/decay/release times/levels (and sustain time if sust. is disabled) are all predefined. Envelope is (or can be--high enough gain & threshold can make it a threshold-based on/off controller, which the ADSR could match) more representative of your actual input level, with the option of slowing the attack/release speed. You might get a better idea of what each param. does by assigning each controller to something obvious like a whammy control knob. Then play and note what happens to the pitch over time, and how your playing force affects that change.
 
although I don't yet have an AXE, I've looked through the manual and AXE EDIT and this is what it looks like to me...

the basic controls are
Attack - the rate at which the controlling signal is made louder
imagine using this to control the depth of a phaser.. a large A value will make the phaser effect appear to slowly increase, where as low values will make the phaser effect appear more quickly after you have struck the note

Decay is the time taken for our phaser's depth to fade to the level indicated in the Level control
a high value will mean that the sound of the phaser will peak [after the initial Attack time] and then seem to slowly fade..
a low value will me the phaser will suddenly drop to the value of the Level control

Sustain is the time to maintain the level set by the Level control.. so these parameters work together..
it 'holds' the phaser's depth for that amount of time...

when the sustain time has expired the Release time takes over and fades out the phaser...

example...
A = 100ms
D = 50ms
S = 500ms / level = 50%
R = 300 ms
the threshold setting determines at what level [the guitar's signal level] the ADSR kicks in
let's say that ours is -10dB so you have to play quite strongly to make the ADSR kick in

we attach the mix of a delay to this ADSR
the delay's mix is set to 30% so we have quite a strong delay with respect to the un-delayed guitar tone..
so on our controller we set the 'start' value to 0 and the 'end' value to 30

we play a note strongly..
the delay's 'mix' control will take 100ms to bring the delay to it's peak setting [30% wet]
then for the next 50ms the mix level will fade to the sustain level [50%] which I imagine would result in the mix level dropping to 15%..
the sustain value will hold the delay's mix level at this value for the next 500ms
the release value will then spend the next 300ms fading out the delay's wet signal to 0%

play a note softly and the ADSR will not kick in.. if the start point of the controller's 'curve' = 0 then there will be no delay...
jeez... I don't even have an AXE yet and I can see some seriously expressive uses for this already....

we set our Retrig option to on...
so if you play lots of notes in quick succession the ADSR should get to where it is in it's travel across that time line and start again
we shred... the notes are occurring in quick succession so the ADSR never makes it beyond the A=time value before it starts over..
so our shredding is pretty much delay free...
at the end of our awesome lick we hold a note we hit pretty hard and the delay rises up behind it... yummie...
and our solo softens... so we pick very softly... a strong delay would smother us.. but no.. careful threshold settings leave this delay free...
if Retrig was off, the ADSR will plough through all the time settings, doing what it has to do before looking again at the input signal to find out if it's loud enough to re-trigger it again...

the ADSR allows us to control the strength of our effects [or other parameters] via the dynamics and density of our playing.....
hmmm.... very very expressive....

the 'once' option means that the ADSR setting plays through once...
'loop' means that it cycles.. this will be therefore a variation of an LFO.. think of it like an alternate type of LFO waveform..

the sustain option keeps the ADSR at the sustain level until the guitar signal drops below the threshold level.. so it essentially over-rides the Sustain time value then the sounding note is loud enough..

this is very very powerful stuff in creative hands....
and I'm so looking forward to getting my grubby mits on it....
 
the envelope follower in the Axe is not unlike the ADSR..
but rather than setting the time values yourself, it'll match the ADSR envelope shape that's generated by your guitar [remembering that all instruments create an envelope 'shape' when they make a note sound]..
so it essentially 'chases' the guitars natural envelope.. and like the example above, you can use this to control FX parameters
the Attack setting is the time it takes to kick in
the release is the time it takes to fade out
the threshold is the same as the ADSR - how loud do you need to play before this controller starts doing it's thing..
the Gain control seems to work with [or could work against and therefore negate] the threshold control..
so balancing the gain and threshold values would be key in getting this controller to 'play nice' for you...

imagine setting this to an amp's gain...
you dig in a little harder and you get screaming high gain.. you back off and clean up...
without this controller you may find that you'd need to 'dig in' a little too strongly to get the drive you're after...
this controller could be set so your natural playing is hi gain and when you back off and play softly you clean up much more so than you would if you had the gain parameter un-controlled...
again this adds greater potential for dynamic control and expressiveness..
 
Hey Clarky,

With insight like that, you are the kind of person should have an Axe.

That is a use I hadn't thought of, something like the speed of the picking (if strong enough) could act like a ducking control.

Here's a thought: what if your ADSR was triggering the input trim of the delay, rather than the output mix? The delay could also have some regeneration, so the simple stuff
that is above the threshold gets repeated, the fast runs and quiet stuff is ignored.

I'm still not fully up to speed. Is it right that one advantage of the ADSR is to separate out the attacks of each string pluck, whereas the Envelope would "stay on longer"?
Or with the retrigger mode of the ADSR - is that same as what the Envelope always does?

Thanks Funeral for the youtube links. And Bakerman, good idea on getting bio-feedback. I really like how the Axe and Axe-Edit will show modifiers in real time on the graph. Just
wish we could lock that screen on. Does anyone know if those values are sent via CC or Sysex? ... How else would Axe-Edit know what they are?
 
gootah333 said:
Here's a thought: what if your ADSR was triggering the input trim of the delay, rather than the output mix? The delay could also have some regeneration, so the simple stuff
that is above the threshold gets repeated, the fast runs and quiet stuff is ignored.
Click to expand...
I imagine that controlling the input gain could have a generally similar but subtly different effect to controlling the mix..
maybe a more organic thing to do would be to attach the ADSR controller to both input gain and the delay's drive control [in the tone/duck page]..
this could gently fizz up the delay as you dig in more..
I imagine something like this would be more noticeable with lead tones that only have moderate amounts of gain..


gootah333 said:
Is it right that one advantage of the ADSR is to separate out the attacks of each string pluck, whereas the Envelope would "stay on longer"?
Or with the retrigger mode of the ADSR - is that same as what the Envelope always does?
Click to expand...

if the ADSR is set to 'once' then yes.. but if the ADSR is set to 'sustain' and the sustain time is long then maybe not..
I guess that the principle difference between the ADSR and the envelope follower is that with the ADSR you have more and very specific control over it's behaviour whereas the envelope follower will track the levels generated by the guitar..
so the ADSR's envelope shape is something you create yourself and as such will be a little more detached from the guitar's behaviour..
is one better than another??? not at all... they are behaviourally slightly different.. so experiment with both...
you may find the ADSR's behaviour preferable in one situation and the envelope follower is preferable in another...

these two controller types are very similar.. they're like sisters... but they are not twins...
 
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gootah333 said:
Does anyone know if those values are sent via CC or Sysex? ... How else would Axe-Edit know what they are?
Click to expand...

Nothing's sent; any movement in Axe-Edit with ADSR/envelope as source would be based on an audio input selected in MIDI settings: Monitors. It's Axe-Edit's own Envelope/ADSRs for display purposes only, responding to that input level.
 
Hah! Playing with modifiers on amp gain...Pretty fun to control it with pitch, actually! If you set it correctly you can get e.g. crunchy gain for all your chords and screaming high gain lead as soon as you play some single note lines :)
 
clarky said:
out of interest.. if the ADSR parms were externally assignable / controlable, what parm would you control and why?
Click to expand...

I think geamala means that if the ADSR´s themselves were CC triggerable and possible to setup that they would NOT follow the audio input signal, but just transmit its envelope upon a incoming CC message. You would then have a sort of "one-shot" CC modifier envelope sent out to whatever parameter you want, just by trigger it by the IA/CC switch.
So instead of having a CC switch going only ON/OFF. You would be able to have a control similar to what you can do by a expressionpedal, but it would run by itself (while you doing something else with/without your expressionpedal). The closest thing you have now in the Axe is the sequencer, not quite the same thing...

If you then on top of that also could have each parameter in the ADSR related to the local/global tempo. The ADSR´s would become a sort of 4-stage (mini)sequencers. Where you kinda decide how long and slow/fast each part will be active. I can imagine a lot of possible uses for this kind of control: i e volume/mix, wah, pitch, delay input/output level and more...

/Mike
 
I have found that when you play a lead line, the guitar signal doesn't decay very much between notes (unless perhaps you are playing slowly or very staccato). Because of that it's difficult to get an effect to retrigger on each note. It would be cool to have a controller that measures the rate of change of the input signal envelope, rather than the input signal level.
 
geamala said:
Man I god damn wish the the ADSR's were CC triggerable... that would be awesome.
Click to expand...

As an option, it would be nice to trigger the ADSR's. Having them trigger by input level would also have to be retained.

I also wish that they could be sent out as CC. This could be done for all controllers, as modified, if modifiers had an optional line for Output CC.
This could enable multi stage controller modification as well as external processing, multi media, and uber re-amping.
 
LostInSpace said:
I have found that when you play a lead line, the guitar signal doesn't decay very much between notes (unless perhaps you are playing slowly or very staccato). Because of that it's difficult to get an effect to retrigger on each note. It would be cool to have a controller that measures the rate of change of the input signal envelope, rather than the input signal level.
Click to expand...

Good point. What many of us would like at time is to have a "pick detector". I believe that the Rocktron Prophesy had it. Though i've never played one, the magic of Google just gave me this snip from their manual:

"patent-pending pluck detection"

I don't know how it is, whether the pending was denied and is moot. Of course with math, there is likely another formula to accomplish something similar. Like did anyone patent Flange, Chorus, Ducking? Hmm...

Anyway, it would be cool if we had pick/pluck as a mode for the trigger of ADSR & Envelope controllers. The Threshold could still determine cutoff. Don't know if some other parameter would be needed for pick detection. I'm thinking that the spectral content of the signal gets drastically reduced on a pluck. There is like an instantaneous mute of the string, followed be the attack. Also some level change as well. Don't think that look-ahead is needed.

I've noticed with attempts at Mutron type effects, and as many on the forum say, it is very sensitive to your guitar's volume knob and the force of your pick/pluck. So we are sort there, but as LostInSpace says, we loose it during faster runs.
 
Pretty cool stuff. I have yet to mess with any of this. Just the envelope modifier.


Sent from my iPad using Tapatalk
 
gootah333 said:
Good point. What many of us would like at time is to have a "pick detector". I believe that the Rocktron Prophesy had it. Though i've never played one, the magic of Google just gave me this snip from their manual:

"patent-pending pluck detection"

I don't know how it is, whether the pending was denied and is moot. Of course with math, there is likely another formula to accomplish something similar. Like did anyone patent Flange, Chorus, Ducking? Hmm...

Anyway, it would be cool if we had pick/pluck as a mode for the trigger of ADSR & Envelope controllers. The Threshold could still determine cutoff. Don't know if some other parameter would be needed for pick detection. I'm thinking that the spectral content of the signal gets drastically reduced on a pluck. There is like an instantaneous mute of the string, followed be the attack. Also some level change as well. Don't think that look-ahead is needed.

I've noticed with attempts at Mutron type effects, and as many on the forum say, it is very sensitive to your guitar's volume knob and the force of your pick/pluck. So we are sort there, but as LostInSpace says, we loose it during faster runs.
Click to expand...

I own a Prophesy and their claim is true; pluck-detection works great, perfect for auto WAH; I wish the AxeII had it.
 
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