MOTM

I'd like to see the envelope follower this year and of course, the 
130(?) dual vca/panner.

Also, why isn't the 910 available as a kit?

>After that, I guess JH, Crow and I will have to cook up some new
>stuff for the remainder of the year. SEM filter, anybody? :)
>
> Paul S.

It may be a ways off, but there is a MOTM Envelope Follower in our future,
yes?  I did some searching of the archives to see if I could determine any
info on this "elusive" device. :)  Not much luck, I'm afraid.  All I could
find was, that Paul indicated he was either going to go with a more
"standard" design, or a totally "over-the-top" design.  I sure what ever he
chooses, it will kick a@@.  In any case, I am wondering, what functions
should this module include?

Obvious features would include rudimentary preamp, signal input, input gain,
gate output, gate threshold control, response time control, envelope out and
envelope level.

Some addl. potential features might be:
mic vs line level input
separate attack and decay response settings
trigger out
gate led
clip led
preamp out
FWR out
peak-correction circuitry (to enhance performance for even-harmonic signals)
multiple FWR/peak-correction AC-coupled stages

Any thoughts out there?

George

It seems to me I read something once about using multiple FWRs as
frequency doublers in envelope followers.  This is supposed to improve
the response time.  I may have read this somewhere in ElectroNotes, I'm
not sure.  I'm out of town at the present time and unable to verify the
source.  It might be interesting to have outputs from multiple FWRs on a
module such as this.

-----Original Message-----
From: groovyshaman@... [mailto:groovyshaman@...] 
Sent: Saturday, July 19, 2003 7:29 PM
To: motm group
Subject: [motm] Envelope Follower


It may be a ways off, but there is a MOTM Envelope Follower in our
future, yes?  I did some searching of the archives to see if I could
determine any info on this "elusive" device. :)  Not much luck, I'm
afraid.  All I could find was, that Paul indicated he was either going
to go with a more "standard" design, or a totally "over-the-top" design.
I sure what ever he chooses, it will kick a@@.  In any case, I am
wondering, what functions should this module include?

Obvious features would include rudimentary preamp, signal input, input
gain, gate output, gate threshold control, response time control,
envelope out and envelope level.

Some addl. potential features might be:
mic vs line level input
separate attack and decay response settings
trigger out
gate led
clip led
preamp out
FWR out
peak-correction circuitry (to enhance performance for even-harmonic
signals) multiple FWR/peak-correction AC-coupled stages

Any thoughts out there?

George



 

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Paul Haneberg wrote:
> It seems to me I read something once about using multiple FWRs as
> frequency doublers in envelope followers.  This is supposed to improve
> the response time.  I may have read this somewhere in ElectroNotes, I'm
> not sure.  I'm out of town at the present time and unable to verify the
> source.  It might be interesting to have outputs from multiple FWRs on a
> module such as this.

Yes, this is my understanding.  And yes, Electronotes #60, #86, #88 & #89 -
good memory!  There is a trade off when determining the time constant of the
filter between being able to detect snappy envelopes and reducing the amount
of voltage ripple on the detected envelope for lower frequencies.  Obviously
fast envelopes at low frequencies is the biggest problem.

So by adding say two additional FWR sections, this would quadruple the
frequency of the signal (in theory) thereby allowing the low-pass filter
cutoff frequency to be increased, which in turn improves the speed (response
time) of the envelope detection.  From what I understand however, FWR does
not work properly for sine waves (or other predominantly even-harmonic
waveforms), as the subsequent waveforms are not symmetrical about the x axis
and do not frequency double.  An AC-coupled peak-correction circuit can be
used in conjunction with each FWR section, to add in the appropriate amt of
offset voltage to the FWR section to make up for the non-symmetry in the
waveform.  (I think I've got that right :)

Anyway, I have yet another crazy feature that may be nice.  I think I
remember reading about it somewhere, the MAM filter or something?  Have
three envelope follower sections, each tracking a separate frequency range,
say low, mid and high.  Then the envelope output of each of those could be
sent to the three inputs on the OMS-410 filter companion module.  Woah -
sounds like fun!

One more thought (like beads of water on the forehead, eh? :) .. until a
MOTM equivalent is available, if one has a Wavefolder and a MOTM-820, a
simple envelope follower could be patched up.

Cheers,
George

Another interesting implementation (especially for guitarists) is from  
an article by Harry Bissell:

http://go.cadwire.net/?3572,3,1

It uses three peak detectors which are continuously reset. I did a  
digital implementation as a Mac Audio Unit, and the responsiveness for  
guitar is quite nice.

I don't have the wavefolder, but I patched up a rudimentary EF by  
sending an amplified guitar signal to both inputs of the 110 ring mod  
followed by an 820. Lot's of ripple but still fun.

Tomy

On Saturday, July 19, 2003, at 07:53 PM, groovyshaman@... wrote:

> Paul Haneberg wrote:
>> It seems to me I read something once about using multiple FWRs as
>> frequency doublers in envelope followers.  This is supposed to improve
>> the response time.  I may have read this somewhere in ElectroNotes,  
>> I'm
>> not sure.  I'm out of town at the present time and unable to verify  
>> the
>> source.  It might be interesting to have outputs from multiple FWRs  
>> on a
>> module such as this.
>
> Yes, this is my understanding.  And yes, Electronotes #60, #86, #88 &  
> #89 -
> good memory!  There is a trade off when determining the time constant  
> of the
> filter between being able to detect snappy envelopes and reducing the  
> amount
> of voltage ripple on the detected envelope for lower frequencies.   
> Obviously
> fast envelopes at low frequencies is the biggest problem.
>
> So by adding say two additional FWR sections, this would quadruple the
> frequency of the signal (in theory) thereby allowing the low-pass  
> filter
> cutoff frequency to be increased, which in turn improves the speed  
> (response
> time) of the envelope detection.  From what I understand however, FWR  
> does
> not work properly for sine waves (or other predominantly even-harmonic
> waveforms), as the subsequent waveforms are not symmetrical about the  
> x axis
> and do not frequency double.  An AC-coupled peak-correction circuit  
> can be
> used in conjunction with each FWR section, to add in the appropriate  
> amt of
> offset voltage to the FWR section to make up for the non-symmetry in  
> the
> waveform.  (I think I've got that right :)
>
> Anyway, I have yet another crazy feature that may be nice.  I think I
> remember reading about it somewhere, the MAM filter or something?  Have
> three envelope follower sections, each tracking a separate frequency  
> range,
> say low, mid and high.  Then the envelope output of each of those  
> could be
> sent to the three inputs on the OMS-410 filter companion module.  Woah  
> -
> sounds like fun!
>
> One more thought (like beads of water on the forehead, eh? :) .. until  
> a
> MOTM equivalent is available, if one has a Wavefolder and a MOTM-820, a
> simple envelope follower could be patched up.
>
> Cheers,
> George
>
>
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>

Don't laugh, but one of my favorite envelope followers of all time 
was the PAIA design. At certain settings it was a rather accurate 
pitch follower. It was also excellent for processing audio. I used it 
for very convincing thunder and for a a cello sound that would almost 
shame Elhardt.

Sometimes simpler is better.


johnm

Johnm writes:
>>Don't laugh, but one of my favorite envelope followers of all time was the 
PAIA design. At certain settings it was a rather accurate pitch follower. It 
was also excellent for processing audio. I used it for very convincing thunder 
and for a a cello sound that would almost shame Elhardt....Sometimes simpler is 
better.<<

Such a ridiculous and physically impossible statement.  There isn't anything 
about an envelope follower or its filtering capability that comes close to the 
kind of complex freq response and sound I get from the processing I do. And 
it's only going to get more complex when I upgrade the OS.  Simpler is only 
better for simple sounds.

When I first got my Multimoog, I used to think I got a decent cello sound from 
it when I played it through a Leslie speaker and used my right hand on the 
ribbon controller to give it manual vibrato much like a real string player. I'm 
sure if I heard it today it wouldn't sound very good.  Memory has a way of 
altering the past.

-Elhardt

Elhardt wrote:

>Such a ridiculous and physically impossible statement. There isn't 
anything 
about an envelope follower or its filtering capability that comes 
close to the 
kind of complex freq response and sound I get from the processing I 
do.<

Thank you for the humble reply, but a synthesist of your caliber must 
know that sometimes extremely simple patches yield extremely complex 
results. Please note that I said the sound would *almost* shame your 
cello. But that ain't bad, given that it didn't require 100 digital 
filters.

I might have mentioned the patch in a (not very good) Polyphony 
article called "The Sensuous Envelope Follower."

As I recall, the cello sound used a pulse wave (going from spikey to 
fat), modulated by an ADSR.  When pulse waves start out very skinny, 
they look like DC to the envelope follower because the spikes are 
filtered out.  The PAIA design couldn't pass DC, so the sound would 
start at zero, then become fuller. Complex stuff happened as this 
transition occurred that gave a wonderful "bowing" effect--and the 
timbre was just right.  Mind you, the effect was good only over an 
octave or so, but it was very convincing.

johnm

Konkuro writes:
>>Thank you for the humble reply, but a synthesist of your caliber must know 
that sometimes extremely simple patches yield extremely complex results. Please 
note that I said the sound would *almost* shame your cello. But that ain't bad, 
given that it didn't require 100 digital filters.<<

Actually to say that something almost shames something else is to imply that it 
is so much better that it would almost cause shame to the other.  Knowing that 
an envelope follower set to the point where it might pass sound through it, 
means it's probably nothing more than a full wave rectifier.  And that hardly 
compares to the "100 digital filters" thing.  Afterall, if it were that simple, 
MoogCE wouldn't be selling $1500 36 band string filters, but $20 rectifiers 
instead.

And sure I know that simple patches can yield complex results (not for complex 
wooden body resonance though).  I had a couple of people on the Nord list 
amazingly wonder how I could have done that complex sounding piano slam patch.  
After posting the patch it almost seemed as if one guy was disappointed at how 
simple it was.

-Elhardt

hello,

isn't it possible to use the lag processor as an enveloppe follower 
(with up-pot set to minimum and down-pot set to slew so it 'rides' 
the enveloppe?)

greetz,
chef!

Yes, this will work to a limited extent.  Up control should be at or
near zero and Down control should be about 5.

Ideally you would precede this with a full wave rectifier.  My DIY Diode
Waveform shaper module can do that, information located here:
http://www.wavemakers-synth.com/motm/dws.html .  Nothing immediately
comes to mind for accomplishing this with just MOTM modules, but somehow
I feel an MOTM-800 Dual VC Router patch coming on. :-)

John Loffink
jloffink@... 

The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com/

The Wavemakers Modular and Integrated Synthesizer Web Site
http://www.wavemakers-synth.com/

> hello,
> 
> isn't it possible to use the lag processor as an enveloppe follower
> (with up-pot set to minimum and down-pot set to slew so it 'rides'
> the enveloppe?)
> 
> greetz,
> chef!
> 
>

And if you have Tony's WaveFolder, that'll do the trick, too...

--- In motm@yahoogroups.com, "John Loffink" <jloffink@a...> wrote:
> Yes, this will work to a limited extent.  Up control should be at 
or
> near zero and Down control should be about 5.
> 
> Ideally you would precede this with a full wave rectifier.  My DIY 
Diode
> Waveform shaper module can do that, information located here:
> http://www.wavemakers-synth.com/motm/dws.html .  Nothing 
immediately
> comes to mind for accomplishing this with just MOTM modules, but 
somehow
> I feel an MOTM-800 Dual VC Router patch coming on. :-)
> 
> John Loffink
> jloffink@a... 
> 
> The Microtonal Synthesis Web Site
> http://www.microtonal-synthesis.com/
> 
> The Wavemakers Modular and Integrated Synthesizer Web Site
> http://www.wavemakers-synth.com/
> 
> > hello,
> > 
> > isn't it possible to use the lag processor as an enveloppe 
follower
> > (with up-pot set to minimum and down-pot set to slew so 
it 'rides'

> > the enveloppe?)
> > 
> > greetz,
> > chef!
> > 
> >

That should be MOTM-700 Dual VC Router.

John Loffink
jloffink@... 

The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com/

The Wavemakers Modular and Integrated Synthesizer Web Site
http://www.wavemakers-synth.com/

> -----Original Message-----
> From: John Loffink [mailto:jloffink@...]
> Sent: Sunday, July 27, 2003 12:08 PM
> To: 'grotechef'; motm@yahoogroups.com
> Subject: RE: [motm] Re: Envelope Follower
> 
> Yes, this will work to a limited extent.  Up control should be at or
> near zero and Down control should be about 5.
> 
> Ideally you would precede this with a full wave rectifier.  My DIY
Diode
> Waveform shaper module can do that, information located here:
> http://www.wavemakers-synth.com/motm/dws.html .  Nothing immediately
> comes to mind for accomplishing this with just MOTM modules, but
somehow
> I feel an MOTM-800 Dual VC Router patch coming on. :-)
> 
> John Loffink
> jloffink@...
> 
> The Microtonal Synthesis Web Site
> http://www.microtonal-synthesis.com/
> 
> The Wavemakers Modular and Integrated Synthesizer Web Site
> http://www.wavemakers-synth.com/
> 
> > hello,
> >
> > isn't it possible to use the lag processor as an enveloppe follower
> > (with up-pot set to minimum and down-pot set to slew so it 'rides'
> > the enveloppe?)
> >
> > greetz,
> > chef!
> >
> >
> 
> 
> 
> ------------------------ Yahoo! Groups Sponsor
> 
> 
> 
> Your use of Yahoo! Groups is subject to
http://docs.yahoo.com/info/terms/
>

I could not get my Oakley Wavefolder to do the full wave rectification
by itself.  You would have to take the clamp and clip outputs and mix
them together, which indeed is another solution to the problem.

John Loffink
jloffink@... 

The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com/

The Wavemakers Modular and Integrated Synthesizer Web Site
http://www.wavemakers-synth.com/

> And if you have Tony's WaveFolder, that'll do the trick, too...
> 
> --- In motm@yahoogroups.com, "John Loffink" <jloffink@a...> wrote:
> > Yes, this will work to a limited extent.  Up control should be at
> or
> > near zero and Down control should be about 5.
> >
> > Ideally you would precede this with a full wave rectifier.  My DIY
> Diode
> > Waveform shaper module can do that, information located here:
> > http://www.wavemakers-synth.com/motm/dws.html .  Nothing
> immediately
> > comes to mind for accomplishing this with just MOTM modules, but
> somehow
> > I feel an MOTM-800 Dual VC Router patch coming on. :-)

hello john,

excuse my ignorance - why would i want to full wave rectify the 
signal before inputting it to the lag processor?

thanks for your feedback!

greetings,
chef!

> you would precede this with a full wave rectifier.

FWIW, the Synthesizers.com Q130 Clipper module has a FWR section on 
it. Should work just fine with MOTM.

johnm

> I could not get my Oakley Wavefolder to do the full wave rectification
by itself.

Try setting the WF to the following:

Gain set to around 2 o'clock.
Threshold set to mid point.
Fold set to around 10 o'clock.
Output to full.

Output signal taken from main output. Clamp polarity will set the
polarity of the output. Lower will give you positive only signals.

This will also act as octave doubler for triangle waves.

Tony

Yep, works for me.  COnfirmed it with a scope, too.

--- In motm@yahoogroups.com, "Oakley Sound" <oakley@t...> wrote:
> > I could not get my Oakley Wavefolder to do the full wave 
rectification

> by itself.
> 
> Try setting the WF to the following:
> 
> Gain set to around 2 o'clock.
> Threshold set to mid point.
> Fold set to around 10 o'clock.
> Output to full.
> 
> Output signal taken from main output. Clamp polarity will set the
> polarity of the output. Lower will give you positive only signals.
> 
> This will also act as octave doubler for triangle waves.
> 
> Tony

Okay, I finally had a chance to try this out.  I don't know why I
couldn't get this before.  However, my settings are more like Gain at 10
o'clock and Fold almost to 11 o'clock. 

John Loffink
jloffink@... 

The Microtonal Synthesis Web Site
http://www.microtonal-synthesis.com/

The Wavemakers Modular and Integrated Synthesizer Web Site
http://www.wavemakers-synth.com/

> Yep, works for me.  COnfirmed it with a scope, too.
> 
> --- In motm@yahoogroups.com, "Oakley Sound" <oakley@t...> wrote:
> > > I could not get my Oakley Wavefolder to do the full wave
> rectification
> > by itself.
> >
> > Try setting the WF to the following:
> >
> > Gain set to around 2 o'clock.
> > Threshold set to mid point.
> > Fold set to around 10 o'clock.
> > Output to full.
> >
> > Output signal taken from main output. Clamp polarity will set the
> > polarity of the output. Lower will give you positive only signals.
> >
> > This will also act as octave doubler for triangle waves.
> >
> > Tony
> 
>

Yes, my settings were not exactly TOny's either.  Damn this analog 
imprecision!  But I do have a question: is the gain there 
to 'saquare off' the waveform?

Mike

--- In motm@yahoogroups.com, "John Loffink" <jloffink@a...> wrote:
> Okay, I finally had a chance to try this out.  I don't know why I
> couldn't get this before.  However, my settings are more like Gain 
at 10
> o'clock and Fold almost to 11 o'clock. 
> 
> John Loffink
> jloffink@a... 
> 
> The Microtonal Synthesis Web Site
> http://www.microtonal-synthesis.com/
> 
> The Wavemakers Modular and Integrated Synthesizer Web Site
> http://www.wavemakers-synth.com/
> > Yep, works for me.  COnfirmed it with a scope, too.
> > 
> > --- In motm@yahoogroups.com, "Oakley Sound" <oakley@t...> wrote:
> > > > I could not get my Oakley Wavefolder to do the full wave
> > rectification
> > > by itself.
> > >
> > > Try setting the WF to the following:
> > >
> > > Gain set to around 2 o'clock.
> > > Threshold set to mid point.
> > > Fold set to around 10 o'clock.
> > > Output to full.
> > >
> > > Output signal taken from main output. Clamp polarity will set 
the
> > > polarity of the output. Lower will give you positive only 
signals.

> > >
> > > This will also act as octave doubler for triangle waves.
> > >
> > > Tony
> > 
> >

Or more precisely 'square off'...sheesh

--- In motm@yahoogroups.com, "Mike Marsh" <mmarsh@w...> wrote:
> Yes, my settings were not exactly TOny's either.  Damn this analog 
> imprecision!  But I do have a question: is the gain there 
> to 'saquare off' the waveform?
> 
> Mike
> 
> --- In motm@yahoogroups.com, "John Loffink" <jloffink@a...> wrote:
> > Okay, I finally had a chance to try this out.  I don't know why I
> > couldn't get this before.  However, my settings are more like 
Gain 
> at 10
> > o'clock and Fold almost to 11 o'clock. 
> > 
> > John Loffink
> > jloffink@a... 
> > 
> > The Microtonal Synthesis Web Site
> > http://www.microtonal-synthesis.com/
> > 
> > The Wavemakers Modular and Integrated Synthesizer Web Site
> > http://www.wavemakers-synth.com/
> > > Yep, works for me.  COnfirmed it with a scope, too.
> > > 
> > > --- In motm@yahoogroups.com, "Oakley Sound" <oakley@t...> 
wrote:
> > > > > I could not get my Oakley Wavefolder to do the full wave
> > > rectification
> > > > by itself.
> > > >
> > > > Try setting the WF to the following:
> > > >
> > > > Gain set to around 2 o'clock.
> > > > Threshold set to mid point.
> > > > Fold set to around 10 o'clock.
> > > > Output to full.
> > > >
> > > > Output signal taken from main output. Clamp polarity will 
set 

> the
> > > > polarity of the output. Lower will give you positive only 
> signals.
> > > >
> > > > This will also act as octave doubler for triangle waves.
> > > >
> > > > Tony
> > > 
> > >