MOTM

Just daydreaming out loud...

I was just thinking about how most synthesizer 'modifier' modules function
by changing the relative amplitudes of a sound's partials. This is true of
the family of x-pass filters, phasers, waveshapers, clippers, VCAs, etc.
They all change harmonic amplitudes in one manner or another. It seems to me
that the vast majority of them work this way.

What do we have for the frequency domain? Besides the Ring Modulator (and
it's close relative the Frequency [not Pitch] Shifter, is there anything
that lets you change the frequency, rather than amplitude, of individual
partials with respect to one another? Ring Modulators and Frequency shifters
work 'all or nothing' in a linear (sic) way. It seems like the only way to
do further, more flexible mutations of this sort is to go to additive
synthesis via a *lot* of VCOs or something.

I guess FM synthesis attempted to address this in its way. And every now and
then someone gives thought to perhaps new basic waveforms, but none have
proven themselves as useful as the 'big 4.'

I dunno... seems like there should be more devices in this category, that
function in this domain. Something to retune partials in ways different than
a Ring Modulator.

Back to my reverie...

You know, I have checked that out, but I'm unfamiliar with Walsh Functions.
I'd love to know what it sounds like, and what it's like working with this
machine.

 -----Original Message-----
From: 	Dave Bradley [mailto:daveb@...] 
Sent:	Monday, 20 March, 2000 4:12 PM
To:	motm@onelist.com
Subject:	RE: [motm] Modules for Pushing Partials Around

From: "Dave Bradley" <daveb@...>

For something pretty hairy, check out an analog alternative to Fourier
analysis/resynthesis using Walsh functions on Tony Allgood's site:

http://www.techrepairs.freeserve.co.uk/walsh.htm

Tony says he's built a partial implementation of this beast, maybe he can
comment on the sound possibilities...

Dave Bradley
Principal Software Engineer
Engineering Animation, Inc.
daveb@...

For something pretty hairy, check out an analog alternative to Fourier
analysis/resynthesis using Walsh functions on Tony Allgood's site:

http://www.techrepairs.freeserve.co.uk/walsh.htm

Tony says he's built a partial implementation of this beast, maybe he can
comment on the sound possibilities...

Dave Bradley
Principal Software Engineer
Engineering Animation, Inc.
daveb@...

> From: "Tkacs, Ken" <ken.tkacs@...>
>
> What do we have for the frequency domain? Besides the Ring Modulator (and
> it's close relative the Frequency [not Pitch] Shifter, is there anything
> that lets you change the frequency, rather than amplitude, of individual
> partials with respect to one another? Ring Modulators and
> Frequency shifters
> work 'all or nothing' in a linear (sic) way. It seems like the only way to
> do further, more flexible mutations of this sort is to go to additive
> synthesis via a *lot* of VCOs or something.
>
> I dunno... seems like there should be more devices in this category, that
> function in this domain. Something to retune partials in ways
> different than
> a Ring Modulator.
>

>For something pretty hairy, check out an analog alternative to Fourier
analysis/resynthesis using Walsh functions on Tony Allgood's site...

Oh yes, that thing. Yes I really must dig it out again. I never managed
to get the thing in a box. I had a change of tack and decided to build
myself a modular and forgot about it. Yes, I will eventually get the
thing modularized (?). I want to fit a morphing controller on it so I
can control its 31 VCAs with a single envelope generator. I've worked
out how to do it, but its a question of time and money at the moment.

Its sounds very nice really. Closest thing to rival it, is the PPG or
digisound VCDO module. However, its something nice to have two banks of
31 sliders to play with. It also managed to a do very good DX-7 electric
piano!!!

On another topic, I managed to get a saw-tri-inverse saw VCO module to
work as well. We had a discussion about it on the DIY list a while back.
I used Don Tillman's idea of two VCAs controlling an arithmetic minimum
circuit. It worked very well, similar to PWM in some ways. However, the
output waveform suffered from poor DC offsets and it was impossible to
get the design to produce a decent sync, so I abandoned the project for
now. Another one to come back to when time allows.

Regards,

Tony Allgood  Penrith, Cumbria, UK

http://www.techrepairs.freeserve.co.uk/

In a message dated 00-03-20 14:56:43 EST, you write:

<< Back to my reverie... >>


ken,
i would say you`re correct on your musings....... maybe we need someone with 
some technical design skills to take a serious look at the "problem" and see 
if any solutions present themselves.  additive synthesis is fun but a monster 
to try and coordinate plus you need a "large-ish" system. there have been a 
few harmonic bank type modules over the years, i believe buchla had 2 or 3 
types for his 100 / 200 series modulars. walsh functions have been looked at 
as another approach but have their own problems, too.
any ideas, anyone ?
best,
dave v.

In a message dated 00-03-20 16:16:33 EST, you write:

<<  Fourier
 analysis/resynthesis using Walsh functions on Tony Allgood's site: >>



dave,
his approach seemed to focus on using walsh summation to duplicate "analog" 
waveshapes although certainly you could sum different things and try for odd 
waveforms. same problem here as with regular vco`s - you need a lot of vca`s 
and eg`s to modify the partials prior to summation to get dynamic timbral 
effects. still, in some ways, this approach might be simpler and cheaper than 
building 8 vco`s but also would lack the overall flexibility you would gain 
from having 8 vco`s to use in other capacities as needed.
best,
dave v.

In a message dated 00-03-20 16:17:40 EST, you write:

<< I'm unfamiliar with Walsh Functions >>



ken,
think of eccentric pulse waves with varying "phases" in relation to each 
other and the 0 degree ( dc ) point.  if you have access to "electronotes", 
they did a lot with them back in the late 70`s.
best,
dave v.

Electronotes seem to be the Holy Grail of synth DIY. Everybody talks about
them but copies seem to be impossible to come by!





ken,
think of eccentric pulse waves with varying "phases" in relation to each 
other and the 0 degree ( dc ) point.  if you have access to "electronotes", 
they did a lot with them back in the late 70`s.
best,
dave v.

Thomas Henry (Midwest Analog Products among other claims to fame) has info
online about getting ahold of Mr. Hutchins:

http://mall.lakes.com/~map/enotes.htm

The entire set of reprints is $265.


>
>Electronotes seem to be the Holy Grail of synth DIY. Everybody talks about
>them but copies seem to be impossible to come by!
>
>
>
>
>
>ken,
>think of eccentric pulse waves with varying "phases" in relation to each
>other and the 0 degree ( dc ) point.  if you have access to "electronotes",
>they did a lot with them back in the late 70`s.
>best,
>dave v.
>
>
>

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com

The word on the electronic music street supports what you're saying. I hear
that Mr. Hutchins jealously guards these things, but isn't very forthcoming
when you write him a check. That's very disappointing. I'm hesitant to write
a check for that amount to someone who's becoming notorious for not coming
across with the goods, as much as I'd like to get copies of these articles.

 -----Original Message-----
From: 	CHRIS PARKER [mailto:cparker@...] 
Sent:	Tuesday, 21 March, 2000 9:36 AM
To:	motm@onelist.com
Subject:	RE: [motm] Modules for Pushing Partials Around


I paid the $265 to Mr. Hutchins almost 2 years ago.  To date, I've received
about 90% of what he promised to include, and I consider myself lucky!  I've
talked to other people who have been waiting a lot longer and who have not
received as much as I have!


If anyone out there has a full set, I'd really like to talk about getting
copies of the sections I am missing.  Electronotes really is a gold mine of
information on electronic music, and I would suggest it to anyone on the
list....just don't count on purchasing a complete copy from Bernie any time
soon!!!

I paid the $265 to Mr. Hutchins almost 2 years ago.  To date, I've received about 90% of what he promised to include, and I consider myself lucky!  I've talked to other people who have been waiting a lot longer and who have not received as much as I have!

If anyone out there has a full set, I'd really like to talk about getting copies of the sections I am missing.  Electronotes really is a gold mine of information on electronic music, and I would suggest it to anyone on the list....just don't count on purchasing a complete copy from Bernie any time soon!!!



>>> "james holloway" <jimh54@hotmail.com> 03/21/00 07:52AM >>>

From: "james holloway" <jimh54@...>

Thomas Henry (Midwest Analog Products among other claims to fame) has info
online about getting ahold of Mr. Hutchins:

http://mall.lakes.com/~map/enotes.htm 

The entire set of reprints is $265.


>
>Electronotes seem to be the Holy Grail of synth DIY. Everybody talks about
>them but copies seem to be impossible to come by!
>
>
>
>
>
>ken,
>think of eccentric pulse waves with varying "phases" in relation to each
>other and the 0 degree ( dc ) point.  if you have access to "electronotes",
>they did a lot with them back in the late 70`s.
>best,
>dave v.
>
>
>

______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com 


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This is a frequent discussion on synth-diy.  Too bad the whole thing could
not be scanned and condensed to CD for easy distribution.  I don't think
the issue is that Mr. Hutchins doesn't want anyone to have it, or he would
not offer it for sale.  It is more of the "getting around to" the copies
IMHO.
Larry H

----------
> From: Tkacs, Ken <ken.tkacs@...>
> To: 'motm@onelist.com'
> Subject: RE: [motm] Modules for Pushing Partials Around
> Date: Tuesday, March 21, 2000 8:35 AM
> 
> From: "Tkacs, Ken" <ken.tkacs@...>
> 
> 
> The word on the electronic music street supports what you're saying. I
hear
> that Mr. Hutchins jealously guards these things, but isn't very
forthcoming
> when you write him a check. That's very disappointing. I'm hesitant to
write
> a check for that amount to someone who's becoming notorious for not
coming
> across with the goods, as much as I'd like to get copies of these
articles.
> 
> 
>  -----Original Message-----
> From: 	CHRIS PARKER [mailto:cparker@...] 
> Sent:	Tuesday, 21 March, 2000 9:36 AM
> To:	motm@onelist.com
> Subject:	RE: [motm] Modules for Pushing Partials Around
> 
> 
> I paid the $265 to Mr. Hutchins almost 2 years ago.  To date, I've
received
> about 90% of what he promised to include, and I consider myself lucky! 
I've
> talked to other people who have been waiting a lot longer and who have
not
> received as much as I have!
> 
> 
> If anyone out there has a full set, I'd really like to talk about getting
> copies of the sections I am missing.  Electronotes really is a gold mine
of
> information on electronic music, and I would suggest it to anyone on the
> list....just don't count on purchasing a complete copy from Bernie any
time

> soon!!!
> 
> 
> 
> ------------------------------------------------------------------------
> PERFORM CPR ON YOUR APR!
> Get a NextCard Visa, in 30 seconds!  Get rates as low as 
> 0.0% Intro or 9.9% Fixed APR and no hidden fees.
> Apply NOW!
> http://click.egroups.com/1/2121/3/_/529958/_/953649814/
> ------------------------------------------------------------------------
> 
>

In a message dated 3/20/2000 12:56:36 PM, ken.tkacs@... writes:

>I was just thinking about how most synthesizer 'modifier' modules function
>by changing the relative amplitudes of a sound's partials. This is true
>of

<edit>

>is there anything
>that lets you change the frequency, rather than amplitude, of individual
>partials with respect to one another? Ring Modulators and Frequency shifters
>work 'all or nothing' in a linear (sic) way.

<edit>

>I guess FM synthesis attempted to address this in its way. And every now
>and
>then someone gives thought to perhaps new basic waveforms, but none have
>proven themselves as useful as the 'big 4.'

Ken, I haven't heard partials used in this way for so long, I thought you 
were talking about partial differential equations for an embarrassingly long 
time.

I agree entirely with what your saying, however, I think viewing waveforms as 
a composite of harmonics lends itself much more to digital (through Fourier 
analysis). It seems that when you view a sound as a waveform you are more "in 
tune" with the basic ""philosophy"" of "analog synthesis." As such, I think a 
more easily solvable engineering problem would involve manipulating the 
waveform in unconventional ways.

And my recent "bugging" of Larry involves mixing waves from a single 
oscillator (in and out of phase wrt each other) to produce another 
interesting wave (though nothing terribly special) -- BTW, the old Emu VCOs 
had a mixer output, I don't think the pots went negative though.

>I dunno... seems like there should be more devices in this category, that
>function in this domain. Something to retune partials in ways different
>than
>a Ring Modulator.

So this is where I usually start to rave about the unique timbres available 
from the Wave Multipliers (made by a competitor) in the hope that Paul will 
eventually be able to offer a similar type of module in the MOTM format. 
Timbre modulators of this type may not do precisely what you ask Ken, but I 
find they can easily make a one VCO patch sound great. In my experience, it 
is easy to get sounds like pick (or hammer) noise, or overblowing (flute, 
reed or trumpet) types of sounds which will "morph" into a more basic wave 
via VC. 

But recently my attention has been grabbed by a similar timbre modulator 
which is being made by Tony Allgood -- see his new Wavefolder PCB. Tony, does 
this compare in operation to the Wave Multipliers module? What size MOTM 
panel will it fit in?

JB

In a message dated 00-03-21 08:43:28 EST, you write:

<< 
 Electronotes seem to be the Holy Grail of synth DIY. Everybody talks about
 them but copies seem to be impossible to come by!
  >>



ken,
i believe paul told me that bernie hutchins, the person behind 
"electronotes", still sells the back issues. myself, i was a subscriber for a 
long time. i always found it to be a fascinating publication full of 
interesting ideas !
best,
dave v.

In a message dated 00-03-21 09:34:36 EST, you write:

<< If anyone out there has a full set, I'd really like to talk about getting 
copies of the sections I am missing.   >>



chris,
what was the stated last issue # ? i have from #1 to #160.  if bernie still 
has an active copyright it may not be legal / ethical for someone to provide 
copies.  :^(
i`m surprised he`s gotten so slow, back when i was subscribing, while issues 
frequently ran late, he filled orders pretty promptly.
short of some new super website or something with great info, IMHO, 
"electronotes" was the best source of synth diy type data ever available.
best,
dave v.

In a message dated 00-03-21 09:44:43 EST, you write:

<< I hear
 that Mr. Hutchins jealously guards these things, but isn't very forthcoming
 when you write him a check.  >>


ken,
gee, i hadn`t really tried to do anything with bernie lately but, from my 
experiences with him back in the late 70`s thru 80`s, he was always a 
reputable person to deal with. if thats changed, i`m both surprised and 
saddened........
best,
dave v.

Curly sez:

> And my recent "bugging" of Larry involves mixing waves from a single
> oscillator (in and out of phase wrt each other) to produce another
> interesting wave (though nothing terribly special) -- BTW, the
> old Emu VCOs
> had a mixer output, I don't think the pots went negative though.
>
>

True, the pots didn't go negative. However, the mixer was inverting so that
you had your choice of the noninverted output from the dedicated output jack
(SAW, TRI, PULSE, SINE), or the inverted output from the mixer. So you could
at least mix 100% strength noninverted waveforms with up to 100% strength
inverted waveforms, all onboard the VCO. Flexible but a panel space hog.

Dave Bradley
Principal Software Engineer
Engineering Animation, Inc.
daveb@...