Wiardgroup

Well, I'm not exactly a newbie to synthesis, but am just begining my 
venture into the world of analog modulares, and I had a question 
that is probably totally basic, but here goes anyway.  Please feel 
free to laugh, curse or otherwise direct insults my way for what is 
probably very obvious:).

I noticed in the "Noise Ring" page that one of the mp3s had a NR and 
a Borg Filter together.  One of the Borg was being used as a 
standard filter, but the other was acting as a VCA.  Now, I've read 
about filters being used as VCAs before, and it seems particularly 
in conjunction with vactrol-based filters.  But, I'm not entirely 
sure how this would work.  I assume that if you adjust the cut-off 
in any way that it would be, well, filtering the sound.  So, then, 
how do you get a filter to amplify the sound instead of filtering 
it?  Perhaps with the resonance somehow?  

Again, sorry if this is painfully obvious, but I went to a football 
game today so maybe my IQ has been lessened by association:).

J.R. "Bulldogge" Ross
& Snuffy, too:)

hi jr,

basically, you feed an audio signal into the filter audio input and 
you patch the filter output to an amp for monitoring. with the 
frequency control knob fully open and no resonance added, you hear 
the waveform or audio without any coloration or filtering.

you then turn the frequency knob counter clockwise to eliminate all 
the audio. once you don't hear any audio at all, the filter is closed.
if you turn the knob from zero to max , you are controlling the 
filter much the same way a VCA behaves. 

now most filters have 1 input without an attenuator and 1 or 2 inputs 
with attenuators to voltage control the amount for the frequency 
range. to use the filter as a VCA, you send a control voltage to the 
frequency input on the filter. you can use an EG, an LFO , etc. to 
open and close the filter. 

to avoid hearing any filtering or coloration of the audio, it is best 
to avoid slow attack times, you basically want zero attack, zero 
decay, full level sustain or duration to open the filter quickly and 
whatever release level you want to close the filter accordingly (zero 
release, the filter snaps shut immediately, whatever release setting 
you chose and the filter closes accordingly).

using a filter as a vca is a good tool when you have run out vca's.

the best way to learn more about modular synthesis and its techniques 
is to recreate patches from owners manuals, academic books and 
suscribing to synth newsgroups. here are a couple of urls to point 
you in the right direction. good luck.

http://www.angelfire.com/music2/theanalogcottage/

http://theworld.com/%7Ejamzen/theBachWorks/arpman.html

http://home.t-online.de/home/BriJo.Mueller/basisxyz.html

http://www.cim.mcgill.ca/~clark/nordmodularbook/nm_book_toc.html

http://ds.kobedenshi.ac.jp/doepfer/

http://www.creativesynth.com/

http://www.modularsynth.com/

http://hem.passagen.se/tkolb/art/synth/intro_e.htm

http://www.musicsynthesizer.com/

i can't list every url i have, but this should get you started. 
always follow the links at each site you visit to find out more 
sources out there. the last link is a great portal to the synth DIY 
world out there, it will inform you of the concepts and theories 
behind the front panels of the modules.

happy surfing and discovering,
RM


--- In wiardgroup@yahoogroups.com, "jrbulldogge <jrbulldogge@y...>" 
<jrbulldogge@y...> wrote:
> Well, I'm not exactly a newbie to synthesis, but am just begining 
my 
> venture into the world of analog modulares, and I had a question 
> that is probably totally basic, but here goes anyway.  Please feel 
> free to laugh, curse or otherwise direct insults my way for what is 
> probably very obvious:).
> 
> I noticed in the "Noise Ring" page that one of the mp3s had a NR 
and 

> a Borg Filter together.  One of the Borg was being used as a 
> standard filter, but the other was acting as a VCA.  Now, I've read 
> about filters being used as VCAs before, and it seems particularly 
> in conjunction with vactrol-based filters.  But, I'm not entirely 
> sure how this would work.  I assume that if you adjust the cut-off 
> in any way that it would be, well, filtering the sound.  So, then, 
> how do you get a filter to amplify the sound instead of filtering 
> it?  Perhaps with the resonance somehow?  
> 
> Again, sorry if this is painfully obvious, but I went to a football 
> game today so maybe my IQ has been lessened by association:).
> 
> J.R. "Bulldogge" Ross
> & Snuffy, too:)

Ah, thanks, now I get it.  You aren't actually amplifying the signal 
when using a filter this way, but rather de-amplifying it, if you 
will by using the closed/open nature of the filter to control the 
overall volume level.  That I understand, I just didn't get how a 
filter could amplify the signal rather than cut the signal.  

Thanks for all the links.  I've seen some of them, but they all look 
useful.  While I've learned many synthesis techniques with hardwired 
synths (both analog and digital) and also with the Nord Modular, 
obviously only a limited amount of that transfers over to the world 
of analog modulars.  One thing it seems that I've got to work on is 
thinking "outside the box" as it were, or at least around the box.  
Thus, using a filter's closing capabilities to mimic an amplifier's 
ability to strengthen a signal.

Thanks, and I will definitely read as much as I can on those links, 
as well as wherever they may lead me.  In the end I'm sure the best 
way to learn will be to get a decent system and patch away--
hopefully rather soon, and definitely containing several Wiard 
modules (I really like the Noise Ring examples, and the 
possibilities seem quite fun).


J.R. "Bulldogge" Ross
& Snuffy, too:)

Why was the Borg used as a VCA?  Because it has a VCA mode.  The Borg 
Filter is a further developement of the Buchla low pass gate, which had 
three modes - vca, filter, and both.  When the Borg is swtiched to VCA 
mode, the filter is a single pole filter with no resonance.  This is 
similar to the "both" mode of the Buchla, which Don Buchla described as 
a "pcsychoacoustic" feature - that the frequency spectra should drop as 
the volume deminishes. 

gary chang 

--- In wiardgroup@yahoogroups.com, "jrbulldogge <jrbulldogge@y...>" <
jrbulldogge@y...> wrote:

> Ah, thanks, now I get it.  You aren't actually amplifying the signal 
> when using a filter this way, but rather de-amplifying it, if you 
> will by using the closed/open nature of the filter to control the 
> overall volume level.  That I understand, I just didn't get how a 
> filter could amplify the signal rather than cut the signal.  
> 
> Thanks for all the links.  I've seen some of them, but they all look 
> useful.  While I've learned many synthesis techniques with hardwired 
> synths (both analog and digital) and also with the Nord Modular, 
> obviously only a limited amount of that transfers over to the world 
> of analog modulars.  One thing it seems that I've got to work on is 
> thinking "outside the box" as it were, or at least around the box.  
> Thus, using a filter's closing capabilities to mimic an amplifier's 
> ability to strengthen a signal.
> 
> Thanks, and I will definitely read as much as I can on those links, 
> as well as wherever they may lead me.  In the end I'm sure the best 
> way to learn will be to get a decent system and patch away--
> hopefully rather soon, and definitely containing several Wiard 
> modules (I really like the Noise Ring examples, and the 
> possibilities seem quite fun).
> 
> 
> J.R. "Bulldogge" Ross
> & Snuffy, too:)