Mutant Vactrol Filter

[Scott Stites]

To my embarrassment, I grew up completely oblivious to Buchla and Subotnick. It was only when I got back into Synth DIY (after a brief flirtation in the mid to late '80's) in 2002 that I 'discovered' Buchla.

Peter Grenader, who I think graduated from Mills later than Howard, studied under Subotnick and frequently mentioned his works. Out of curiosity, I got 'Silver Apples of the Moon' and 'The Wild Bull' on CD. It fundamentally changed the very core of my view of Electronic Music and sound synthesis in general. Absolutely brilliant stuff. I still listen to it at least once a week - on my way to work, I can hear the full 'Silver Apples of the Moon' and on the way back 'The Wild Bull'. It seems as if there's always something new in there I hadn't noticed before. That work was rendered on the Buchla 100 system.

I've got 'Touch' and 'A Sky of Cloudless Sulphur' now as well, which was done on the 200 system, if I'm not mistaken. Both are continuations of the genius.

The Buchla creations themselves seem to take on a life of their own. I've 'adapted' the 292, 291 and 266 modules and bit parts of the Music Easel (breaking only the fundamental rule of combining the audio and control structures - no mean feat considering the control signals were mostly unipolar). It seems if I use any of them in a patch, the very nature of the modules just takes over. Seriously, they just change the nature of how I patch and what I come up with. I can't imagine what programming a real Buchla system must be like, but I've always wanted to try.

The Buchla approach places as much importance, if not more, on frequency, amplitude and non-linear waveshape modulation as it does on standard subtractive synthesis. Check out the operation manual of the Music Easel. Filtration is mentioned almost in passing.

http://www.wavemakers-synth.com/buchla/PaMtEO.pdf

It's called "Programming and MetaProgramming the Electro Organism: An Operating Directive for the Music Easel"

I urge anyone into synthesis, whether they like Buchla or not, to read this - it's quite an eye-opener and opens so many doors as well, even if you don't have a Music Easel. If you've got a modular, especially the NM, a lot of the technique can still be accomplished.

Cheerio,
Scott

[3phase]

[quote="v-un-v"]

[3phase]

[mosc]

I don't think Buchla would care to associated with a school of thought. He just does what he feels like. My guess is he's not particularly interested in being the leader or the father of synthesizer design. Paying homage to other designers is not on most designer's minds when they make circuits.

I've mentioned it before, but Buchla said the imporant thing is to design the front panel first. I think he's be very bored by discussions of circuit details.

So, even though he might have used vactrols in certain circuits, that's not the important thing. He used to laugh at people that talked about the difference between the Moog and Buchla sounds. He didn't have much patience for that kind of thing.

[Scott Stites]

The Music Easel actually was made up of two 200 series components - the 208 Stored Program Source and the 218 keyboard. I read somewhere how many of the Music Easels themselves were produced, but can't remember the number - shockingly low, 20 maybe?

Buchla has a page about it here (click the picture to see a beautiful pic of the thing):

http://www.buchla.com/historical/music_easel/music_easel.html

There's a huge amount of power in a tiny little box.

There's an EM artist, Charles Cohen, that performs with the Easel:

http://www.voicenet.com/%7Eccohen/

I'd love to catch one of those shows!

I'm not sure how large of a patch an NM can handle. The main thing about the manual that I like is the exposition it gives to different techniques themselves rather than the standard VCO->VCF->VCA route. Would be cool if you could patch the entire Easel....

[mosc]

Maybe Charles Cohen will show up at electro-music 2006...

[Scott Stites]

[mosc]

[Scott Stites]

Well, I should never say never - I'd *love* to go - maybe they'll send me to Philly for some field cals. I was lucky enough to meet Rene Schmitz a couple of years ago on a field trip...

Cheers,
Scott

[bugbrand]

Hey, thanks for a mighty interesting discussion with so many varied ideas. Its great to hear about the wonderfully different and creative ethos behind Buchla.

Reading through the Music Easal manual is, indeed, really interesting and useful (I think Howard had previously recommended to someone that examining the features of different modulars gives a great insite into what features you want to include into your own designs and how to lay them out) - - it's all about interface -> precisely ties in with designing frontplates / controls before the circuitry - - Loving this because its again the fertile meeting of science and art.!

[Scott Stites]

Yes indeed - I've learned a lot about what I want by studying the functions of various synths. The Buchla panels in particular are (to me) an excellent marriage between functionality and art - the 200e in particular is just dazzling to look at!

Tom - I've read that the Compact A was used on TD's 'Phaedra' - not sure if that's true or not.

I'm hoping to incorporate the regen path into my phaser - probably won't sound the same, but I think it will be interesting to try.

The idea with my phaser is to have two chains of up to 12 stages each. The chains could be run in series for up to 24 stages, or in parallel for up to 12 stages per channel.

For each chain, the output tap and regen tap would be separately selectable on every two stages. Regen polarity could be switched, and the insertion point for the regen could be made so that the number of stages for regen could be odd or even. I've tried the number of stages/regen path of the compact A previously, but I'd like to see what effect low passing it in the manner they do has on the sound.

Some phasers incorporate fixed stages in the path - this phaser could do that as well. In this case, running in series would allow one of the chains to be fixed while the other would be swept. The number of fixed stages could be set in the same manner that the number of stages could be selected in normal swept operation. The fixed stages could be either before or after the swept stages - just depends on which chain one wants to sweep.

Even running in series, the output could still be stereo - tapping one output from one tap and the other output from a different tap creates a pretty nice stereo image.

Cheers,
Scott

[zipzap]

I got to try this stuff. If someone knows about all thos types of vactols please check this link to my dealer and tell me if any of these could be of use. I can´t find any of those 5c3s. Many will work i guess...
http://www.reichelt.de/
go under bauelemente, aktiv/ Optoelektronik/ optokoppler
Thanx

[Scott Stites]

From what I can tell, those are opto coupled transistors? What you want is an opto coupled LDR (light dependent resistor also called cds cell or other things). If you can find just the LDR but can't find the whole LED/LDR package like the Vactrols, you can make your own optocoupler by bundling the LDR and LED together in a light proof package. I've seen shrink wrap used.

Or, in the case of the phase shifter, you can try Motohiko's 'LDR's sitting around the campfire' approach - IE, position the LDR's around a single LED and just put something light-proof over that.

http://www.netsurfer.aleph.co.jp/~takeda/radio/phaser/index2E.html

Looks like the Compact A did something similar, using two campfires with four LDR's toasting marshmallows around each one

Take care,
Scott

[blue hell]

[v-un-v]

Cripes! I just remembered 4ms pedals- thay also do a fabulous sounding/looking vactrol phaser- the phaseur fleur

http://www.commonsound.org/
4ms are a bit like Ray Wilson too- as all thier designs are free for you to download, but they also make boards for you to buy- and have one of the nicest philosophies for and about education I've ever seen or found. Power to the people!

Does anyone agree with me that Boss phasers sound like a cats being sick? I really dislike the sound boss phasers make- but the SE70- if you put percussion through it sounded like someone plucking their vocal strings!

[v-un-v]

[Scott Stites]

I think what Jan is getting at is that the brightness of an LED depends on how much current is drawn through it. When you modulate the LED, you're not modulating it 'on and off', but rather varying the brightness linearly with the amount of current you're sucking through it.

The effect of slew in an LDR only becomes relevant at higher modulation rates, or with sharply changing transients modulating the light source.

I don't discount that there would be differences using a lamp as opposed to LED's, though.

Cheerio,
Scott

[blue hell]

[v-un-v]

nope- you're both right and I'm talking a load of bollocks.. I've had a very difficult weekend and now see the errors of my ways !

time for the bathtub

[blue hell]

[DrJustice]

[dnny]

[Scott Stites]

Wow!!!!

[mosc]

[DrJustice]

Ahh.. I understand; privately amused/annoyed by "hi-fi mumbo jumbo" style comments

Back to Mutant Vactrols then!

DJ
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