MultiPhase Project

piedwagtail · Posted: Wed May 03, 2006 4:25 pm Post subject:

Dancing Burroughs....that's some opportunity....did he shuffle or glide?

but...returning to your topic i haven't listened to any Banshees for 20yrs,so i had to check the samples about and it seems that both Kaleidoscope and JuJu have a good deal of swirling guitar and shimmering pulses.Either it has something to do with Nigel Gray,the producer or the late John Mcgeoch,guitarist,who was in PIL for awhile.

Robert

Scott Stites · Posted: Thu May 04, 2006 9:43 am Post subject:

He glided quite well, IIRC. Further OT: I don't get HBO at home, but last March I was stuck in Chicago at a hotel that did. The series "The Sopranos" used a piece from Material that had William himself reciting his poem 'Seven Souls'. What a great piece of work, all around. As HBO is wont to do, they played that same episode, what, a hundred times during my week and a half spent there. I'd tune in every time just to hear that piece.

I'll definitely give S&B a listen!

Thanks,
Scott

Scott Stites · Posted: Mon May 15, 2006 9:57 am Post subject:

I've added a bit to the MultiPhase page and the MultiPhase itself since my last post here.

To the MultiPhase I've added:

1. Cross Regeneration
2. Wet Signal Crossfaders

I think that's it?

To the page I've added block diagrams of the final product. The only thing on there I haven't put on the board is the Envelope Follower. For that, I'm probably going to avoid a Vactrol based EF - I'd like sharp response, and Vactrol+Vactrol does not spell sharp. I'm probably going to employ the EF from Rene Schmitz's page (based on an Elektor design - really more of a specialized S&H than a standard EF). That will be followed by a simple lag processor - no more room on the panel for anything fancier. I have laid out the panel, BTW, though it's not pretty yet. Everything fits on a 3U rack panel. Yeah, pretty large for a phase shifter, but no larger than a Roland PH-830.

Anyway, the crossfading of the wet signals turned out to be a really cool thing, I think. I used Vactrol crossfaders. Here's a sample that pretty much demonstrates what they do. It has both phase banks modulated anti-phase by a triangle/pulse with the crossfaders modulated by a third triangle.

There are 7 more samples in various states of modulation and undress here:

http://mypeoplepc.com/members/scottnoanh/birthofasynth/id18.html

Cheers,
Scott

piedwagtail · Posted: Tue May 16, 2006 7:09 am Post subject:

Stockhausen Verlag today issued a cease and desist notice to Mr.S.Stites for infringement of copyright in the previous sample of Herr Stockhausen's Helicopter String Quartet.
http://www.stockhausen.org/heli_mp3.html

Wink

Robert

Scott Stites · Posted: Tue May 16, 2006 2:41 pm Post subject:

Doomed! Those Stockhausen lawyers will eat you alive Very Happy

Darn thing won't play here at work - I imagine it's because of the firewall. I'm going to give it a listen tonight.

Cheers,
Scott

blue hell · Posted: Tue May 16, 2006 2:49 pm Post subject:

Scott Stites · Posted: Thu Jun 01, 2006 10:07 am Post subject:

The MultiPhase raises it's many headed...um...head again.

I've hunkered down and spiffed up/added to the website.

There are now two MultiPhase pages:

The original page has been converted into a progress journal, with the sound clips and so forth:

http://mypeoplepc.com/members/scottnoanh/birthofasynth/id18.html

Panel design, what schematics are finished, waveshaping, general tech stuff is on the new project page here:

http://mypeoplepc.com/members/scottnoanh/birthofasynth/id19.html

Since my last post on the subject:

I've put together the Phase A and Phase B boards, posted the schematic, designed the fantasy panel, posted that, added quadrature offset for bank B (a Thomas Henry thang), added an envelope follower, and have worked out an easier hypertriangular waveshaping scheme (a la Thomas Henry again).

Quadrature modulation sound samples and some EF samples are up as well.

Cheers,
Scott

piedwagtail · Posted: Thu Jun 01, 2006 12:07 pm Post subject:

Hey,Mr.Vactroality,

this analogue phase computer is the densest synth diy i've seen,rates above those extended Bode shifter and walsh function interminables.
Thank cripes,you've put some block diagrams up but crikey i need a block diagram of the block diagrams....
Amazes me that you term this endeavour 'glacial', like to see any other music tech engineers keep this pace up and hold down another job.
And that audio rate modulation sample,it bears no resemblance to the previous dry sample whatsoever,that's the sign of man out in his own galaxy....i didn't know vactrols were that quick.
4 double sided boards in EagleCACK and a frontplate, and you've got a stall at NAMM this year.
(+ lab assistant upfront handing out candy to entice them attendees).

flippin' heck,mon Smile

Robert

Scott Stites · Posted: Thu Jun 01, 2006 9:44 pm Post subject:

Hey Robert,

Very Happy

I always get a kick out of your posts.

This thing has certainly turned into a monster. A friend who saw the panel drawing remarked that it had more knobs than a Korg MS-20 Shocked

It really did start out as a simple phase shifter, but the more I played with the design, the more interesting sounds it began to produce. I'm really surprised at the multitude of things a tricked out, multi-stage phase shifter can do. It'll do the things I commonly associate with phase shifters (provide the typical phase shifter sweep), but all of the other things having a number of control sources, etc. enable it to do has really blown me away. It can sound startlingly 'unphaser-like' at times. Hence my pursuit of a phase shifter that's got more knobs than a semi-modular synthesizer.....

Cheers,
Scott

zipzap · Posted: Fri Jun 02, 2006 1:08 pm Post subject:

Hi Scott
This is cool! I spent the last hour listening to those samples on your pages. Awesom.
You certainly did a lot of writing discribing those projects. Lots of motivation for me!
And this phase shifter that looks and sounds like a whole synth: It truly deserves every single pot.

Scott Stites · Posted: Fri Jun 02, 2006 8:32 pm Post subject:

Thanks, ZipZap!

I plan to put all the details on the page as I run across them. I think anybody could go any direction they wanted with that core board. After I'd built the first one, I realized one could fit in a mid-sized synth module. Without all the modulation options, there's really not a lot too it (the modulation of course would be provided by the synth itself). A 16 stage synth module would be pretty cool. But, for now I'm wanting to stick with the rack mount version.

I've been working on figuring out if a selectable inversion of the wet signals might benefit the stereo crossfading. It seems to add a whole new range to crossfaded mono signals for sure. But things have been interrupted by real life - my Grand Am went to the great car heap in the sky, just 24 miles short of 200,000 (head gasket went out quite spectacularly).

I got so lucky I can't believe it, though - found a German car I can actually afford (used, but so cherry). I just hope the surprise isn't too great when tax time rolls around. Better buy my 3U panel before that hits Very Happy

Cheers,
Scott

Uncle Krunkus · Posted: Sat Jun 03, 2006 8:55 am Post subject:

I just checked what you've been up to Mr Stites! Shocked

Some very impressive work. Smile

You're out there honing the cutting edge of phaser technology!
"Somebody get this man a Nobel Prize! or an OBE!! or a beer at least!"

Scott Stites · Posted: Sun Jun 04, 2006 1:55 pm Post subject:

Why, thanks Uncle K. What's a good Aussie beer? Is Fosters really preferred down under (like the media hype here intimates) or is it considered to be passe amongst the populace?

I've added some text and a schematic for the wet signal voltage controlled crossfader section of the MultiPhase. It's Vactrol based and works very, very well for about any signal you'd want to crossfade. IE, it works well in a modular for, say, crossfading VCO waveforms - crossfading a sine with a sawtooth or pulse, for example, can be pretty cool stuff. It's definitely fun to watch on an oscope.

It's at the bottom of the project page here:

http://mypeoplepc.com/members/scottnoanh/birthofasynth/id19.html

Cheerios,
Scott

Uncle Krunkus · Posted: Sun Jun 04, 2006 2:22 pm Post subject:

I would never touch Fosters (just not part of my upbringing I spose)
The standard for city folk of my generation is Victoria Bitter or VB Smile

I also like a Hahn Premium if I've got some extra cash Cool

zipzap · Posted: Sun Jun 04, 2006 4:11 pm Post subject:

i like the title picture

23isgood · Posted: Tue Nov 28, 2006 2:07 am Post subject:

Hi everybody my name is Pete and i'm new here, and i'm kinda a noob, though I have built quite a few modules over the last few years. I am very interested in Scott's Multi Phase project and I would like to test on the bread board a four stage version of Scott's phaser. My first question is concerning the VTL5C3/2.

After looking at Scott's Mutant VCF I can see that the vactrols have two LDR's inside and one LED. So according to the Multi Phase schematics, VT101A and VT101B are these two LDR's inside one vactrol?

So the middle lug on the vactrol (pin 4) and the third lug (pin 5) are going to -15 volts? Hum i'm kinda stumped since the data sheet show only one LDR inside,

http://optoelectronics.perkinelmer.com/content/Datasheets/DTS_vtl5c2232.pdf

thanks
pete

Uncle Krunkus · Posted: Tue Nov 28, 2006 6:45 am Post subject:

I think it's just the middle lead (4) going to -15V. The other two leads are the other side of what are effectively two separate LDRs. (the diagram is a bit counter intuitive, but an LDR with a centre tap is the same as two LDRs)

Scott Stites · Posted: Tue Nov 28, 2006 7:31 am Post subject:

Yep, the VTL5C3/2 has two LDRs in it, and one LED, so VT101A and VT101B are the same device.

Pin 4, the center pin, would be connected to ground, not -15V (notice the fat downward arrow is ground, the skinny downward arrow is -15V).

It'd probably help if I put the Vactrol pin numbers on there - hadn't thought of that! By golly, I'll do it.

Cheers,
Scott

vtl5c3 · Posted: Tue Nov 28, 2006 9:59 am Post subject:

Scott,

I've got another vactrol phaser project on the back burner pile (huge pile, but I think you can relate). The main reason I shelved it is because of overdrive problems when feeding back the audio. I see that you ran into that with the Multiphase as well and cured it with a limiter. I see that you used a THAT application note, but which circuit did you use? The one based on the THAT 2180 or the 4301?

Romeo

Scott Stites · Posted: Tue Nov 28, 2006 11:18 am Post subject:

Hey Romeo,

It's the THAT2180 soft knee limter/compressor. The THAT4301 wasn't really available to me at the time.

Yes, ditto on the projects. If I could retire today, I could spend the rest of my life, 24/7, catching up on all the things in the queue.

Cheers,
Scott

23isgood · Posted: Tue Nov 28, 2006 11:58 am Post subject:

Ok so the middle lead (pin 4) goes to ground, what about pin 5? Does it go to ground too? Scott, labeling the pins would be great! Please let me know when its done. I'm sure you are very busy, and I am with school, so no hurry.

I love your projects by the way. So far I have built three Thomas Henry XR VCO's, and I have to say they sound awesome! I will be posting some samples here soon. Also on my huge to build list, is the SN Voice, and some of TH's drum modules. I scored a few 566's and 3080's just for Thomas's projects.

Thanks guys for the help,
pete

Scott Stites · Posted: Tue Nov 28, 2006 4:21 pm Post subject:

Cool! I'd love to hear those samples!

Cheers,
Scott

23isgood · Posted: Wed Nov 29, 2006 9:37 am Post subject:

Hi Scott. I just put up a new thread with a link to the samples, and a pic of one of the boards.

pete

State Machine · Posted: Sat Dec 02, 2006 11:54 am Post subject: