Shepard tone (my first G2 patch)

jamos · Posted: Tue Jun 22, 2004 12:44 pm Post subject: Shepard tone (my first G2 patch)

A Shepard tone is an audio illusion that continously rises or falls in pitch. For more details on on Shepard tones, see http://www.mtsu.edu/~jnm2b/Shepard.html.

The key to doing this on a synth is the creation of phase-locked sawtooth and triangle LFO waves, with the phases of the various waves spread evenly across 360 degrees. I used LFO C to generate the phase-locked sawtooths, and then used rectifers and level convertors to convert these to triangle waves. Static shapers are used to round the triangle slightly, so that partials enter the mix smoothly.

Shepard Tone.pch2

Description:

A continuously rising or falling tone.

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Filename:

Shepard Tone.pch2

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4.67 KB

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2732 Time(s)

mosc · Posted: Tue Jun 22, 2004 3:02 pm Post subject:

Nice patch. Tt's a good one to keep in the synth for demos. You know, when you are showing off your gear and can't think of anything sparkling to say. Very Happy

I tried this on the original NM but didn't get it. Crying or Very sad

Thanks...

jamos · Posted: Tue Jun 22, 2004 3:16 pm Post subject:

I actually remember reading something once about a composer who used a falling Shepard tone in a piece - something about the nightmares of the bombardier on the Enola Gay - but it still seems to me to be of [i]very[/i] limited practical value :')

mosc · Posted: Tue Jun 22, 2004 3:30 pm Post subject:

Well, I'm a bit wacked out on medication now. It seems the challenge for making it useful would be to make this polyphonic - whatever that would mean in this context. At least something you can play - from a keyboard fr'instance.

ian-s · Posted: Tue Jun 22, 2004 4:24 pm Post subject:

Nice work. Like Howard, I have tried this in the past (with csound/softsynths etc) but without the same degree of success. I think YMO used it (to nice effect) on an album in the early 80's.

On the subject, while too trivial for it's own topic, here is a barberpole flanger. It uses nothing more than the FreqShifter with delayed feedback. I have to admit that I tend to overuse the FreqShifter, I just love the 60's analogue sound it gives to everything.

BarberPoleFlange.pch2

Description:

ever upward/downward sweeping flanger

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Filename:

BarberPoleFlange.pch2

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1.05 KB

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jamos · Posted: Tue Jun 22, 2004 4:52 pm Post subject:

Oh, I like that. And useful, too. Never knew a frequency shifter could be used like that.

Boy, do I have a lot to learn :')

mosc · Posted: Tue Jun 22, 2004 4:58 pm Post subject:

This is too neat for non G2 owners.

Here's an mp3 of Jamos' Shepard Tone.

shepard-tone.mp3

Description:

Shepard Tone

patch by James Johnson
recording by Howard Moscovitz

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Filename:

shepard-tone.mp3

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1.6 MB

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mosc · Posted: Tue Jun 22, 2004 5:02 pm Post subject:

The Barberpole Flanger is great. I've never heard this one. It's quite like the Shepard Tone - it just keeps going up and up. It's such a simple patch. Here's a screen scrape and an mp3 file.

barberpole-flanger.jpg

Description:

Screen shot of the barberpole fanger patch

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31.23 KB

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44532 Time(s)

barberpole-flanger.mp3

Description:

Barberpole Flanger

Patch by Ian Sayer
Recorded by Howard Moscovitz

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Filename:

barberpole-flanger.mp3

Filesize:

1.46 MB

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2675 Time(s)

seraph · Posted: Tue Jun 22, 2004 11:48 pm Post subject:

ian-s · Posted: Wed Jun 23, 2004 2:34 am Post subject:

seraph · Posted: Wed Jun 23, 2004 3:53 am Post subject:

jamos · Posted: Wed Jun 23, 2004 7:07 am Post subject:

mosc · Posted: Wed Jun 23, 2004 9:33 am Post subject:

Here is a Shepard Tone generated on a Kyma system. There are a bunch of adjustments I could fiddle with to make it a closer match to Jamos' patch, but it's interesting as it is for comparison purposes.

I think you're right, Jamos, about the aliasing. The MP3 encoding is having a detrimental effect on these examples.

kyma-shepard-tone.mp3

Description:

Shepard Tone made with a Kyma system.

Recorded by Howard Moscovitz

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Filename:

kyma-shepard-tone.mp3

Filesize:

1.39 MB

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2718 Time(s)

ian-s · Posted: Thu Jun 24, 2004 12:44 pm Post subject:

My apologies Carlos, I incorrectly assumed you were just exorcizing your razor sharp wit. Which BTW, makes this site an amusing place to visit.

seraph · Posted: Thu Jun 24, 2004 3:05 pm Post subject:

ian-s · Posted: Thu Jun 24, 2004 4:15 pm Post subject:

ooops, my mistake again, sorry Carlo

To much LDS in the 60's Wink

seraph · Posted: Fri Jun 25, 2004 5:09 am Post subject:

ian-s · Posted: Mon Jun 28, 2004 12:47 pm Post subject:

No, that's a quote, Kirk explaining Spocks odd behaviour in the Star Trek movie with the whales.
Actually, I didn't try LSD till the late 70's. I don't know what people see in it Wink

djfoxyfox · Posted: Tue Jul 06, 2004 2:15 pm Post subject:

mosc · Posted: Wed Jul 07, 2004 5:52 pm Post subject:

The barber pole patch is posted, just look more carefully...

djfoxyfox · Posted: Wed Jul 07, 2004 6:12 pm Post subject:

ian-s · Posted: Sat Jul 10, 2004 4:28 am Post subject:

Thought I had better update the flange patch, as V1.2 no longer has mix out. The new version simply uses a 2-1 switch for manual direction control. If you require 'voltage controlled' direction then use a x-fade instead. I also put a more musically relevant example in variation 2 (for those not so much into noise).

BarberPoleFlange.pch2

Description:

V1.2 Barberpole flanger by Ian Sayer

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Filename:

BarberPoleFlange.pch2

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2.93 KB

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djfoxyfox · Posted: Sat Jul 10, 2004 6:26 am Post subject: V1.2

egw · Posted: Sat Jul 10, 2004 6:44 am Post subject:

V1.2 will run patches from 1.0 or 1.1
but they changed a couple of modules, so it's not 100% compatible.