Bode Frequency Shifter VST

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Nice!
Play it by ear

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I'm presuming this is Synthedit like your other plugins? Are you using Christian Budde's Frequency shifter module or is this something else? I've been playing around with Christian's frequency shifter myself and i've been thinking about trying to make one using other modules (just for fun/my own educational purposes) so I'm just asking out of personal interest.

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chuck death wrote:I'm presuming this is Synthedit like your other plugins? Are you using Christian Budde's Frequency shifter module or is this something else? I've been playing around with Christian's frequency shifter myself and i've been thinking about trying to make one using other modules (just for fun/my own educational purposes) so I'm just asking out of personal interest.
No, this is a complete different design. I tried the DAV module, but it did not ouput any sound (?). Also I find all of Christian's modules very buggy and experiented too many crashes with them.
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Bump, so I don't forget about this...

IsitdoneyetIsitdoneyetIsitdoneyet???

:wink:

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Shabdahbriah wrote:Bump, so I don't forget about this...
IsitdoneyetIsitdoneyetIsitdoneyet???
:wink:
So much to do, so little time....
LFO- and envelope-control must be done also, and the GUI is not finished yet....
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Very nice GUI! 8)


Martin

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I'm really looking forward to use this 'thing'... :love:

Best regards,
Bertil

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cant wait for this one ! brilliant interface, too !

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I'm a little confused. How does this effect differ from ring modulation again? Could somebody explain it a little better?

Very cool plugin BTW. 8)

EDIT: After doing some reading, it seems that the Bode frequency shifter is basically just a ring modulator, the difference being that the upper and lower sidebands are sent to separate outputs so that you can eliminate one or the other sideband. Is this correct?

Seems like it would be a useful effect. I'm surprised it hadn't been implemented in a plugin before.
"The Juno 60 was often incorrectly referred to as a synth. It is, in fact, a chorus unit with a synth attached." -PAK

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afreshcupofjoe wrote:EDIT: After doing some reading, it seems that the Bode frequency shifter is basically just a ring modulator, the difference being that the upper and lower sidebands are sent to separate outputs so that you can eliminate one or the other sideband. Is this correct?
This is basically correct (where a standard ring modulator has two inputs, while the frequency shifter has only one; the shifting is done with an internal oscillator.)
But while sounding simple, the design is much more difficult than a ring modulator, which can only output both signals together. And the frequency range is different too. Shifting a signal up 1Hz for example is possible, while a ring modulator would do an amplitude vibrato only.
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Sounds like fun using this plugin :)
Thank you.
The more I hang around at KVR the less music I make.

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Hi. I use Hematohm all the time to add a vintage-sounding phase shifted LFO wobble to my synth lines. Will your new Bode be a comparable effect to that? I hope so. I would purchase in an instant - nothing wrong with Hematohm, of course, but you can't have enough of a good thing. :)

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WOK wrote: But while sounding simple, the design is much more difficult than a ring modulator, which can only output both signals together. And the frequency range is different too. Shifting a signal up 1Hz for example is possible, while a ring modulator would do an amplitude vibrato only.
Thanks for the insight. I don't know much about programming, but I took a look at the schematic on the US patents website, and it's a pretty clever little trick they used to accomplish the cancellation of the upper/lower sidebands.

If anyone is interested:
http://www.till.com/articles/moog/paten ... US03800088

I imagine a similar trick is used to code it up using dsp? Or is it a completely different approach?
"The Juno 60 was often incorrectly referred to as a synth. It is, in fact, a chorus unit with a synth attached." -PAK

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I loves me some Hematohm, but I can't wait to get this one, WOK 8)

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afreshcupofjoe wrote: I imagine a similar trick is used to code it up using dsp? Or is it a completely different approach?
Fairly similar approach. The separation of the audio signal into real and imaginary components is done with 2 parallel allpass filters in both the analog and digital domains, commonly called a "phase differencing network" or Hilbert network. Scott Wardle wrote a paper in 1998 about how to create such an allpass network through the transformation of an elliptical filter. The math for that paper was over my head, so in 1999 I created a version based around the bilinear transform of an existing analog phase differencing network, from an old issue of Electronotes. This version made it into Csound, and I later ported it to Supercollider and Reaktor. The bilinear transform of an existing analog prototype seems like a more common approach nowadays.

The Moog/Bode patent has a complicated circuit for the quadrature oscillator. In the digital domain, quadrature oscillators are way easier - just a ramp oscillator that is waveshaped by sine and cosine (the actual realization is usually optimized beyond this simple description, but same idea).

Digital frequency shifters don't need a squelch circuit. This was an attempt to suppress feedthrough of the quadrature oscillator when there is no input signal, as analog ring modulators of the time had fairly poor performance. A digital ring modulator is a simple multiply - in the code, you just type "*" and you get great performance.

Sean Costello

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