SergeModular

Best of luck with the Buchla shifter as it's one of Don's most aggressively
wack schematic layouts,

There's another list I belong to made up of EAM composers and one recently
posted the question if anyone knew of anything ever published regarding the
effects of pharmaceuticals on electronic music composition in the 70's and I
recommended he try the Buchla Owner's Manual.

Didn't get ONE laugh.

Well, I thought it was funny...


P

> Thanks to all who responded. It makes sense that a second
> phase shift network would be used on the FRSX.
>
> Steve Ridley suggested I look at the schematics for Buchla's 285
> Frequency Shifter for further clarity. It has both a built in thru-zero
> vco and a second input for audio signals. Neat module, actually.
> Also has a ring mod that cv crossfades between dry and
> processed signal.
>
> Romeo
>
> --- In SergeModular@yahoogroups.com, "metafoetus2002"
> <jan-hinnerk.helms@t...> wrote:
>> Hi,
>>
>> I'll try to have a shot at it,
>>
>> In a one-input frequency-shifter [FRS], the built-in signal is
> supplied by a built-in
>> sine-wave oscillator which outputs two sine waves of identical
> frequencies, but one of
>> this sine waves is 90 degrees out of phase compared to the
> other. Serge has such a
>> quadrature oscillator [QUO] as a separate module - also, the
> [VCFX] can be patch-
>> programmed to be used as such.
>>
>> The free input of the [FRS] has to pass thru a phase shifting
> network that allows for a
>> phase shift of 90 degrees. This phase shifting has to constant
> throughout the whole
>> frequency range. To build such a phase shifter is AFAIK what
> makes a frequency
>> shifter (from any brand) so costly.
>>
>> The [FRSX] needs two of those phase shifting networks, one
> for each input. It drops
>> the [QUO], but this seems not to make up for the money
> needed for the second phase
>> shifting network.
>>
>> I don't know if the [FRSX] also needs doubling the level
> compensation curcuits (it
>> might, if this treats the input signal and not the output signal on
> the [FRS]).
>>
>> Two questions from me to all owners and users of the [FRS]
> on SMOG: I could not find
>> any note on how low the shift frequency from the internal
> oscillator can go on the
>> [FRS] by (a) manual control and (b) voltage control.
>>
>> Second one. From trying out different frequency shifters on
> Musikmesse and NAMM, I
>> found out that there two different frequency shifter designs out
> there -- thru-zero-
>> ones and not-thru-zero-ones. On a thru-zero (e.g. Modcan,
> Bode, Analogue
>> Solutions or Systems, I always confuse these two) one you can
> turn the shifting
>> frequency not only very low, to say like 0.1 Hz, but you can also
> make it negative. If
>> negative, the upshift output becomes the downshift output and
> vice versa. As you can
>> voltage control the shifting frequencies, you can voltage control
> if downshift and
>> upshift outputs exchange places. This should be useful for very
> interesting stereo
>> effects (connect upshift to left and downshift to right).
>>
>> How does the Serge [FRS] fit in here? Thru--zero or not?
>>
>> Thanks,
>> Jan-Hinnerk
>>
>> --- In SergeModular@yahoogroups.com, John Papiewski
>> <johnp299792@a...> wrote:
>>> Yo,
>>>
>>> If you think of the FS as a souped-up ring modulator you
> might get
>> a
>>> clearer idea. Now, some ring modulators have one signal
> input and
>> they
>>> use a built-in oscillator to modulate your incoming signal.
> That's
>> like
>>> the first frequency shifter. Built-in oscillator.
>>>
>>> But some ring modulators have two open inputs so you can
> modulate
>>> anything against anything. The Serge ring modulator has
> two inputs.
>>> The FRSX is like that two. It drops the internal oscillator and
>> accepts
>>> anything.
>>>
>>> Frequency shifting by a sine wave is 'simple' - the output is A
> + B
>>> (upshift) and A - B (downshift). If your shifting a sine wave by
> a
>> sine
>>> wave, that's simplest. 100 hz in A and 200 in b gives you 300
>> upshift
>>> and 100 downshift.
>>>
>>> Frequency shift a square wave by a sine wave, things get a
> little
>>> trickier. All the harmonics get shifted by the same absolute
>>> difference. So the more you shift the more inharmonic the
>> overtones
>>> become. It sounds weird. Also, downshift by enough and
> you get
>>> 'harmonic inversion' - the fundamental is at the high
> frequency,
>> and the
>>> overtones are fractions (not multiples) of the fundamental.
>>>
>>> NOW - shift a square by a square. You get lots of things
> going on.
>> I'm
>>> not familiar enough with it to go into it, but there must be a lot
>> of
>>> frequencies flying around in there.
>>>
>>> I don't know why it would be so much more money - it might
> have
>>> something to do with level compensation.
>>>
>>> Anybody else care to comment?
>>>
>>> vtl5c3 wrote:
>>>> Last night I was perusing my Serge catalog and noticed
> that
>>>> there were two versions of the Frequency Shifter. The
> second
>>>> version (FRSX) caught my attention.
>>>>
>>>> Here's what it says about the FRSX:
>>>>
>>>> "The basic unit features a built-in oscillator .... Available at
>> a
>>>> higher cost and on special request is a version which
> accepts
>>>> any external shifting signal. This version may be of interest
> to
>>>> musicians wanting to shift the sound of one instrument by
>>>> another, say the flute by a tuba....."
>>>>
>>>> Does anyone know how the Carrier input is designed? Is
> there
>>>> a pitch to voltage converter that is used to convert an audio
>>>> signal to drive the FS? The catalog is a bit vague as to how
> the
>>>> module works.
>>>>
>>>> Romeo
>>>>
>>>>
>>>>
>>>> To unsubscribe from this group, send an email to:
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>>>>
>>>> Keep on Patchin'!
>>>>
>>>>
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>>>>
>>>>
>
>
>
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> Keep on Patchin'!
>
>
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