[sdiy] frequency shifters...

[Peter Grenader]

The way I understand it, the Bode frequency shifter accepts two external
signals for both the x and y from which you derive the SSB (single side
band) modulation.  I have not heard the Analgoue Systems version, but I'm
sure it's superior to the original in that it offers much more voltage
control.

The Doepfer has but one input.  The second signal is supplied by an internal
oscillator.  I own one of Doepfer's units.  After hearing their oscillators
and filters, I must admit I have been a bit nervous since to acquire
anything they make for processing or generating audio.  If you look at my
system you'll notice that 90% of my Doepfer gear is control voltage
generating only.  A matter of that, outside of the frequency shifter, the
only things they make that handle ausio is a phasor and a panner. I must
say, I was pleasently surprised by their frequency shifter however.

It does what it's supposed to, the signal it generates is musical and
variable.  My only objections is there is a certain amount of bleed through
of the internal osc to the outputs - it's not fully attenuated.  If you have
nothing going into it (no input waveform) and you listen to the output,
instead of hearing nothing, you hear the internal oscillator.  Just
slightly, but enough to make for problems in bits of silence you may want
inb etween sound events processed by the beast. What this means is it's best
to run your signal through the frequency shifter BEFORE the VCA.

For the price though, you can't beat it.

P





> I agree with you Harry. It seems to be way beyond my limited experience. I do
> absolutely love the sounds created by frequency shifting, but building myself
> is out of the question. Now for the question that all this leads into... what
> is the difference between the Doepfer and a Bode style frequency shifter?
> 
> thanks all.'
> 
> e. schultheis