Frequency Shifter (was: Re: [sdiy] Electronotes, op-amp substitution, thru-zero BODE???)

[JH.]

> I checked Jurgen's site, and indeed you are right, it is all there, just
too
> much of it!  I think I counted like 9 different circuits that I guess
would
> all have to be transferred to PCB.

Really, you don't want a pcb for this. (Unless you plan to put it into
production commecially, in which case we should talk about it anyway 8-) )

Just do it like I did: Use plenty of Veroboard area and solder the
components
such that the lay out reflects the topology of the *schematics*. That's the
secret to easy troubleshooting as well.

BTW, I don't think you really need a thru-zero VCO for a Frequency Shifter.
It's more important that your VCO can go down to very low frequencies
(<0.1 Hz), for these special chorus / infinite phasing effects.

I heard the original Bode has problems to do this. I never played with one
myself,
but I can see that this would be a typical problem of the BFO concept Bode
has used.

I'm working on a new Frequency Shifter, BTW.
This will not have a TZ VCO.

I think Thru Zero FM is a lot more useful for VCOs in Synthesizers than for
frequency shifting. With a FS, you can emulate a certain amount of TZ FM
by _shifting_ a VCO output signal down below zero, even though the FS'
own oscillator frequency doesn't go thru zero.

JH.




 The odds of me getting that right are
> about a million to one.
>
> I think I'll just take my Oakley Equinox and paint "Bode" on the front
panel
> ;-)
>
>
> -----Original Message-----
> From: owner-synth-diy at dropmix.xs4all.nl
> [mailto:owner-synth-diy at dropmix.xs4all.nl] On Behalf Of harrybissell
> Sent: Saturday, January 14, 2006 6:12 PM
> To: phil macnutt
> Cc: synth-diy at dropmix.xs4all.nl
> Subject: Re: [sdiy] Electronotes, op-amp substitution, thru-zero BODE???
>
> I see you like your projects BIG...
>
> Yes, you need a thru-zero VCO, and some phase splitting filters
> (that are not simple) and a couple of good multipliers.
>
> I believe everything can be found at Jurgen Haible's site.
>
> He likes his projects BIG, too...   :^P
>
> H^) harry  (who likes his projects BIG too... but does not need freq
> shifting
> THAT bad... :^)
>
> phil macnutt wrote:
> >
> > Howdy all,
> > I'm rather interested in somehow figuring out a way to build a Bode/Moog
> > frequency shifter clone of some sort, but I don't understand the guts of
> how
> > it works.  Is the "thru zero VCO" the basis for this famous module?
Would
> > anybody care to comment on the possibility of building one?  I'm not
> looking
> > for an exact clone, but something that has the same basic functionality.
> >
> > Ten minutes of googling turns up the following info:
> >
> > 1.      Encore says they sell one for $389 USD, but 1)an email sent
> bounced,
> > and 2)I'd much rather build one at least from a kit/blank PCB
> >
> > 2.      On Magnus' website there are links to the Moog schematics, but
the
> > links are dead.
> >
> > 3.      Two folks I found on the web have built their own (names
withheld
> > since I don't personally know them), but no PCBS available.
> >
> > 4.      Analogue Systems sells one for about $1,400 (USD)
> >
> > For me, I guess the ultimate goal here is to somehow wind up with a PCB
> > layout and a list of components that are readily available.
> >
> > So, any help or advice would be most appreciated.
> >
> > Best regards,
> > Phil
> >
> > -----Original Message-----
> > From: owner-synth-diy at dropmix.xs4all.nl
> > [mailto:owner-synth-diy at dropmix.xs4all.nl] On Behalf Of Dave Kendall
> > Sent: Saturday, January 14, 2006 6:41 AM
> > To: synth-diy at dropmix.xs4all.nl
> > Subject: Re: [sdiy] Electronotes, op-amp substitution, thru-zero
> > oscillator...
> >
> > >> i'm also looking at the thru-zero VCO... pretty complex project,
> > >> but i'll never be buying one from cyndustries... any of you
> > >> oldtimers ever build one of these beasts?
> >
> > I found this. Doesn't look too complicated......
> >
> > <http://www.edn.com/article/CA341451.html>
> >
> > Cheers,
> >
> > Dave
>
>