This'll get you folks thinking

[Mark Hammer]

I was just looking through James Patchell's web page for something else and stumbled onto his CV splitter idea.  Neat!!

Take a peek and, as Jimi would say "Just let your little mind float".

http://www.oldcrows.net/~patchell/misc/splitter.html

[donald stringer]

I am just curious, what are  cv used for ?

[Jason Stout]

I think it would be fun to feed Vref with the output of an lfo and send the top and bottom portions of the signal off to be massaged by some other circuitry before finally bringing them back together. I honestly wish I had the time..Cool circuit!

Jason

[C Bradley]

I'm thinking that you could use that circuit for an octave up effect, if you connected two diodes to the outputs in a fullwave rectifier circuit. Then I'd want to change the two second stages to add a little gain, and use an opamp mixer at the output to give me one output with the octave and the fundamental (original) signal together.

Just another idea I might have to explore.  :roll:

Chris B

[amz-fx]

I was just looking through James Patchell's web page for something else and stumbled onto his CV splitter idea.  Neat!!

I've seen this circuit before... maybe in one of his old Polyphony articles, but it is still interesting. Thanks for bringing it back up!  I can see a couple of cool new uses for it...

This page of his goes into more detail:

http://www.oldcrows.net/~patchell/archives/idealdiode.html

regards, Jack

[moosapotamus]

Way cool!

I guess it's implied, but those opamps (i.e. TL07x) should have a bipolar power supply, like +/-9V, right?

Also, might this work as an inverter on the Small Stone (control voltage) LFO?

Thanks!
~ Charlie

[gez]

I guess it's implied, but those opamps (i.e. TL07x) should have a bipolar power supply, like +/-9V, right?

Yeah.  I've been messing around designing a single supply version of an ideal diode FW rectifier and it's a tempremental little sod!  Still, bit by bit I'm ironing out the creases  

[Paul Perry (Frostwave)]

In industrilal electronics (old-school) where a single supply was used, the LM3900 was a workhorse. Here's a site that might inspire: the Serge waveshaper!
http://www.geocities.com/SoHo/Museum/4459/theory/sergewsh.html
(I havn't built it myself. No, you can't use anythig instead of the 3900!)

[gez]

Thanks for that Paul!  If I can't get any joy from what I'm building at the moment I'll have a crack at that.  

The problems I'm having are that I've made the gain frequency dependent and I think the tolerances of the caps aren't tight enough - the amplitudes of the peaks are different (time for some trimpots!).

There's also something weird happening in the first stage. I think one of the Ge diodes is leaky and mucking things up.  It works mind - just not a 'precision' rectifier.

[brett]

This circuit might be useful in ring modulators, where non-ideal diode behaviour strongly limits the performance of the circuit.  Only hitch is that you'd need at least two, maybe four, which would greatly complicate most ring mod circuits.

[Paul Perry (Frostwave)]

Brett, I think it is the non-idal diode performance that makes a ring modulator. To get the best effect, using a transformer/diode ring modulator, you want the dides to have as close to a square law response as possibe.