Pulse Frequency Doubler (corrected)

[octafish]

This was originally fed by a 500Hz squarewave oscillator.
I don't know if it'll work for sine waves but adding it after a square wave shaper or hardclipping silicon diodes might get her working. Cap values could be tweaked and converting it to 9V single power would make it easier to incorporate in existing circuits. Its somewhat reminiscent of the Foxx Tone Machine. Anyhoo have fun.

PS. the filename is mispelt Pulsefrequncydoubler I'll probably repost later, but for now, live with it.
edit: this is how it is meant to look

[Processaurus]

It looks like the direct connection to ground after the 56nF cap off the emitter would short out the signal on that side, making the circuit a half wave rectifier, rather than a full wave rectifier/ octave type circuit.  Plus the resistors off the 56nF cap on the bottom look much too small, if all they're doing is acting as pulldown resistors after the cap.  A 1 Meg resistor to ground after each 56nF cap should work fine, I think.

[niftydog]

any more info on this? I'm doing a circuit simulation and it's ain't doing much at the moment. You call it a pulse freq. doubler, but then say squarewave... so is it pulses or a squarewave?

(just the claritfy, my definition of a square wave is 50% duty cycle, completely symmetrical whereas a pulse wave can be just about anything else!)

[Pedal love]

You have a phase splitter, so make the collector resistor 4.7k and lose the 2.2k-1k resistors. Nice!

[octafish]

Well I have no real information about this piece of circuit except it does double the frequency of the oscillator when constructed on my 130-in-one breadboard. The book I got it from confirms it is a phase splitter and now  looking at (crappy) drawing I see that the correct value of collector resistor is 470R and there should be a 4k7 resistor to ground from the to diode. I'll fix 'er up and update.

edit: There we go. hmmm looks like those two pull down resistors are meant to match. The odd ball 2k2 plus 1k arangement would apear to be because the 130-in-one only has one 4k7. I am yet to put this into a circuit but it looks promising.

niftydog, it'll probably work with other pulse waves but was originally implemented in a square wave, also that is what the project was called in the book. I think of square waves as basic digital sine waves. but thats my problem not yours.

[Pedal love]

That looks fine. This is the approach used in many octave doublers including Roger Mayer's Octavia. It presents a signal that is the same size, from both pos/neg sides, to the diodes for rectification. It should sound right.pl

[niftydog]

I think of square waves as basic digital sine waves. but thats my problem not yours.

It's just a matter of opinion.

[niftydog]

ok, sim is up and running and working well. If anyone want's some specific things tried on the sim, let me know.

Regarding the square wave / pulse wave thing, its actually taking the transition of the wave and creating a peak. So in a pulse wave you don't end up with evenly spaced peaks - Could be interesting!

Cool circuit octafish, thanks!