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Oscillator to "clock" cp-251 Sample and Hold circuit

Posted: Tue May 13, 2014 3:25 pm
by Plastic_Telos
Howdy.

So here's the thing. I've been using the carrier oscillator from my mf-102 into the trigger input of the cp-251 sample and hold to allow to use the circuit as a sample rate reducer.

There are two problems with this: 1: The carrier oscillator only gets up to around 8-9 khz when goosed with an expression pedal giving a narrow range. 2: The carrier is a triangle wave and, though ive been able to get it closer to square wave with some processing, it is not really ideal for the application.

So...

I'm looking for a square wave oscillator that extends well up though the audio range that i could use as a clock for the s+h. Ideally i would also be able to control the frequency of the oscillator with an expression pedal.

So far the only solution i've though of is to get down and dirty with a microcontroller but... I'd really love some instant gratification short of buying an mf-107. :idk:

Re: Oscillator to "clock" cp-251 Sample and Hold circuit

Posted: Tue May 13, 2014 6:59 pm
by nevada
Maybe an Arduino synth if you want to stay on the small side. Something from whatever Standuino is called now?

Most of the CMOS stuff (Skychord, etc.) is square wave but lower than that range.

Re: Oscillator to "clock" cp-251 Sample and Hold circuit

Posted: Tue May 13, 2014 8:31 pm
by nevada

Re: Oscillator to "clock" cp-251 Sample and Hold circuit

Posted: Tue May 13, 2014 10:48 pm
by Plastic_Telos
Hmm these could both get me part of the way there. It would be great to be able to control the frequency with an expression pedal for aliasy sweeps though. Side note: I really want a microgranny now.

Re: Oscillator to "clock" cp-251 Sample and Hold circuit

Posted: Wed May 14, 2014 8:42 am
by Glenouille
What about something along these lines?
http://www.eleccircuit.com/triangle-wav ... verter-ic/

Re: Oscillator to "clock" cp-251 Sample and Hold circuit

Posted: Wed May 14, 2014 11:27 am
by Plastic_Telos
Ooh that looks like it could work. Does anyone know if I would have compatibility issues with that? voltage etc.

Re: Oscillator to "clock" cp-251 Sample and Hold circuit

Posted: Wed May 14, 2014 5:00 pm
by sonidero
The LFO on the CP-251 is clocking the S&H... If you plug an expression pedal to the LFO Rate, I used the Moog, and then out of the S&H out 1 to the Mixer you can change the pitch that way... Also I my not understand what you are doing... :idk: