turning guitar into a skinny pulse?

[loss1234]

Anybody have any ideas on how to do this?
I would like to be able to use the guitar to things like create triggers, and also for F to V i need a skinny pulse.

One route i was looking into was first using an octave down, so say taking the output of a 4024 which IS a good clean square but is not nearly a skinny pulse.

So i guess i wonder if it is easier to do this with an out from the CMOS or straight from a squared guitar. Either way, I tried comprators and had little luck there. so any ideas would be great!!

thanks so much

[StephenGiles]

It's there in the EH Rackmount Guitar Synth........one of the VCOs has pwm.

[loss1234]

hold on...do you mean i would have to build ALL the associated circuitry to get that far?

or do you mean just take a look at the vco section?

my memories of that EH design is it took my 2 giant breadboards just  to get to the end of page one!

i will take a look though


i  was hoping for a simple solution


thanks

[Gus]

look up edge detectors and monostables.  You want to detect the edge and maybe the direction the edge is going + or -.  detect the edge then fire the monostable set to a PW.  use a square type wave

I have not done this for an effect but this is how I would start if I wanted to.

Also look in the "Art of Electroincs"

http://www.physics.ucla.edu/demoweb/demomanual/electricity_and_magnetism/ac_circuits/rc_integration_and_differentiation.html

[Andre]

A couple of years ago I made a sort of what I then called a fundamental extractor, but is in fact a square wave shaper.
It is a part of the Boss OC-2 octaver.
I also made a PCB for it:
You can find it here

You could use the output to trigger a monostable multivibrator to generate a small pulse with each rising or falling edge.

I used this principle to create an octave up circuit  by triggering one Multivib with the rising edge and a second one with the falling edge of the output of my extractor.
The output pulses were added together.

In this thread you can see a scope picture of the output.
Unfortunately I was not able to finish my circuit in time.
In fact, I still have not finished it. 

[gez]

There's a little circuit in one of Owen Bishop's books that is quite ingenious.  How well it works, though, is another matter.  He basically sends a square wave to the two inputs of an XOR gate.  One chain, however, goes via a couple of unbuffered CMOS inverters in series (non-inverting).  Due to the sluggish nature of the inverters, there's a slight delay, so you get a tiny slither at the output of the XOR.  You might just see hairlines at the output of a scope...is that short enough??

[gez]

PS  The circuit acts as a doubler, too.  So you'd need to take the division down to the next rung if you want the output to be the same frequency as the input.

Not sure how clean the output would be, either.  Edge-detector would be the safe bet (as mentioned).