You could always breadboard one up and test the differences between the two... ;Dabechap024 said:...there are many ways to make an oscillator...many easier ways since when the PYE was originally designed. If it was designed today I imagine it might use a 555 chip as the oscillator or they even have ICs that's main purpose is to oscillate. I imagine we can't just pull the old oscillator out and put a new one in...or could we?
Rob Flinn said:With regards to the oscillator. As far as I'm aware a 555 puts out a square wave or a triangle wave with a cap added. I'm no expert on discreet oscillators, but I think they normally put out a sine wave, which might rule out using a 555.
I think that many of these old style PWM compressors vary the mark/space ratio by changing the break point on a comparator, so that it triggers at different heights on a sine wave fed to the other input. Thus varying the mark space ratio.
It would be useful to get a scope on a real Pye to see what the signals doing in different places.
Rob Flinn said:It maybe that the oscillator is set to output a triangular wave, because that will work in the same way with a comparator as the sine wave, all be it with a slightly different response.
I know someone with a PYE that might let me get a scope on it. I'll make some enquiries.