a jolly useful circuit in my experience, and one im pretty pleased i came up with. another nice feature is you can set the threshold so that its output sync pulses can lag behind the input slightly, which seems to give some control over colour. which is nice.
SynthPunk Sync Processor
you should probably build at least 2 of these. they accept positive or negative going sync pulses in any polarity or voltage between -12 and 12 volts and can extract a clean positive or negative trigger for the VCO’s. this means you can use pretty much any Sync Pulse generator or VCO circuit with this device. and as its basically just a comparator you can use it for other purposes within a patch too.