Rolls "Bottom Feeder" ciruit!

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Hmmf. Interesting circuit, never really looked at Sub-Harmonic synthesizers before...

First glance, it looks like there's a divide-by-four circuit in thebottom right corner (2 stages of a 4013). the output appears to 'chop' modulate a signal which is then low-pass filtered (to get rid of the 'Buzziness' presumably) and fed to the seperate sub output. The pre-conditioning before the feed to the [÷4] circuit appears to have a state-variable filter (bandpass?) in the top right hand part of the schematic. The upper left part of the drawing appears to be some general shaping.

Am I reading that right?

Keith
 
I was told years ago that the dee-bee-eks ckt went like this:

buffer/summer -->BPF (I think maybe 50Hz to 120Hz) -->clipper ckt (makes it into a square wave) -->555 timer as a divide by two -->mixed back in with original signal. Seems crude but interesting. If I remember correctly, a friend had one and took a dance thru it with an O'scope so I could see.

When you understand what the box intends to do, you understand the range of the BPF. Processing freqs below 50 makes dangerous stuff...it might not have even gone that low.

Peace!
Charlie
 

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