some old e&mm synth-diy schemos

[synth_ollie]

not the best quality but maybe useful anyway....

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graphicoscillator.jpg
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sawtoothprocessor.jpg
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realtimefmharmgen.jpg
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[Peake]

I can only comment about the third item; it's a typical BBD delay line with the input tapped off prior to the BBD input, and used to modulate the clock. This can be done with existing delay lines. It's equivalent to the technique of taking oscillator output and also modulating filter Fc as well as running the oscillators into the filter's audio path. (Try splitting filter or VCA output and running it back into the filter or oscillator control inputs, as well.)

I don't know what it will sound like with a BBD. Odd how there is no buffer after the 571. Is it not like the 572? I was just tracing out a BBD signal path the other day and found that an audio tap shows nothing at the 572 output (current, not voltage?)

Edit: The first item has ye olde 4024 divider, which was my first DIY in high school. It outputs several octave down divisions.

[Coriolis]

Thanks for those! They look nice and simple to build.

C

[Norman Phay]

I actually built that sawtooth processor back in the day. As I remember it actually sounded quite interesting, but was a bit noisy (the noisy part may have been my useless constructing skillz back than, though)

I was going to build the graphic oscillator, but never got round to it.

"Electronic Soundmaker and Computer music" had a few circuits as well, including a mighty 16 x 4 sequencer that I never got working. I still have the panel and the case I made somewhere.