Just wondering in anyone’s made a kind of 2:1 VCO with this chip. I was thinking of doing so as a nifty space saving and functional little bit of kit. Any thoughts?
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Very interesting!! Thanks.
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You could also thicken this up with a CD4040B 12 stage binary ripple-carry counter. 12 stage is kinda overkill, but whatever.
What you do is setup one 555 as an astable circuit, then feed the output (pin 3) of the 555 into pin 10 of your ripple counter. Then, the buffered outputs (Q1-Q12) will then give you 12 octaves worth of frequencies.
Combine this with a op-amp mixer, and you got a mighty chungus of a voice. What might be more musical though, is having a 1 pole, 12 position rotary switch to select which buffered output to use, effectively selecting which octave you want the voice to be.
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Ooooooo I do like me some chungus sounds for the thick vibes.
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555, CD4040, I’m glad to hear all these names, also the CD4017 
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Can’t leave out the multi-talented 4069 while we’re on the topic!
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556 and 566 are two different things, though…
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I didnt even know the 566 existed. What a world!
Datasheet for fun:
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Hmmmm that chip 566 seems like an easy guy to mess with for a minimal handheld noise machine just add a filter or something.
oh yes of course, really sorry, a reading error !!!
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No worries, that one was new to me. I just had some trouble parsing the schematics until I noticed the difference 
Unfortunately it’s no longer manufactured, but since it appears in DIY schematics you can find things labelled NE566 on ebay (mostly from European sellers it seems, so some might actually be NOS, otherwise the usual caveats apply). Rod Elliott discusses it briefly here, and provides some simple alternatives:
https://sound-au.com/project162.htm
(but note that he’s talking about audio engineering use, so those designs use linear CV, not V/Oct).
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So did someone change the title? I could have sworn it said 556 (which is a widely used dual timer/oscillator, still in production) and not 566 (which is a single voltage-controlled oscillator, no longer in production).
(Or was this another case of the “let’s meet Wednesday the 5th of May” issue, where half will show up on the 5th and half on Wednesday.)
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I too am almost sure it was 556 in the title!
otherwise my answer is no longer an error 
but i don’t think really
I’m 99% sure I titled this 556.
I changed the title again. He meant 556. We should avoid changing titles unless they’re truly inaccurate.
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I definitely assumed 556, which is basically a couple of 555s in a single package.
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