4011 Digital Ring Mod Circuit Snippet(s)

[frequencycentral]

I found this little circuit in one of my notebooks from many years ago. I copied it from an old analogues synth schematic, can't quite remember which one, but I think it was either the Octave Cat or the Teisco S110F, both of which were designs heavily influenced/copied from the ARP Odyssey. The Odyssey has a releated ring mod, but only using two 4011 stages. I certainly breadboarded this circuit years ago and remember it sounding good with synth oscillators as the x and y inputs. Being a digital ring mod the output is square wave only. To adapt it for guitar use it would need some caps in the audio path, and maybe some signal 'conditioning' too. I've gonna try it again soon (quite excited to have 'rediscovered' it!)...........



There seem to be quite a few different 4011 ring mod schematics about. Here's another I found in my archive:

[Taylor]

The second one is used in the MS20. Since it's "snippet-ish", perhaps Tim's Square Wave Shaper would be a good front end?

My experience with NAND ring mod on guitar was that the carrier is not at all nulled. This works in synth stuff since both oscillators will usually be moving. In a guitar app with a static osc. this might not be as fun, but I could be wrong that the ideas above will have the same issue as my previous experiments.

[earthtonesaudio]

The first one is essentially an XNOR and the second is an XOR.  The first one could possibly be made more interesting by making the ratio of the two output resistors (100k) unequal or variable.  As drawn it just has two possible output voltages but by making those resistors unequal you get 3 different possible output voltages.

[frequencycentral]

I was wondering how it would sound as an addition to an Uglyface. soggybag has an Uglyface mod on his site where he's added a mix pot between the output of the 386 and the output of the 7555, you could use the 386 and 7555 outputs to feed the x and y inputs. That might be interesting, as then but signals would be moving. But as it's the Uglyface, maybe you wouldn't notice......

[vendettav]

that square wave shaper does look promising, is it 2  LM386 in there??

[Taylor]

No, those are opamps.