Building Modular Synthesizers since 2010

8 x XOR Gates

This is a module I whipped up to do some simple Math.

It happened to have the added benefit of sounding AWESOME beyond my imagination!!!

The Schematic and the BOM are only for one 4070 chip and are only 4 x XOR Gates.  The PCB is double. The part numbers are repeated. The circuit is exactly the same so I just copied it.  When you’re planning for this board read the BOM and DOUBLE all the components (except for the smoothing cap and MTA .156 power connector).

The second connector is just there for your own experimentation. I would not install anything in that spot. It may be handy if you need to use a Dotcom or Euro style connector; or if you start fiddling around in the sandbox.

If you look you’ll notice that -15V is not connected to anything on this board.

Unfortunately this board was a quickie and a one-off, so I can’t take the time to shrink it to fit parallel behind an MU Front Panel… BUT it will easily fit behind 1 1/2 an MU panel and if you mount it perpendicular it should only be about 3 1/2″ deep.

I was playing around with transistors so with the given values the XOR out is not beefy enough to trigger the logic functions on my LogicOgic Board (It will trigger the FlipFlops).

It should be a simple matter of fiddling with the voltage divider at the outputs (using a larger value for R20, R22, R42 and R44. Try 10 K) if you want Beefier Outputs.

That being said, it plays very nicely with my VCOs and integrates with all the standard modular voltage levels.

It sounds Awesome!! Try chaining the XORs with Sub-Oscillators for Noisy, Flangey, Foldy Goodness.

Here’s a quick and dirty demo of some of the more restrained sounds you can get from it:
Mellow hook XOR 1

Here’s a sequence where the XOR Gates are screwing with the Sequence timing and the Audio:
Sequenced Cacauphony

All transistors are 2N3904

 

Here’s the Goods:

8 x XOR Gates Sch

8 x XOR Gates Etch

8 x XOR Gates TopPlace

XOR Gates wSandbox BOM

 

And here’s the whole Shebang:

8 x XOR Gates