Saturday, November 26, 2011

Build a Mixer for Your Lunetta

Running all of the outs of our cmos to just one output is not much fun.  Let's build a mixer to give us greater options in creating wicked rhythms. I use an active mixer (op amp based) as opposed to a passive mixer (just resistors tied together).  The op amp of choice is a TL072 and the main advantage in using the op amp has to do with buffering.

Buffering in our lunettas will help bring all the various levels "up to snuff" so to speak.  Here's a drawing of the mixer in my lunetta.

There are many different designs for mixers out there as you know.  I built this one based off of a few different ideas I ran over with other builders.   This is my version of mixer number 3 on The Electric Kitchen's Mixer Page.
 I haven't run into any issues with this design and I think you'll like it too.

I've used the TL074 with similar success.

Here's the pinout of the TL072:


  1. Hey Pete. Thanks for posting this. I just found a link to it from ( ). I've built mixers for years for my modular, but will be considering this guy for my new Lunetta machine that I just started, a couple of days ago. :)

    (Richarius / formerly Rykhaard, on EM)

    1. Thanks Rich,
      I probably should have added the typical Vref stuff for the op amp but it works very well with the lunette since I'm using mostley square waves. No complicated sine waves to worry about LOL!.