Guitar Effects Pedal Multiplexing

I’m starting a project using multiplexers to select and order various guitar effects pedals controlled by an Arduino. I am building this out of pure curiousity for a friend of mine who is an avid guitarist and musical guru. My ignorance convinces me that something can be done until proven it can’t and I’m retired so that gives me ample opportunity to things like this for the pure joy of the experience. When I started this, I didn’t know a gas pedal from an effects pedal my knowledge of electronics is extremely basic.

To date, I have used 4 - 16:1 multiplexers TI 74HC4067 (actually on Sparkfun break out boards) connected as shown on the attached drawing to select from 3 different effects pedals in all possible combinations. I’ve been controlling the muxes with jumpers to 5v on the S0-S3 pins. Most problems with the initial concept were just poor workmanship on my part but it seems to control and pass the signal without distortion or other problems. I added the 1uf capacitors as an attempt to eliminate some low signal “ticking” on a tremolo pedal that I am told would be eliminated with a noise gate but I’m not sure they are effective although the tick got much weaker.

My next step is to bring the total number of muxes to 13 and the total number of pedals to 12 and see what happens. I was able to find some dip forms which are much friendlier to work with but they are coming direct from China so we’ll see if they ever get here. (They just did so now to see if they are any good).

Then will come the programming of the Arduino Mega and I’m going to be looking for major help in that department because I really don’t want to learn all that programming business for one project. The idea of the ulitmate configuration is to have the pedals hard wired into all of this in some sort of a rack with a remote foot controller for a performer to select scenes as predetermined from a phone or tablet via bluetooth. The goal is to have the user make the scene configurations, selections and for the connections to be hard and reliable. Showbiz stuff I guess.

The was a similar project written about here by jtbennet about a year ago. The attached schematic was drawn on a spreadsheet so I had no way of showing the junction points but the idea is that each channel is connected to the same channel of the other muxes. I’ll keep posting my progress and look forward to sharing your wisdom.

Guitar System Thing - CIRCUIT 2.pdf (28.2 KB)

What is a "dip form"?

I think it means dual inline processor. To me, its a chip the size of half a pinkie vs the type you can buy from TI or Sparkfun which are half the size of a pinkie nail and way too small for me to solder. I’ve been using the TI chip on a Sparkfun breakout board.

Well a DIP (dual inline package) typically has pins on 0.1 inch centers to match a socket or through hole on a PCB. Your description doesn't sound like that.