Guitar Signal Processing and the Arduino

Projects General Guidance
1

Hey,

So what I'm trying to build is basically a circuit that first takes a guitar signal that goes to the Arduino Uno with an IOT shield that connects to a smartphone where you can select one of two channels, i.e., basically the signal goes into the arduino and is sent out through one of two ports, and the first output goes to a simple homemade preamp guitar pedal with transistors and the second output goes to a tube pre-amp (based off the Valvecaster) and then the output from both of these (whichever one is used) goes to this -

And there are a bunch of effects applied onto the signal and then sent out to a guitar amplifier.

So here are my questions -

  1. I am no expert on guitar pedals but I do understand that the arduino can only read guitar signals between 0-5V, so my question is, what am I doing wrong in this design/ or what do I need to add to make this work the way I want it to?

In the first step, to select the channel, I would need to add a small JFET/ transistor circuit similar to this -

http://interface.khm.de/index.php/lab/interfaces-advanced/arduino-realtime-audio-processing/

Is this right?

If I already amplify the signal, such that the arduino can recognize it, then will the purpose of the tube/solid-state pre-amp that comes after be defeated?

  1. Once the signal comes out of whatever pre-amp is selected, it goes into the pedalshield for adding effects, but the pedal shield has a pre-amp in it to amplify the signal. So, what would happen in this case?
    Do I need to remove the pre-amp in the pedalshield, to avoid damage? Or will it be scaled accordingly?

  2. If all of this is wrong, I basically need to build a pre-amp channel selector using an arduino uno and a smartphone (Solid state channel or tube channel) fed into the pedalshield for effects. How do I do this, if the above design is wrong?

Thanks in advance! Any help would be appreciated!

2

What is the desired function? Does the smartphone control the audio routing or does the Arduino? Is this a manual or an automatic selection? If automatic, how do you want it to work?

3

aarg:
What is the desired function? Does the smartphone control the audio routing or does the Arduino? Is this a manual or an automatic selection? If automatic, how do you want it to work?

The smartphone basically has 2 buttons - Channel 1 and Channel 2. If I press Channel 1, then the arduino should route the signal to the solid state pre-amp and the tube if I press Channel 2.

4

The simple solution is a relay.

5

Could you please elaborate? Would this relay work with the circuit as I described?

6

shadow12348:
Could you please elaborate? Would this relay work with the circuit as I described?

Why would I tell you it would work with something you didn't ask about? :0 Of course it will work. You just need to switch the relay with the Arduino.

7

Didn't think of this before. Thanks so much! This helps a lot!

Just one more thing, once I switch with the relay and send the guitar signal to one of the pre-amps, the amplified guitar signal goes into the Pedalshield which uses and Arduino Due, and the Pedalshield amplifies the signal again, will this damage the pedal or can I just use it as is?