I would like to do some switching of the audio signal on-board an electric guitar, direct from the pickups to route the signals.
I would command the switches from an Arduino.
I will need 15 SPST switches to handle tiny analog voltages maxing around 1V, but more typically 120mV.
I have considered reed relays, but then came across "analog switch IC" and thought that would be more efficient and take less space and power. Also, I fear that the magnetic fields in the relays would create lots of parasite noise, but maybe that is not the case? The reed relays are quite big, too.
Honestly, I have read all about analog switch IC's all over the net, but they remain mysterious to my novice level electronics knowledge.
Can anyone suggest a 4 SPST analog switch that would be able to turn on/off that kind of signal? I would guess that low on-resistance is important, but I don't know how low is low? 100ohm, 10 ohm, 1 ohm?
Also, how would these be controlled by the Arduino? SPI ?
How many Arduino Pins would be involved to control 15 SPST switches? would I have to add a shift register as well?
The rest of my circuit requires 3 6-channel digital potentiometers that are controlled by SPI. So 3 pins are taken... Ideally, I would like to control everything by SPI if possible...
Any advice, suggestions or even an answer would be a huge help to me!
Thanks so much for this great forum!