This looks like an awesome project and coincides nicely with my desire to create a similar device. I got an Arduino board a few weeks ago and have been playing with it, getting familiar with the environment. I like it a lot.
What I'd like to do is make a preamplifier, controlled with the Arduino via buttons and eventually a remote. I'll be starting some prototyping this afternoon and have some shift registers (595 for output, 4021 for input) and 3-wire LCD using the LCD3Wire library and 4094 shift register.
My goal is to have:
- 4 inputs - 1 analog, 3 digital - as inputs to the preamp, the digital inputs going through a DAC (external at the moment, through my LD DAC_1, but eventually through an internal or external Opus DAC). Digital inputs would be USB (with USB > SPDIF), coax, optical (with TOS > SPDIF), input selector would switch between the SPDIF inputs and send that through to the DAC which sends back the analog signal via a 'loop input'.
- PGA volume control with a rotary encoder, with the Arduino saving volume level / mute state in eeprom.
- Multiple outputs (2 or 3) with the option to bypass the PGA and have line level output on each output.
- e24 (or similar) power control that has mains output to plug amps into so that I can power off the preamp (by button or remote) and power is cut to the amps as well.
Is any of the code you have been working on available? It would really help me and I could contribute what improvements I can as well.
I could also help with prototyping if you need extra boards built and tested.