The Due has 12-bit ADCs & DACs. That's probably 'good enough' for electric guitar but I'm not sure about the cello. If you end-up adding an ADC & DAC it might be better to use something else.
What you're trying to do doesn't take lots of processing power. However, 16-bits at 44.1kHz requires 88.2 kilobytes for each second of audio, so the memory requirements can add-up. (12-bit audio is going to require 2-bytes per sample too unless you figure-out a way to "pack" the data.)
Save the file on a SD, in .wav format. Is it possible?
I assume you don't need "permanent" non-volatile memory? If this is a self-contained device, an array in RAM might be better than a WAV file. (I don't know if you an add RAM to the Due.)
Play back the recording immediately after recording it,through an external DAC and have the possibility to play/stop it.
That should be fairly simple.
Play 2 or more recordings simultaneously
I have no idea if you can read/open two WAV files at once, since you don't have an operating system.
But digital audio mixing is easy... It's simply sample-by-sample summation. Although in practice you have to scale-down the data before or after summing to prevent clipping (distortion) so it's actually an averaging process. You'd do the same thing if you want to digitally mix the loop with live sound. (Analog mixers are built around a summing amplifier.)
for my electric cello.
Thats new to me... I've only seen electric violins...
I assume you don't need "permanent" non-volatile memory?
I'd like to save the file on a non-volatile memory, like an SD but i don't know if the Arduino is fast enough,
and if there is a library that allow me to save and read file easily.
The Due has 12-bit ADCs & DACs. That's probably 'good enough' for electric guitar but I'm not sure about the cello.
I konw that the Due has 12-bit ADCs & DACs but I do not know the quality of the final sound.
Now my first problem to solve is save files on a SD and play them whit the PC to test the quality (for this I have to save in .wav). Any idea?
