Some time ago I have published the wireless system for electric guitar based on ATmega microcontrollers, RFM70 radio modules and CS5343 ADC: http://wzab.cba.pl/STARE/wireless_guitar_system/index.html
It seems to me, that ESP8266 may be used instead of ATmega88 and RFM70 in the transmitter, eliminating also the need of dedicated receiver (as the sound and control data will be transferred via WiFi to the computer running the virtual guitar processor/amplifier).
Of course TCP over WiFi network will introduce certain (fluctuating) delay, but alsa_in module can easily filter it out at cost of certain latency (I've already tested it, checking possibility of building of such a system with Raspberry Pi: https://github.com/wzab/raspberry-pi-guitar-system-v1 ).
The ESP8266 can provide much better audio buffering capabilities than ATmega88, and use much less power then Raspberry Pi. It can also handle switches/potentiometers via I2C or SPI connected DIO and ADC chips.
However before attempting to implement such a system, I'd like to know if there is any good documentation about using of I2S capabilities of ESP8266?
I'll appreciate any sugestions and comments,
Regards,
Wojtek