The deMIDulator is a MIDI-controlled audio synthesizer, lo-fi audio sampler and PIC microcontroller development platform. ...
http://badhandshake.com/demidulator/index.html 8-bit digital synthesis
Compact design
Simple user interface
Three sound modes: Sine, Square, Sample
Three playback modes: Polyphonic, Sustain, Monophonic
4 note polyphony
Sample mode allows user to record custom audio sample to use as playback sound (max length = ~2 seconds)
Line-In and Microphone(PCB or external) audio inputs for sample recording
4-conductor headset jack provides both audio output and microphone input for use with iPhone-compatible headsets
MIDI output jack functions as MIDI-thru
Analog volume and frequency cutoff controls
MIDI control of Waveform Select, Mode Select, Pitch Wheel, Modulation, Attack Time, Release Time
Firmware upgradable via MIDI SysEx
Flexible power options: AC adaptor, 3xAAA batteries, ICSP header
Socketed microcontroller and EEPROM ICs
Small prototyping area on PCB
Sweet laser-cut wood enclosure with latching battery panel
Open source design files
http://derekenos.com/deMIDulator_overview.html