artist: krue
compo: blockparty 2008 wildcard
title: avrsyn
website: http://krue.net/avrsyn/

comments:
The avrsyn is a monophonic 'virtual analog' synthesizer. A single 8bit
microcontroller handles all aspects of the synth, including input switch
and knob scanning, MIDI parsing, and actual sound generation. The orignal
avrsyn was a kit from Elby Designs[1], but this version greatly expands on
the numer of features. Most of the code is new, though some portions by
Jarek Ziembicki[2] remain.

A quick feature comparison:

Feature             Original                 Modified
------------------------------------------------------------------------------
sample rate         31250Hz                  62500Hz
envelope            1 A(S)R                  2 ADSR
oscillators         2 saw/square             2 wavetable
                                             (one set of wave data provides
                                              sin,saw,square,triangle)
                                             1 oscillator switchable to noise
filter              1 pole IIR lowpass       1 pole IIR lowpass
                                             1 pole IIR highpass
                                             state variable (HP,LP,BP,BR)
                                             Moog lowpass
fm                  none                     2 operator
arpeggiator         none                     adjustable rate and note length


CPU specs:
----------

Atmel atmega32
16MHz clock
$8000 bytes flash
$800 bytes ram


[1] http://elby-designs.com/
[2] http://jarek-synth.strona.pl/

