advanced audio recording
Spartan 3 music workstation
   Full Stereo
Digital IO Bus

128x3 oscillators

256 voices

128 midi channels

96 kHz
Audio DSP

Spartan 3E Development System
FPGA SYnthesizer with Spartan 3
Fully FPGA-powered synthesizer

A Xilinx Spartan 3 FPGA board is used for sound synthesis and video generation. 2 mouse ports (serial + PS/2) are available for graphic control and synthesis control. Also 2 MIDI-controllers can be attached. The DIY-Controller works with standard 230kBaud, which is 7 times faster than normal MIDI (31kbps). A standard Controller from Döpfer is attached to MIDI and studio gear. AD-Conversion is performed by a professional device from Mindprint:


Music Box / MIDI Engine

MIDI music engine in VHDL

The Music Engine produces MIDI-like information, based on pre defined rhythm and tone patterns which are kept in a memory. The tone notes are copied/doubled according to the ARP pattern, compressed in loudness and modified by the ADSR-module end then sent to the synth module synchronously. 255 Tone Levels = quarter Notes covering 127 MIDI Notes are available.

The arpeggio module uses adjacent MIDI channels to produce MIDI echo rather than audio echo. This is possible with a very high time resolution using internal high speed MIDI creating short reflections similar to room reverb. For the slower (normal) arpeggio the channels can use different parameters for the voices.

MIDI Controller with PS/2 keyboard

MIDI input / workstation control with PS/2 keyboard

Synth Engine

1024 voice polyphonic music synthesizer module - Jürgen Schuhmacher

The synthesizer engine takes the MIDI notes and produces audio signals for each midi channel from generic functions, tone banks, or DDS-based. Wave table is planned. The Synthesizer operates totally pipelined and with 50MHz clock speed and processes 128 from 256 possible MIDI channels, has 3 oscillators / wave generators and 256 voices polyphony. Listen to the demo XILINXFPGASYNTHESIZER.WMA

DSP Engine

basic fpga sound processor in vhdl - sound processor for the 1024 voice polyphonic music synthesizer

Also a DSP Engine performs audio processing, compression, limiting and distortion can be loaded into the FPGA system.

Graphical Spectrum Analyzer

audio spectrum analyzer created with spartan fpga on a 1920x1020 TFT screen

Together with the VGA output of the Spartan board, a FFT-like algorithm is used to perform a simple graphical band analysis for 16 frequencies with a 3:2 ratio of distance in between (central frequencies: 20, 30, 45, 68, 100, 150, 225, 340, 515, 770, 1150, 1730, 2600, 3900, 5850, 8750).

synthesis control with FPGA oscilloscope

 Sound Design and Sound Control can be supported by virtual wave control using a minimal oscilloscope function in the Spartan FPGA. Because of the limited resources, FFT is only available with a second board.

Click here for the former Version (Spartan 2)



© Jürgen Schuhmacher 2006