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Full Stereo
Digital IO Bus
128x3 oscillators
256 voices
128 midi channels
96 kHz
Audio DSP
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Spartan 3E Development System .
![FPGA SYnthesizer with Spartan 3](../images/spartan3efpgasynthesizer.jpg)
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:
![MINDPRINT AN/DI](../images/andipro.jpg)
Music Box / MIDI Engine
![MIDI music engine in VHDL](../images/midiengine04.gif)
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](../images/miditastaturkeyboardps2.jpg)
MIDI input / workstation control with PS/2 keyboard
Synth Engine
![1024 voice polyphonic music synthesizer module - Jürgen Schuhmacher](../images/synthesizerstructure.gif)
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](../images/audiodspschem.gif)
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](../images/grapheqanalyzerspartan.jpg)
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](../images/spartan3audioanalyzer.jpg)
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)
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