[Fpga-synth] Digital Waveguide

[Scott Gravenhorst]

Hi List,

I had success today, so I gotta tell someone...  

Relative to the Spartan-3E Starter Kit:

I've been working on implementing conceptual bits for a digital waveguide
synth (for plucked strings, drums and bell/gongs).  I've just now gotten it
working in an FPGA design as a single waveguide MIDI "plucked" synth.  

This was initially inspired by the Terrormouse college project.  After
reading a bunch of Julius O. Smith stuff, I decided on using a 2 RAM (left
and right going) system with a filter and inversion at each end of the
delay line.  The "pickup" is movable.  The RAMs are 2048x18 currently
implemented in block RAM.  (a single 256 location RAM was used in Terrormouse).

I'm very pleased with what I see on the oscope.  I will be making and
wiki-posting some sound samples once I get that far.

If after some listening, I feel that making a "harp" of these waveguides
would be musically useful to me [probably, from what I've heard so far],
then I will move to the next stage - incorporating the 64 Meg DDR SDRAM to
use as the storage for each string.

My goal is to create and service 12 waveguides minimum with hopes at 24. 
Each waveguide will be 16384 locations long (double sided) and 16 bits
wide.  This should give more than 5 musically accurate octaves (at less
than 5 cents away).

-- ScottG

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-- Scott Gravenhorst
-- GateMan I - Xilinx Spartan-3E Based MIDI Synthesizer
-- FatMan: home1.gte.net/res0658s/fatman/
-- NonFatMan: home1.gte.net/res0658s/electronics/
-- When the going gets tough, the tough use the command line.