TriXarp - 196 voice FPGA polysynth

[JovianPyx]

I've just gotten proper sound out of a new FPGA synth design. It's a triple 64 string harp system called "TriXarp" (pronounce that 'try-harp')

The three 64 string harps can be addressed separately and can be detuned from each other. The harps are based on a set of Karplus-Strong string models.

Each note plucked activates all 3 harps, much like how a piano hammer hits 3 strings.

Stereo was acheived by using the string number as a panning parameter.

The sample is of me making keyboard mistakes while playing the synth with varying amounts of detune from very small to somewhat large.

The reflection filters can also be individually controlled, but for the sample, they are all set to a harp-like sound (which tends to sound bell-like at the high end).

I literally took the Xarp-61 design and instantiated it 3 times in this project. Xarp-61 is a 64 string harp model.

The FPGA I used is a Xilinx Spartan-3A DSP 1800. The synth is not quite finished, there's a lot of RAM left over so I will add a stereo delay effect.

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TriXarp_Sample_00.mp3
Description:	TriXarp samples
Filesize:	3.04 MB
Duration:	3:19
Viewed:	1781 Time(s)
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[emeb]

That sounds fantastic Scott! Amazing stuff.

[JLS]

Nice one THANKS great example

[Dan Lavin]

Scott: very nice! Even the very detuned samples at the end are useful.

[JovianPyx]

Thanks emeb, JLS and Dan Lavin.

The synth is now essentially finished (aside from whatever feature-creep I do from here forward). All three harps work, are in stereo with a functional looped delay effect.

I've been playing with tuning and it's amazing what can be done. I finally got some nice piano like beating by tuning one harp a bit sharp and another a bit flat. But instead of symmetrical tuning where the sharp harp is as sharp as the flat harp is flat, I made the flat harp half as flat as the sharp harp is sharp. (I hope that makes sense). This gives rise to a much more interesting beat pattern similar to when you press piano sustain and hit one note and then listen to it decay.

I am now working on a demo piece. I've chosen to use Robert Schumann's op. 15 no. 1, Von Fremden Laendern und Menschen. I have a MIDI file, but I don't like the expression nor the arrangement, but the notes are there so I can copy and paste to get the parts the way I want them and then the tedious task of editing the timing of individual notes to get the feel I want. When I finish that, I will post it here.

[JovianPyx]

Here is my first "willing to let people hear" version of Robert Schumann's op. 15 no. 1, Von Fremden Laendern und Menschen.

I will admit to starting with a MIDI file I downloaded, but there is precious little left of the original data. I may make some changes in the future, but for now, this is good enough to demonstrate the instrument. I chose to keep the detune effect very subtle, so the 3 strings for each note are slightly different. I used a small amount of delay effect with short delay time. It's just the TriXarp. At 1:23 it should be tolerable

EDIT ADD: I've updated the mp3. I had spelled Schumann with one n and this is a better recording.

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R.Schumann_Von_Fremden_Laendern_und_Menschen_op.15_no.1_.mp3
Description:	Robert Schumann's op. 15 no. 1, Von Fremden Laendern und Menschen played on a TriXarp synthesizer.
Filesize:	1.27 MB
Duration:	1:23
Viewed:	1762 Time(s)
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[JovianPyx]

And just for fun, here's a recording with TriXarp and my FM bell synth

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R.Schumann_Von_Fremden_Laendern_und_Menschen_op.15_no.1_trixarp_with_bells.mp3
Description:	Same piece, but with TriXarp and an FM bell synth (all FPGA)
Filesize:	1.29 MB
Duration:	1:24
Viewed:	1774 Time(s)
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