[sdiy] Bach

Scott Gravenhorst music.maker at gte.net
Tue Apr 19 19:35:59 CEST 2011

Scott Nordlund <gsn10 at hotmail.com> wrote:
>> Thanks - I probably should have written what I used...
>> Xarp-56 - a 56 voice Karplus-Strong harp model. (struck or plucked)
>> PolyDrum - a 55 voice chromatically tuned tonal drum synth made of 55 state
>> variable bandpass filters which are "struck" (impulse excited).
>I've done similar- some small variations to this basic formula can produce a
>lot of simulated analog drum sounds. Though the actual analog circuits have a
>lot of nonlinearities that may be really difficult to analyze, really rough 
>approximations can sound surprisingly accurate. It's easily better than using

Hmm.  Thank you, I've been wanting to experiment with nonlinearities, but I've been unable
to determine myself nor find good information on where the nonlinearities are best placed.
 My guess would be the output of the integrators could be passed through a nonlinear
transfer function - my assumption is the some of the "grossest" distortion would come from
active components like OTAs.  In the PolyDrum, I've got quite some extra clocks per drum
that could be used for that.  It's good to know that it's better than using samples.

>> A 16 voice FM bell synth (8 oscillators per voice)
>This one seems to give it a particularly nice quality. I think FM benefits 
>a great deal from heavy layering (as used in the Synclavier).
>> 127 voices in all.
>I've got some recent stuff too that showcases self-developed stuff. I'm a bit
>hesitant to spam up the list or hijack your glory with it but I've gotten a
>good response so far.
>They feature neat additive/wavetable synthesis algorithms, waveguide stuff,
>a variety of resonator type things, emulated Roland VP-330 stuff (not that
>it's really audible in the final product), algorithmic composition, self
>developed reverb algorithms, some weird pitch follower stuff...

I'm curious about resonators, I found using an SVF was intuitive for me, whack the input
and it rings out at Fc - but are there other (digital) ways?  And are there other ways to
"whack" the input (I've wanted to try a noise burst instead of just an rectangular pulse)?

>And sonically it's probably the best and most polished sounding stuff I've
>done to date.

Thanks!  I'll check it out - not spam to me, I like knowing what others are doing with
their DIY instruments - for one thing, I get ideas that way.

-- ScottG
-- Scott Gravenhorst
-- FPGA MIDI Synthesizer Information: home1.gte.net/res0658s/FPGA_synth/
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-- When the going gets tough, the tough use the command line.

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