LPC MicrocontrollersのトピックRe: The dsp-G1 analog modeling synthesizer

The dsp-G1 analog modeling synthesizer

lpcware — Wed, 15 Jun 2016 19:59:55 GMT

Content originally posted in LPCWare by janost on Fri Jun 13 14:52:43 MST 2014
I took the LPC-810 and wrote a MIDI based dsp synthesizer on it.

44.1KHz/16-bit PCM audio with a sigma-delta DAC.
15 DCO analog modeling synth with 24db resonant lowpass filter.

It doesn't use a wavetable.
All waveforms are algorithmically calculated.

It's at http://igg.me/at/dsp-G1.

Re: The dsp-G1 analog modeling synthesizer

lpcware — Wed, 15 Jun 2016 19:59:56 GMT

Content originally posted in LPCWare by janost on Fri Jun 13 14:54:03 MST 2014
http://www.youtube.com/watch?v=w-IUmPD-LuI

http://www.youtube.com/watch?v=dLucvhlYfVU

Re: The dsp-G1 analog modeling synthesizer

lpcware — Wed, 15 Jun 2016 19:59:57 GMT

Content originally posted in LPCWare by janost on Fri Jun 13 14:55:40 MST 2014
Yes, I tried it on the ATmega and it works but there isn't enough horsepower to make it hifi. ;-)

No, It doesn't use wavetables. All waveforms are algorithmic.

Yes, it uses a sigma-delta DAC, 16-bits/44.1KHz on a digital pin and not PWM.

No, it doesn't have analog inputs so the boxed synth uses an Arduino Pro Micro to scan the knobs.

Yes, without the knobs the whole synth fits inside the MIDI-plug and uses phantom power :)

Re: The dsp-G1 analog modeling synthesizer

lpcware — Wed, 15 Jun 2016 19:59:57 GMT

Content originally posted in LPCWare by janost on Sun Jun 15 04:47:02 MST 2014
Got it featured at Hackaday.

http://hackaday.com/2014/06/14/an-arm-based-dsp-modelling-synth/

Re: The dsp-G1 analog modeling synthesizer

lpcware — Wed, 15 Jun 2016 19:59:58 GMT

Content originally posted in LPCWare by starblue on Mon Jun 16 04:49:22 MST 2014
Can you explain the sigma-delta modulation a bit more?

I don't see how you can get 16 bit at 44.1 kHz with a first-order sigma delta DAC, and I don't understand whether you can do 2nd order with just a capacitor as the analog part.

I've seen this page, seems to be some older version:

http://www.hackster.io/janost/micro-virtual-analog-synthesizer

Jürgen

Re: The dsp-G1 analog modeling synthesizer

lpcware — Wed, 15 Jun 2016 19:59:59 GMT

Content originally posted in LPCWare by janost on Mon Jun 16 05:53:47 MST 2014
The output in the schematic is a dirty one.
It actually needs a lowpass filter.

It took an awful lot of hours makeing 2 of the SCT's working as phaseaccumulators ;-)

Re: The dsp-G1 analog modeling synthesizer

lpcware — Wed, 15 Jun 2016 19:59:59 GMT

Content originally posted in LPCWare by janost on Tue Jun 17 19:23:04 MST 2014
I don't want to say how I did it.

But I want to say that I ordered another 50 pcs of the LPC-812.

I just love it.

:)

Re: The dsp-G1 analog modeling synthesizer

lpcware — Wed, 15 Jun 2016 20:00:00 GMT

Content originally posted in LPCWare by janost on Sat Jun 28 07:28:31 MST 2014
Once I learned and mastered the SCT on the LPC-8xx, I can do some really awesome things.

But I don't feel like handing out how to others.