designing a simple and original syth / noise box ?

low_rider · Joined: Dec 14, 2011 Posts: 14 Location: Israel

hello all... I come from a background in building guitar effects (and doing extensive work with microcontrollers for a big medical company)... I found myself getting more and more into electronic music and as I am somewhat fed up with designing guitar effects I would like to approach design of electronics instruments. Naturally I would like as much as possible with MCUs since that's something I know how to do.

I was looking into building a simple synth that might include a few sources, filters and a simple sequencer all in one small package. the thing is that it won't be compatible with other gear. what is common in that sense? also where can I find info regarding various synth arcituctures?

thanks!

synthesist · Posted: Thu Dec 15, 2011 12:24 pm Post subject:

comrade_zero · Posted: Thu Dec 15, 2011 9:53 pm Post subject:

Welcome to the realm of synth DIY. If you are looking to design a Microcontroller based synth there are a few designs you should check out:
Look for Paul Maddox, he's designed several, and authored a great article on programming MIDI with AVR's...
Elby designs has schematics for the MONOWAVE synth as well as the AVR synth...
The general architecture seems to be wavetable based digital oscillators from the MCU into an analog filter. (Check out the PICsynth for a really simple implementation.)
If you are going the MCU route
you should definitely include MIDI implementation. It is well documented and pretty straightforward. If your MCU supports serial communication you can build a MIDI interface with about 5 components (5 pin DIN connector, optoisolator, 2 resistors...)
If you want to build your own sequencer you may want to check out the MIDIbox site...
Anyway, hope some of this information helps, and welcome to EM!
Cheers,
c_z

low_rider · Joined: Dec 14, 2011 Posts: 14 Location: Israel

Thanks for the all the links and comments, I have what do read and learn for the next few days!

One thing that I've noticed early on is the 1V/Octave standard. This means that a sequencer should be able to output signals with an accuracy of 1/12V which sounds not very easy to get, maybe using a 16bit DAC that can run 7Vppk (for 7 octaves) or maybe more octaves are possible using a DAC with lower output range + 0 offset 0 drift Opamps?

Dougster · Joined: Sep 20, 2005 Posts: 272 Location: Tucson, AZ, USA

What MCU are you used to working with?

There are lots of places for information on the internet. I agree with comrade_zero that you should check out the MIDIbox site. The main portal is http://www.midibox.org and the details of the projects are at http://www.ucapps.de Check out the various AOUT (analog out) MIDIbox modules for ways to output control voltages for synth use.

http://www.electricdruid.net has a couple fun MCU projects.

To really learn about synths, I'd suggest getting at least some of the Electronotes collection. And there is still a lot of good information in the book Muiscal Applications of Microprocessors...