MOTM

----- Original Message -----

From: Bob Colwell

To: MOTM

Sent: Sunday, February 06, 2005 4:04 PM

Subject: [motm] an all-digital "analog" synthesizer

I have an idea that's been kicking around in my head for the last 25 years: what's the best way to

combine the strengths of both digital and analog electronics to make a modular synthesizer.

Picture a modular analog synth. I believe the day is coming when I could replace the analog

guts of any of the modules with one DSP-like device, programmed to provide the function

of that module, be it filtering, envelope generation, VCO, etc. Powering up the machine

would cause each DSP to be programmed for its function by some master CPU. Want

another VCO? Just make one. Could also keep the programming in flash, possibly

incorporated directly on the DSP chip. Silicon capable of doing this is pretty much

available right now.

To capitalize on the strength of the digital part of this rig, I'm thinking the interfaces between

modules should be digital, not analog. But I'm somewhat torn on this part -- there's something

satisfying, logical, and concrete about connecting a patch cord from the output of one

module to the input of another. Even with digital protocols we could still have patch

cords.

But the digital world doesn't really need 'em. You could have a very general routing

interconnect network inside the box that allows anything to connect to anything else.

The question is how to control that routability and how to make it readily visible to

the machine's operator.

To really take advantage of the extreme programmability of the modules, you'd

probably want each of them to have some kind of display that reflects the current

function of that module. LCD displays are pretty expensive right now, especially

the color ones that I think would be necessary to quickly distinguish the various

modules.

Why would anyone want such a rig? Well, one major reason is that you could

get all of the "knobs" back to their exact settings later, something that I never

could achieve with an analog synth. In fact, if the patching is done via a routing

network, you could reconfigure the machine to precisely what it was at any

previous time. Maybe a combination of internal routing network plus patch cords?

Anyone else ever thought about doing this?

-BobC