[sdiy] New to the list

[Stefan Schneider]

>> My Synth background is a little funky...

>I like the word 'funky' it just doesnt get used enough :-)

It just got a bad rep during the 70's :D

>:-P
>OK, fine way to start, make us all jelous!

Honest to god, most (well actually ALL) of you make me jealous... since I
was young I wanted a modular and seeing some of the DIY projects made me
want one even more :]

>Ive heard good things and bad things about this midi to CV unit...

Can you spare some lines on the pros and cons? I've been reading the source
code, seems pretty "innocuous" :] and probably enough for my needs. I have
to admit that the external memory might be overkill for some smaller
projects, fortunately I have a bunch of EEPROMS lying around

>take a look at the one Tony Allgood sells (MidiDAC), its popular and works
>reliably...

I will, I like the PIC better than the i8051

>> My second question is about my pot to MIDI implementation...

>Ok, you're going to have problems with the DACs...
>Look at the schematics, some of the pots arent voltage sources, they are
>resistances (resonance pot is the first one to spring to mind), so you'd
>need to convert the filter to be FULLY voltage controlled...

I've been thinking about replacing most of the pots with voltage controlled
resistors, another option would be cascading three opamps to make a voltage
to impedance converter but the problem with that approach is the insanely
large amounts of parasitic capacitance I'll get.

>Also take a close look at the EGs , I bet they've used resistance rather
>than voltages for some of the parameters.

Will do! In most cases reading the value of a resistance is not a problem.
As Harry pointed out, Vactrols could be another option, and my intention is
to capture the important parameters (First of all, the oscilator and LFO
settings). I might end up doing the oscilators and ADSR EG using wavetable
synthesis instead of pure analog, and then only capture the filter and LFO
analog values (They HAVE to be analog :)

>What you're planning to do is a MASSIVE task...

My wife's already planned most of next year without me :] (In a good way)

>Im sure people here will be able to help though..

I truly appreciate that!

Cheers

Stefan