Using an /|\ ST as a...

[Guido Goebertus]

Ingo wrote:

>An alternative would be the ROM port. There was a project of the German
>magazine c't that made a true parallel I/O port of the ROM port. I built
>that one back then, and used it as an interface for an EPROM burner.
>I could dig that article out (in German) if you're interested.

Yes! Very much. Exactly what I'm looking for!

>But perhaps it's possible to connect the DAC output to the inverting
>input of an opamp with a cap in the feedback path. This could be viewed
>as a "digital input" integrator. For an envelope generator, the output
>of the opamp integrator has also to go down sometimes, but this could be
>accomplished with another resistor from a negative reference voltage to
>the summing junction. And to keep the output at zero after the release
>phase has expired, a switch might be needed.
>
>Should be possible, but makes an envelope generator with linear slopes.

Yes.  Especially slow linear attacks don't sound very good.  

>For expo slopes I'd use Juergen's 4-tranny VCADSR core, and regular
>voltage output DACs.

I was thinking of using a current mirror between the DAC and the cap.
This way one can easily add another control voltage (to the mirror). 
But anyway, I was only playing mindgames with this whole DAC/ADSR
idea.  I try the MUX approach first...

Guido
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