[sdiy] A crazy idea..

[Richard Wentk]

At 23:06 04/10/2005, Michael Zacherl wrote:
>Jeff Farr wrote:
>
>>Now, perhaps I'm way off base here, but I
>>believe it would be possible to patch together a modular so that both the 
>>audio and control signals are routed through the computer such that 
>>complete performances can be recorded.  Obviously the audio will work, 
>>but I can only speculate about controll signals being properly 
>>recorded...  Any thoughts?
>
>Ususally the A/D-D/A converters used simply don't deal with DC or very low 
>frequency signals. That's within their design. This chips are designed for 
>audio performance. It's a bit like making a pig fly.

If there are no blocking caps you can trim out any fixed offsets, there 
shouldn't be any reason why digitising control voltages shouldn't work.

I don't think A/Ds have built-in blocking caps. Last time I looked, which 
was a while ago, they didn't, but this may have changed.

D/A chips certainly don't. Full DAC circuits may do, but I've built a laser 
controller that handled down to DC without any problems. (Okay, with lots 
of problems, but DC output wasn't one of them. :-) )

Richard