SV: [sdiy] Digital VCO web page available

[Eric Brombaugh]

Karl Ekdahl wrote:
> That's pretty awesome i have to say, $2 oscillators!
> Will there be any temperature drift or other "analog
> inconcistencies" due to the cv-summer? I guess it
> should be really easy to set up a cheap polyphonic
> system with these..
>   
Yup - the PSoC chips are about $3.00 in single quantities and drop to 
less than $2.00 for when you order more than 25 from Digi-Key. The 
op-amps & discretes add a few more cents. You could definitely populate 
a board with a handful of these and create all kinds of interesting sounds.

I've got no feel for how much temperature drift you'd get from typical 
1/4W carbon resistors. However, I imagine that the 2.5% accuracy of the 
PSoC main oscillator would be more of an issue. If absolute accuracy is 
required, then the DVCO could be easily redesigned for much greater 
stability by using an external crystal reference and tighter tolerance 
external components.

Eric