[sdiy] RE: cross-fades (was ...)

[John Mahoney]

At 04:26 PM 1/15/2009, David G. Dixon wrote:
>This talk of VCFs has led me to another newbie question:
>
>What is the preferred method for implementing a cross-fade circuit?  I'm
>assuming one channel's gain is increased from 0 to 1 while another's is
>decreased from 1 to 0, and they both add up to one at any given setting?
>How exactly is this done (it doesn't involve dual-gang pots, does it?  That
>wouldn't be elegant at all!)?

Passive approach requires a ganged pot.

Active approach uses VCAs. One channel gets an inverted-and-offset 
form of the control voltage.

Vactrols may be another possibility.

John