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Cross-fading: UAP vs ACPR [Was Re: My first (and last) custom pan

2007-05-30 by paradigmshiftbeats

--- In SergeModular@yahoogroups.com, "riluttante" <riluttante@...>
wrote:
> So you're saying they both have a slight lag to them, an audible
> "fade" between the two input signals no matter how steep the slope
> of the CV is?

I think what you're experiencing in the UAP is its equal-power
curve, not a lag on the voltage per se. I frequently use my ACPR
with audio and don't have any complaints. You lose a built-in VCA,
but if you simply want to fade waveforms/filter outputs, vary the
depth/source of feedback loops, etc, then it works quite well. I
know I've done "hard switching" between two ACPR inputs using the
Sequencer in the past. I'll try again tonight using a DSG if I can
find the time and report back.

What CV sources have you been using to attempt this with your UAP;
perhaps the waveform you're putting in is not completely square?

Also, as I said initially the equal-power curve may be affecting
your ear's perception of the fade of two audio signals. I had a
conversation with Rex once in which I commented that I generally
prefer the "linear" fade of the ACPR to the UAP. In the wonderful
manner that Rex does, he spent the next five minutes explaining in
detail why the ACPR fade is in fact NOT linear. My recollection is
that the layman's version of Serge fading is something like this:

linear fade = x
ACPR = x^2
UAP = x^3

Maybe someone with actual technical expertise can better elaborate.
In any case, you may find the effect you're seeking is more easily
achieved using the ACPR's "x-squared" approach.

Hope this helps!
Chris

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