[sdiy] Serge and multiples

[Colin Fraser]

> -----Original Message-----
> From: owner-synth-diy at node12b53.a2000.nl
> [mailto:owner-synth-diy at node12b53.a2000.nl]On Behalf Of
> Sebastian Kuehnl
> Sent: 26 February 2001 23:02
> To: synth-diy at node12b53.a2000.nl
> Subject: Re: [sdiy] Serge and multiples
>
> I got this from a non-listmember in reply to forwarding him
> the initial
> statement about internally normalling bananas. I want to post
> it here and hope
> I'm not offending him by doing so. Here goes
>
> "Having to put an internal comparator at every point you want
> to internally
> normal is significantly more complicated than a simple
> switching jack which
> requires no additional circuitry.  I addition, you may run
> into situations
> where the comparator would switch to the internally normalled
> patch even
> when something _was_ connected externally (for example, a
> bipolar LFO with a
> very slow sweep passes momentarily through zero, which the
> comparator would
> sense as "nothing connected" and switch briefly to the
> internally wired
> patch, causing a glitch in the sound). [...]"

Well yes, electronic switching is more involved than using switching jacks,
I wasn't really suggesting it as a practical solution, but if you gotta use
bananas...

In the typical case where all your module outputs are driven by op-amps your
bipolar LFO isn't going to get closer than a volt or so from the power
rails, so the unexpected switching problem would not appear.

Still, if modern op-amps are protected from continuous shorting to the
output of another op-amp (which I'd want to test), then Tony Clark's 100k
resistor to the +ve input for a normalled connection would be a more elegant
solution - and certainly cheaper even than switching sockets.

But I'm still going to go 1/4"

Colin f