linear portamento, minimoog style...

Harry Bissell harrybissell at
Sat Nov 27 03:11:23 CET 1999

I'll forward you a schematic for a "linear" portamento... sorry there is
no PCB for it. Its easy enough to wire by hand.
OTOH: the PAiA synths have a "linear" oscillator response... the mini
had an "expo" oscillator response.

So the PAiA:   Linear Oscillator + Linear Portamento  <or>
                       Linear Oscillator + Exponential Portamento

won't be quite like the
Minimoog:       Exponential Oscillator + Linear Portamento

IMHO I like the linear portamento the best anyway... If you want a
minimoog sound the PAiA might not quite get it.

I'll post the portamento monday... its a work and I don't want to draw
it over again...

Another easy way to get "portamento" is to put the KBD CV through a
hipass R-C filter (cap in series, resistor to ground) and then invert
the output and sum it with the KBD CV at the oscillator input. This is a
simple and nearly passive way to get glide... I did this on a PAiA 2720
before I "discovered" the glide circuit I'm posting (monday)

:^) Harry

Mark Cornell wrote:

> Hi,
> I'm planning my first DIY synth.
> After looking at the Fatman, I thouht it was a bit
> limited so looked at the 9700 series modules
> instead.
> I plan to build the Paia 9700 synth, as it comes,
> and then expnad it as my knowledge increases, but
> I really want to get that Rick Wakeman sound.
> One of the suggestions I had was to use linear
> portamento instead of exponetial.
> Any ideas? I'm thinking along the lines of something
> a thicko like me can understand, a ciruit and PCB
> that I can stick together and work out by assemble,
> instructions etc. It's how I learn best.
> Cheers.
> --
> Mark Cornell
> Ringwood School

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