If there are others actually interested in this other than me....

download a spectrum analyzer here:

http://www.brownbear.de/

it works off your computer's soundcard and is free for a trial.

What I found was that the A-137 can emphasize the odd harmonics or the
even harmonics. By just listening you will hear a full sound when even
harmonics are emphasized, and a "pinched" sound when the odd harmonics
are emphasized... this was clearly seen with the spectrum analyzer.

the spectrum analyzer program is very helpful to visualize what's
going on here, and some high frequency harmonics are especially
prominent with certain symmetry settings.. with a fundamental at
1000Hz for convenience, I could get a very loud harmonic that was
almost in ultrasound range at certain settings.

fun.

--- In Doepfer_a100@yahoogroups.com , Florian Anwander
<Florian.Anwander@...> wrote:

>
> Hi
>
> > If I had a spectrum analyzer I'd figure my question out on my own..
> > maybe I can find a spectrum analyzer online
> If you have an oszilloscope which can take an external voltage for
> horitzontal control, you can use the A-100 to behave as an poormans
> spectrumanalyser:
>
> Feed the signal to analyse through a vcf in bandpass mode and put it to
> scope channel a.
>
> Take a LFO with saw (ramp) as wave form and feed it to a multiple.
>
> One connection from the multiple feeds the control voltage input of the
> cutoff frequencyof the filter over the complete audiorange.
>
> The other connection from the multiple is used as horizontal control of
> the scope.
>
> Done.
>
> Florian
>