[sdiy] Thru-Zero, was as3340 PW/tuning issue

[Mattias Rickardsson]

Den sön 5 jan. 2020 03:37ColinMuirDorward <colindorward at gmail.com> skrev:

> Hi Adam,
> TZ fm is more like what you get in a digital FM synth.
> On a regular VCO, when the FM input goes to negative, what happens to the
> VCO frequency? I think it either stops, or simply bounces back to the
> positive domain. For this reason, you get some harsh harmonics (which can
> sound great).
>

No, you get a bent pitch, since the VCO stays at 0 Hz for a while instead
of going below zero.

A TZvco handles the incoming negative FM differently. It reverses the VCO's
> direction. Or, another way to think of it is that it flips the phase of the
> VCO.
>

No, it reverses its direction. :-)

This gives that nice Chowning style FM that we know and love.
> Someone else might chime in with a more accurate explanation... I could
> have butchered it.
> Just waiting for alfa rpar to produce an economical TZvco chip, then we
> can all get familiar and know it by ear.
> Colin
>

It could be someone else than Alfa as well.

Den sön 5 jan. 2020 04:06Jason Proctor <jason at redfish.net> skrev:

* -11 :-)


Hahahaha, very funny! :-D

/mr
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