[LAD] Plugin 1/oct frequency controls (AMS/MCP/VCO)

Fons Adriaensen fons at linuxaudio.org
Thu Aug 23 16:35:26 UTC 2012

On Thu, Aug 23, 2012 at 12:06:06PM -0400, David Robillard wrote:

> Well, it's not the end of the world, but it's certainly not very user
> friendly.  In practice, most users are just going to connect one
> "frequency" port to the other "frequency" port and expect the right
> thing to happen (and likely not even understand that -0.75 is the magic
> tuning number to make things in tune).

You will probably disagree (so let's agree to disagree :-), but the
user of a CV based synth, the real analog thing or an emulation,
can be expected to know this. And if not, it's rather obvious what
he's supposed to do, once he knows the function of the 'Tune' slider.

> 1) The sink has port with designation 'frequency' port and unit Hz
> 2) Does the source have a port with designation 'frequency'?
> 2A) If yes, and the units match, great, connect them directly
> 2B) If yes but the units don't match, connect them via a converter, if
> one is available
> 2C) Otherwise, and we don't have any specific knowledge about what to do
> with 'frequency', just leave it at its current value

That sort of thing can be very useful, but it's not what a user of
a CV based synth would expect. It's rather what he wouldn't expect.
On the real thing, you can connect any source to any destination,
TRS sockets are as dumb as they come, and the *only* thing the
manufacturer would take care of if that no connection would ever
damage the electronics. This is just part of the fun.

Even more: on the classic EMS synths which had a pin matrix instead
of patch cables, the CV mixing was purely passive. So adding a source
to a CV summing bus would actually modify the gain of the existing
connections, and you didn't even a have a fixed voltage/octave value.



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