[sdiy] Analog bandwidth

[cheater00 .]

On Sat, Feb 22, 2014 at 1:47 PM, Michael Zacherl
<sdiy-mz01 at blauwurf.info> wrote:
>
> On 22 Feb, 2014, at 1:33 PM, cheater00 . <cheater00 at gmail.com> wrote:
>
>> I believe adding shaped, ultrasonic noise before a VCA is a way to
>> shape transients during fast A/D/R stages. It should also work in a
>> compressor (you must not add the noise to the sidechain, though).
>
> I wonder if this also applies when using programming environments, like
> SuperCollider, Max/PSP, Puredata, Csound etc. In theory it should, given
> that the basic elements used are pure and 'un-shaped'.
>
> Michael.

Yes, but when doing multiplication or non-linearities or IMD in
digital the typical rules for oversampling apply. So you'd have to
take, say, a signal that goes up to say 100 kHz, and then oversample
it quite a bit.. that's computationally expensive. Why 100 kHz? For
example in multiplication you obviously get sum and difference
components. So depending on the frequency content of the envelope of
your VCA, you'll at most push the noise (which is at 20 kHz - 100 kHz)
down by that much. If you want a nice thump you'll make the envelope
push down the noise by those 20 kHz or more. As the envelope goes
faster, I imagine you would get typical "overdrive" type effects
happening on the noise.

Andy said he was going to check whether adding some ultrasonic noise
makes sense for fast attack settings in his Glue VST but I don't
recollect if we spoke about that afterwards.

Cheers,
D.