[sdiy] Filters

[Magnus Danielson]

From: harrybissell <harrybissell at prodigy.net>
Subject: Re: [sdiy] Filters
Date: Fri, 02 Jan 2004 19:59:52 -0500
Message-ID: <3FF61407.A13D6FFD at prodigy.net>

> OTA might be more 'high tech' but also a lot harder to control. There is time
> delay through the OTA (not much but in a feedback loop it could be enough
> to notice)...

There is always a time-delay... but I think you really mean to say that there
is a phase-shift due to poles and zeroes in the OTA responce. Those details
naturally affect the feedback loop responce... unless you handle them. Also,
this varies between different implementations. If you're using something like
a 1486 you're in a different ballgame (look at the bandwidth specs of that
thing!).

> OTA has limited signal handling capacity, high offset voltage
> etc...

This is indeed true.

Have anyone considered the dBx VCA core? It seems to have a capability of a
high dynamic range (I've heard numbers like 130 dB of dynamics mentioned) and
would like a discussion on that in relation to OTA based things.

Cheers,
Magnus