Robert Orban wrote:

says...
Robert Orban wrote:
says...

Thanks Bob !

Him being the one who will be criticised on other groups for making DAB
and FM ever more distorted;!...

All modern DSP-based Optimods can be operated as exremely pure protection
limiters if that is what the broadcaster prefers, and we offer presets to
make this easy. I just make the artillery; I don't have any say in how
broadcasters choose to set it up!

BTW, did you ever use 'optical' compression ? Vactrols etc.

Only once, for a cue amplifier in a one-off broadcast console I built in
the late '60s for a friend's radio station. I drove the lamp from the output
of the cue power amplifier, which made the compressor very cost-effective.

Optical compressors are very interesting because of their complex, program-
dependent attack and release times. However, IMO they are not adequately
repeatable in a mass-production environment, so I never seriously considered
using them commercially.

One of my competitors did (in a four-band processor) and it caused him and
his customers no end of grief with unit-to-unit consistency problems and
temperature sensitivity.

I had them selected by Silonex and we had no such problems.
http://www1.silonex.com/

Their characteristics are indeed very interesting and seeming inherently suited
to music. My first use of them was in a mixer-amplifier to avoid accidental
serious overload. Tuning the time constants you could move the master fader from
'-5' where the amp was briefly clipping (largely inaudibly) to '+5' and you
could whizz the fader back and forth between the 2 points and the sound was
almost completely unaffected. It was as if you weren't doing anything ! It would
allow ~ 1% THD on tone and then cut-in.

More lately we used a Chinese device. Less consistent so required more selection
into grades and the fitting of grade dependent Rs on the control board. 1/8th
the price though.

Graham