[sdiy] VC Mixer

[TIm Daugard]

After thinking about this off and on over the weekend, I can see some
interesting things in the concept. A VC mixer can have a remote control station.
It can be made patchable so that on control can simultaneously control four
channels, while another controls only one. It can use a lag generator to create
extremely long fade ins or fade outs. We can create anarchy. Give each person a
foot pedal and a line to the mixer and watch how fast the mix gets totaled.

Technically, it allows keeping audio out of slider pots. Filters on the slider
pots can keep all the pot noise off the signals. There are several commercial
VCAs becoming available or it can built with the cleanest design anyone can come
up with.

I have some slide pots I bought to make a mixer before I decided it would be too
much work. I'm going to take them and maybe one or two associated rotary pots
and create a voltage control panel that can be multi purpose. I will use a
regulator to feed the pots and opamps to buffer them.

It will take a ribbon cable (10 to 20 ft?) to get the voltages back to a rack.
Because of the distance, I think I will run a two wire current loop for each
output to keep the signal noise free. A current to voltage converter on the
other end of the cable brings us back to the voltage realm.

Another project to put on the bench, sigh. I did get a power supply, a shortwave
radio, and a VHF radio repaired this weekend. My son and I also fabricated an
aluminum panel for part of the dash of his sports car.

Tim Daugard

BTW thanks for the info on the ceramics caps. Now I'm going to have to do some
research to see if the ceramic cap distortion can be made musically useful. I'm
still trying to figure out how to simulate high voltage across carbon comp
resistor distortion.










----- Original Message -----
From: "Edu Silva" <bahi0387 at terra.com.br>
To: "Laurie Biddulph" <elby_designs at ozemail.com.au>; "Synth DIY"
<synth-diy at dropmix.xs4all.nl>
Sent: Monday, May 17, 2004 6:52 AM
Subject: Re: [sdiy] VC Mixer


> Laurie Biddulph wrote:
> >
> > Anyone familiar with the Klark Teknik DN3600 and able to identify the
> > KTR008 chip and the one used for IC1 - IC5 in the Equaliser section
>
>
>
> It's a custom-made discrete "IC", avaliable only through K-T.
>
> --
> abraços,
>
> Edu Silva
> ES2 Audio
> Salvador-BA