VC Panning querie...

[Happy Harry]

The big problem is to get the "image" to move
between the two channels in what the ear hears
as a linear fashion.

There is an EFM circuit VCA6b (i think) that gets
this effect. Don't know about the linearity though...

I'm using it to cross fade two tone circuits.

Check out how its done... (www.xavax.com/efm)

The 3080 CONTROL pin looks like two diode drops
away from the negative rail. You must source a
current into it (resistor to a more positive
voltage... like ground or V+) Most schemes use
ground and a PNP transistor, this may be where
you got the "Ground and V-" idea from.

At the normal inputs its just like a normal
op-amp. But the differential voltage must be kept
quite low... maybe .3V or less. This is why there
are usually big resistive dividers at these points.

Check out "OTA Tutorial" by Gene Zumchak at
Rene Schmitz's site (and one other I forget...)

This will explain the 3080 / 13600 / 13700 real
well.

H^) harry

>From: Ken MacBeth <macbeth2600 at yahoo.co.uk>
>To: synth-diy at node12b53.a2000.nl
>Subject: VC Panning querie...
>Date: Mon, 15 Jan 2001 21:31:24 +0000 (GMT)
>
>Anyone know of any Voltage Controlled Panning
>circuits/schematics out there? I've, personally found
>this a hard thing to implement. I have an idea to use
>a pair of voltage controlled companders contained
>within a single NE571. Looking at the specs for this
>thing (571) it would apprear to be voltage
>controllable. The other option is to use two 3080s one
>recieving an inverted control, but, alas here is where
>I screw up! My understanding of 3080/13700 is that
>they only work from OV down to the negative rail. I
>know that this must be wrong! Any help out there?!!!!
>
>
>____________________________________________________________
>Do You Yahoo!?
>Get your free @yahoo.co.uk address at http://mail.yahoo.co.uk
>or your free @yahoo.ie address at http://mail.yahoo.ie

_________________________________________________________________
Get your FREE download of MSN Explorer at http://explorer.msn.com