[sdiy] Simple VCA schematic, anyone?

[Andre Majorel]

On 2007-01-08 23:02 +0100, René Schmitz wrote:

> You have to run the emitter into a virtual GND of an opamp,
> possibly via a DC blocking cap.

Ah yes, one of 'em vertual grownds. Like this ?

   IN  o---
(-5~+5V)   |
           <                                         ----^v^v----
      9.9k >                                        |    100k    |
           <   _                        _           |    _       |
           | +  | -                   +  | -        |   | -_     |
           +---||---+-------       -----||---^v^v---+---|-  -_   |
           |   _|   |       \     ^     _|    1k        |TL071>--+---o  OUT
           <        <        \   /                    --|+ _-
       100 >  33µ   > 330    =====      1µ           |  |_-
           <        <          | BC550               |
           |        |          |                    _|_
          _|_       = 470p     |
                    |          |
     VC  o---^v^v---+----------
(0~15V)       1M

(Please realise that you are talking to someone who didn't who
what a virtual ground was until five minutes ago.)

-- 
André Majorel <URL:http://www.teaser.fr/~amajorel/>
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