[sdiy] Simple compressor, agc, ?

[Toby Paddock]

Howdy,
I'd like to build a very simple AGC type thing 
for a "tuning display". Room mic (or whatever 
tuning standard) gets compressed like 100% and 
drives the horizontal of an o-scope. Whatever 
you're playing gets compressed some and drives 
the vertical. Then look for lissigu... 
lissajue... lissijou...   some of those patterns.

Need:
Pretty high compression. 
Cheap and easy.
A few volts output. Either +/- or 0-V.

Don't care too much about:
Distortion, noise, speed, freq response.

Thanks,
Toby Paddock