Tube synth diy

On 3/19/07, kidkrazy58 put forth:
>   is that like a compressor maybe? Could some one explain to me how it
>could be used musicly. do any alterations to the cirucit need to be
>made? Thanks

While I've never heard the term "volume expander", an expander is
more or less the opposite of compressor -- it increases the dynamic
range of a signal.  They are primarily used for sound restoration and
noise reduction.

To which circuit are you referring??  Do you have a link??