MN3005, MN3007 BBD.. anyone built one?

[Martin Czech]

> > I was puzzling over what the NE570N
> > compander was doing there. Is it normal 
> > to compress the signal before it
> > goes through the delay stage?
> 
> Compression at input followed by expansion at output is a noise
> reduction technique.  Here's my non-technical understanding of this
> process: Basically you compress the signal before it enters a device
> which introduces noise (like a delay line), then expand the signal after
> it leaves the device.  This (ideally) causes no change in the desired
> signal, but the noise which was introduced while the signal was
> compressed will become proportionally quieter to the desired signal
> after expansion.
> 

The infinite delay is not practical realizeable without a kind of
compression. You could dial the feddback only close to infinity, on one
side the signal would slowly fade, on the other it wold rise and rise,
until total distortion/and or oscillation. I think it needs a jard limiter
before the delay to get a real infinite delay without this problems.

m.c.