[sdiy] Adding audio channels, to increase S/N

[john mahoney]

phillip m gallo:
> When decreased recorder generated noise was the goal, over-biasing,
> pre-emphasis, Keepex, Dolby A, and later dBX where the  games we would
play.

Companding, for the most part. Who was asking about cheap DACs? I remember
when 8-bit companding DACs were the slick new parts. Linn used them in the
LM-1. Perhaps they are still used for phones and voice recorders. Produced
almost the signal to noise ratio of a 12-bit linear, if I recall.


Magnus:
> I agree. All the math-waving of hands is partly lost in the not-so-linear
life
> of a magnetic tape... it only works quite that well in a real linear
systems.

Ethan:
> I'd add that these sorts of schemes depend heavily on the assumption that
> the noise in each channel is uncorrelated. ...

So, correlated noise such as hum will be amplified (and phased and all
that)?

--
john