Re: Bose stereo question

[ti@amb.org (Ti Kan)]

MSV96@aol.com writes:
> << BTW, if you listen to a lot of tapes, the "DNR" function is neat. No, it's
> not "Dolby Noise Reduction", it's "Dynamic Noise Reduction." >>
> 
> DNR was created in the mid-80's as an alternative to Dolby B. (Cost reduction
> by basically avoiding paying Dolby for the lisence to use thier system.) DNR
> is a compander in a chip. I forgot offhand who invented it (National?).

DNR (also known as DNL for "dynamic noise limiter") existed well before
the mid 80s.  I had a Philips cassette deck in the 70s that had it.
It's basically a dynamic low-pass filter that varies its degree of high
frequency attenuation based on the signal amplitude.  You are probably
confusing DNR with "dbx" which is a true compander (compression/expansion
of the amplitude) device.

-Ti
96 A4 2.8 quattro
84 5000S 2.1 turbo
80 4000 2.0
-- 
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