Harry Lavo writes:
wrote in message
news:U0X2b.273374$uu5.61876@sccrnsc04...

Dolby SR ain't identical to anything available in the early 70s.
People might like nice warm analog sound, but good old fashioned tape
hiss would rather spoil it.

Four-band professional Dolby A was in use from about 1968 on. I
used it myself from 1971-75 when doing location recording and still
have a pair hitched to my Ampex 440B. The SR was simply a lower
per channel cost, more convenient upgrade of that system, I
believe.

My understanding is that Dolby SR (1986) has significantly superior
dynamic range. I remember reading that Ray Dolby was very proud of
the system, and in interviews said he thought it was his greatest
achievement. So no, I don't believe Dolby SR was technology identical
to that used on those great early-70's pop albums, although I've never
used it myself.

Andrew.