[net.audio] Yet another Dolby question - Double Dolby

srm@packard.UUCP (SR Marcovici) (06/28/84)

I have a Technics RSM-273 (close to top of the line) Cassette deck
which has something called Double Dolby. I've been using it as if it
were Dolby B with no noticeable problems; the manual doesn't offer any
info on what the "Double" means. 

Any insight into this would be appreciated.

					Steve Marcovici
					AT&T Bell Laboratories
					packard!srm

pmr@drutx.UUCP (Rastocny) (06/28/84)

This Dolby scheme allows simultaneous record and playback monitoring.
Without the second Dolby circuit, the monitored playback would be
Dolby encoded and not sound like the original source material.

hrs@houxb.UUCP (H.SILBIGER) (06/28/84)

Double Dolby means that, on a tape deck with separate record
and playback heads, a separate cDolby processor is available
to decode Dolby on the playback head while the other
Dolby processor is being used to encode the recorded signal.
Some less expensive decks do not have this, and the
momitored signal therefore is not Dolby decoded. In the
playback mode the same Dolby processor is used as for
the recording. This of course is what always happens in
decks with a combinde record/play head.

The Dolby circuit can be B or C. If neither

is indicated, it generally is B.

Herman Silbiger CGE