[net.analog] Is there a simple Dolby Circuit

ld (03/22/83)

I have several questions.  1) Is there a commonly available Dolby
noise reduction integrated circuit (I noticed that it appears
to be a chip in my Teac cassette deck)?  2)  Can anyone provide
a pointer to the specifications for Dolby A/B/C (I will design
the circuit if I can find the specs)?  3)  Can anyone provide
a pointer to a working Dolby circuit (ala Electronics,
Electronics Design, Popular Electronics (I am not proud) ... etc.)?

I realize there are patent rights on equipment using Dolby, but
surely someone at Southwest Technical Products designed a general
purpose Dolby and published it in Popular Electronics at some
time (at least, they used to publish their favorite circuits,
along with their address to get the PC board, when I used to
read that magazine).

If no one has any pointers for Dolby, how about DBX or any
other noise reduction unit for mag tape.

I have been out of hardware and into software for too many
years and my collection of electronic journals has slipped
far out of date.

Please reply by mail.

		Thanks,
		Larry Dwyer
		ucbvax!hpda!ld