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Author Topic: Notes on a couple of Dolby B Decoders - Teac AN-180 and Advent 100A  (Read 2179 times)

Offline stellavox

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A customer sent me a Teac AN-180 for "upgrading".  This activity allowed me to "update my understanding of" Dolby B decoders in general, this Teac, and an Advent 100A that I happened to have in my "to do" pile.

Most of these "stand alone" decoders were designed to "plug in" between your tape recorder and your system's preamplifier / control section and decode a pre-recorded tape that was encoded with Dolby B noise reduction.   

The "upgrades" consisted of replacing 3 or 4 coupling capacitors in the input stages of the decoding section and adding regulation to the power supplies.  The Teac  had a "first generation op amp" in the output section which I bypassed.  The output amplifier in the Advent was discrete so I left it in.

Listened to both finished units and slightly preferred the Advent.  Sent both to the customer, and he did also.  He may keep it - or it's "up for grabs".