As I mentioned in another thread, I'm looking for that now-classic
"Dolby A" sound. The easiest way seems to be to get an actual Dolby
encoder box.

I did some Googling, and here's what I found:

- The effect was usually done with a Dolby 301, and you simply removed
the bass expander card so you only affected (and effected) the mids and
highs. But the 301's are huge and not frequently sold on ebay.

- According to Bruce Breckenfeld, you can modify the "A" card used by
the Dolby 361; you clip R109 and R209, and this disables the bass
expansion. (http://www.ears-chicago.org/eardrum/2000.08.shtml) I
assume he's talking about the cat-22 card.

- The Dolby 363 is a two-channel version of the 361, but it uses
different cards, and I wouldn't know what resistors to clip.

Questions:

- I've also seen Dolby 360s around. How do they differ from the 361?

- All the recent 361s for sale had some sort of built-in Dolby A instead
of a cat-22 card, with what looks to be a blank plate where the card
would go. So I probably couldn't easily perform the modification.
Anyone know anything about these units, what the card is that comes with
them? Or am I misunderstanding the cat-22 card? Photos I've seen on
ebay show a level knob, etc. on the card. For example:


- Does anyone have a schematic for the cat-22 card? Maybe if I could
identify R109 and R209, I could find their equivalent on the SR/A cards
used by the 363 units, which are newer and easier to find.

--
Jay Levitt |
Wellesley, MA | Hi!
Faster: jay at jay dot eff-em | Where are we going?
http://www.jay.fm | Why am I in this handbasket?