The Dolby Cat. No. 222SR/A Module provides two channels of Dolby A-type noise reduction and Dolby SR processing. 

Install into Dolby CP-500 / CP500, CP45, CP55, CP65.

The Cat. No. 222SR/A card makes it possible to economically upgrade Dolby CP65

and CP55 cinema processors for decoding Dolby Stereo SR optical soundtracks. By

plugging into the slot usually occupied by the original A-type-only Cat. No. 222, it

eliminates the need for the two Cat. No. 350 cards previously required for SR

playback by the CP65, or the SRA5 adapter previously required by the CP55.

The Cat. No. 222SR/A provides all the functions of the regular Cat. No. 222 (A-type

NR, metering and switching) plus two channels of decoding for SR optical

soundtracks. Because it has been designed specifically for this purpose as opposed to

recording and post production applications, the Cat. No. 222SR/A is able to use

simplified circuitry and space-saving, custom-designed surface mount ICs.

Nevertheless, it incorporates all the fundamental SR techniques of its studio

counterparts, including action substitution, anti-saturation, modulation control and

spectral skewing.

The Cat. No. 222SR/A card will correctly decode both A-type and SR optical

soundtracks without compromise, however for special applications, the use of Cat.

No. 350s for SR decoding has a performance advantage in terms of headroom. This

extra headroom may be necessary in the case of playback of an SR magnetic print

master from a dubber. For instances such as this it is preferable to use the Cat. No.

350s even for a one-time screening. In the CP65 it is possible to have both the Cat.

No. 222SR/A and two Cat. No. 350s (or 300s) installed at the same time. To ensure

that the optimum choice is made when both types of cards are plugged in, logic

circuits on the backplane will automatically choose the Cat. No. 350s (or 300's) for SR

decoding. When the Cat. No. 350s are not present, the CP65 will default to the Cat.

No. 222SR/A

Certain backplane modifications may be necessary in order to properly utilize this new

card. The current revision (rev 3) of the CP65 backplane has been updated for the

card and includes the logic circuit. If your CP65 backplane is not the updated version

then some jumpers and a small board with the necessary circuit can be installed on the

backplane in order to provide the same functions as the newer backplane.

The CP55 does not allow the use of Cat. No. 350s. Jumpers on the backplane and

diode programming changes on the Cat. No. 243 card are necessary in order to use the

Cat. No. 222SR/A card.