Dolby Laboratories CP65 manual Section Initial SET-UP and Installation

2-1

SECTION 2

INITIAL SET-UP AND INSTALLATION

Before you remove or replace the Cat. No. 240A Optical Pre-Amp or the Cat. No. 249 Power Supply Card, first disconnect AC power from the CP65 to protect the speakers and the CP65 from damage. For all other modules in the CP65, first switch to BYPASS; you can then safely remove or replace the desired card without disconnecting power from the CP65.

Do NOT connect the CP65 to mains power until all connections have been made and all jumpers have been installed (see STEP 9 later in this section).

STEP 1 If air-conditioning noise is audible in the theatre, arrange for lubrication of the motor, fan bearings, adjustment of belts and drives, and cleaning of filters to reduce the ambient noise to a minimum.

If the CP65 replaces an existing cinema sound system, play a typical film before you remove the old system so you will have a benchmark for comparison to the new system and as a check of the positioning of the exciter lamp, the focusing of the sound track lens, and the condition of the solar cell.

Before you run the film:

•Verify that the existing power amplifiers are in good working order.

•Verify that the existing speakers are in good working order, and that there is no loose or missing hardware or structural members in the enclosures.

•Verify that all wiring is present and properly connected and that crossovers are operating and are correctly adjusted.

•Check the phasing of the speaker connections (see Appendix A).

•Verify that there are adequate earth (ground) connections.

•Verify that radio interference problems are adequately resolved.

STEP 2 While you are running the film, listen carefully in various parts of the theatre for audio system problems:

•Hum.

•Noise, clicks, pops.

•Distortion.

•Poor tonal balance (lack of high-frequency or bass content).

These problems must be resolved before you can proceed to the next step in the installation.

STEP 3 To avoid heat problems, do not locate the CP65 immediately above or below the power amplifiers.

Always leave a 1U (43 mm, 1.75") space above and below the CP65 to provide adequate ventilation. Install an air guide or baffle to deflect hot air from equipment below the CP65.