User manual RANE THX 44

[. . . ] Install the supplied security cover after completing all settings. Be sure the POWER light fits snugly into the hole in the security cover. Never connect anything except an approved Rane power supply to the red modular jack on the rear of the unit. This is an AC input and requires special attention if you do not have a power supply exactly like the one originally packed with your unit. [. . . ] Wired per the Home THX Interconnection Standard. Refer to the silkscreened legend on the rear for pin identification. Use only THX approved DB-25 Interconnection cables. Other DB-25 cables may not function properly. CHASSIS GROUNDING If your system exhibits excessive hum or buzzing, there is an incompatibility in the grounding configuration between units somewhere. Your mission, should you accept it, is to discover how your particular system wants to be grounded. Try combinations of lifting grounds on units that are supplied with ground lift switches or links. If your equipment is in a rack, verify that all chassis are tied to a good earth ground, either through the line cord grounding pin or the rack screws to another grounded chassis. Units with outboard power supplies do not ground the chassis through the line cord. Make sure that these units are grounded either to another chassis which is earth grounded, or directly to the grounding screw on an AC outlet cover by means of a wire connected to a screw on the chassis with a star washer to guarantee proper contact. Sometimes cable TV systems can introduce another ground loop in combination with grounded amplifiers. Using an isolation transformer between grounded audio components may solve the problem. See Rane models BB 44x or BB 22. Manual-3 THX 44 CONNECTION Refer to the Home THX Audio System Block Diagram in the THX 44 Data Sheet for proper location of the THX 44. When first connecting the THX 44 to other components, leave the power supply for last. This gives you a chance to correct mistakes before damaging fragile speakers, ears and nerves. INPUTS Inputs are actively unbalanced and fitted with parallel RCA phono pin jacks and DB-25 connectors. Attempts to use both results in severe distortion. OUTPUTS The Outputs mimic the Inputs with one big exception: you may use both if desired. Use cables meeting the Home THX Interconnection Specifications available from Lucasfilm. SIGNAL LEVELS The THX 44 is designed for Home THX Audio reference levels of 0dBr (150mV rms), and provides a minimum headroom of 34. 5 dB above reference, making it virtually unclippable. With all LEVEL controls located in their 0 dB detented positions, the THX 44 operates with unity gain from Input to Output. No additional gain settings are necessary. Use the THX 44 only for specific equalization. [. . . ] Use only the recommended test equipment. It is not possible to align a Home THX Audio system without the use of proper procedures and a one-third octave realtime analyzer with averaging, and the special THX "Wow" Laserdisc (only supplied with some THX controllers or a licensed THX installer). The purpose of the THX 44 in a home cinema system is to flatten the response between speakers and the room. There are no special curves to follow; these are within the controller-- not the THX 44. [. . . ]