User manual RANE FDA 28

[. . . ] If 1 x 4 STEREO operation is chosen, all switches should be in the opposite position. Mix settings as each application demands. NEVER CONNECT ANYTHING EXCEPT AN APPROVED RANE POWER SUPPLY TO THE RED THING THAT LOOKS LIKE A TELEPHONE JACK ON THE REAR OF THE FDA 28. This is an AC input and requires special attention if you do not have a power supply EXACTLY like the one that was originally packed with your unit. [. . . ] Monoing one Output pair will have no effect on the other Outputs. Each pair of OUTPUT controls sets the individual Channel Output levels. The inner knob is for Channel A (or odd), the outer is Channel B (or even). When this yellow LED is illuminated, the foregoing information should be correct. If darkness is present at this location, most or all of the above will be inoperative. REAR PANEL DESCRIPTION The FDA 28 uses Euroblocks that disconnect and accommodate any wire size from 26AWG to 12AWG. Use these for either Microphone or Line level INPUTs to be distributed by the FDA 28. Connect balanced sources to the respective "+"and "­" terminals, and choose a shield grounding terminal (either signal ground (SIG GND) or chassis ground). Unbalanced Inputs should connect to "+" and SIG GND only. When using an unbalanced Input you may leave "­" open, or short it to GND. In the out position, the respective Input stage is set for Microphone Input levels. In the depressed position, Line level signals are accepted. In the on position, 15VDC PHANTOM POWER appears present on each INPUT, and the LED lights. Connect two conductor shielded cable to "+"and "­" terminals. Tie the shield to chassis, signal ground, or leave open--your choice. For unbalanced use, you must tie the "­" to SIG GND. Failure to do so results in improper operation. This switch provides the ability to separate chassis ground and signal ground. Normally, this switch should be in the LIFT position. In some circumstances it may be necessary to move it to the opposite position to eliminate stubborn hum and buzz problems. See the CHASSIS GROUNDING note on the last page for details. If you are tempted to try moving this switch with your power amplifiers turned on or turned up, don't be. Always turn your amplifier levels down before changing your grounds around and then bring them up slowly. [. . . ] The unit is shipped with this switch in the "grounded" position, tying circuit ground to chassis ground. If after hooking up your system it 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. [. . . ]