[. . . ] The MASTER INPUT LEVEL control on the front adjusts both Right and Left Input signal levels together. Never connect anthing except an RS 1 or other approved Rane AC power supply to the red thing that looks like a telephone jack on the rear of the SM 26B. [. . . ] MIX/PAN serves two different functions: MIX: When used as a SPLITTER, this controls the mix of Left and Right Master Input program to each Channel's MONO OUTPUT. PAN: When used as a MIXER, this control pans the Mono Channel Input between the LEFT and RIGHT MIX OUTPUTS. MASTER INPUT LEVEL sets the gain of the Left & Right Master Input stages, with a range of Off to +12 dB. In the splitting mode, this controls the Level of all Mono Channel Outputs at once (i. e. , those which do not have a separate input). Manual-2 REAR PANEL DESCRIPTION LEFT & RIGHT MASTER INPUTS are balanced Tip-Ring-Sleeve (TRS) ¼" Inputs. Connecting to individual MONO INs disconnects that channel from these Inputs (refer to the Block Diagram found on the SM 26B Data Sheet). For unbalanced operation use a standard mono ¼" plug; for balanced operation use a TRS (stereo) ¼" plug wired as follows: TIP is signal + (connect to Pin 2 on a 3-pin connector). LEFT & RIGHT EXPAND OUTPUTS: ¼" TRS jacks that are connected in parallel with the Master LEFT & RIGHT INPUT jacks, allowing two or more SM 26Bs to be daisychained for multiple splitting. Simply connect these EXPAND OUTPUTS to the LEFT & RIGHT INPUTs of another SM 26B; there is no limit to the number of expansions possible with the SM 26B. Therefore it is not possible to mix both balanced and unbalanced lines in the same channel between several units: once the ring and sleeve are shorted anywhere in the chain (by using a mono plug) the entire line becomes unbalanced. MONO INPUTS are TRS ¼" jacks which accept either balanced or unbalanced mono signals. These are switching jacks which automatically bypass the Master LEFT & RIGHT INPUTs whenever a plug is inserted (see the Block Diagram). MONO OUTPUTS: ¼" TRS jacks deliver either a conventional unbalanced output (use mono cords), or a balanced output (use TRS cords). [. . . ] 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. [. . . ]