Rane FMM 42 - Manual (Page 3)

REAR PANEL DESCRIPTION
1. 3-PIN INPUT CONNECTOR. To be used for either mic or line inputs, pin 2 is hot
“+”, pin 3 is return “–”, and pin 1 is signal ground. Unbalanced inputs should drive pin 2
and use pin 1 as ground.
2. MIC / LINE SELECTOR. In its out position, this switch sets the input stage gain
for microphone usage. When pushed in, the gains are restructured for use with line level
inputs.
3. STEREO LINE 2 INPUT. This is a TRS stereo input. Tip is connected to Channel
A, ring gets connected to Channel B.
4. FLEX BUS INPUT CONNECTOR. When using the FMM 42 with other Flex
mixer modules, the Bus Output of the last module in the system prior to the FMM 42
would be connected to this Input via the 7-pin DIN cable (supplied).
5. FLEX BUS THRU CONNECTOR. To be used in situations where more than one
master module is required. When two or more FMM 42s are required, the second
modules’s Bus Input should be connected to this Output.
NOTE: Special cabling may be constructed which would allow the
bus inputs and outputs to be used for direct inputs and outputs.
See the Flex User’s Guide for additional information.
6. AUX A AND B BUS OUTS/LOOPS CONNECTORS. These ¼" TRS (tip=send,
ring=return) connectors may be used for inserting reverb units or other signal processing
devices (e.g., FPE 13s and FME 15s) in series with the Aux A and B Bus Return Loops.
With Flex units, use a single ¼" TRS cable connecting these inserts to the Patch I/O jacks.
Note: these Loops may be used as additional line inputs when the Flex Bus Inputs are not
used. This requires special ¼" TRS cables with Tip left open, Ring as signal hot and
Sleeve as ground. Additionally, they may serve as AUX outs by using a mono (tip, sleeve)
connector.
7. MASTER A AND B OUTPUTS. These 3-pin balanced outputs use pin 2 as hot,
pin 3 as return and pin 1 as signal ground. For unbalanced operation, pin 2 should be used
as hot and pin 1 as ground. Do not short pin 3 to any other pin. Leave it open.
8. POWER INPUT CONNECTOR. USE ONLY A MODEL RS 1, RAP 10, FRS 8,
OR OTHER REMOTE AC POWER SUPPLY APPROVED BY RANE. The FMM 42 is
supplied with a remote power supply suitable for connection to this input jack. Consult
the factory for replacement or substitution.
9. CHASSIS GROUND POINT. A 6-32 threaded hole used for chassis
grounding purposes. See the CHASSIS GROUNDING note on the last page for
details.
10. GROUND LIFT SWITCH. On this unit, the Ground Lift switch is
located along the bottom edge (vertical mounting), or along the right-hand side
(horizontal mounting). Since the switch’s location may prevent easy use once
installed in the rack, it is suggested you decide which position is required, and
set it before installation. The LIFT position is when the switch is slid to the rear
of the unit.
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. We realize a scientific explanation of this switch would be helpful, unfortunately science doesn’t seem to
have much to do with it. 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 beofre changing your grounds around and then bring them up slowly. Put a speaker re-coner out
of work today!