REAR PANEL DESCRIPTION
1. INPUT TERMINALS.
Use these for either a microphone or a line level input to be dis-
tributed by the FDA 18. Connect a balanced source to the respective “+”, “–” and GND
pins (pins 2, 3 and 1 respectively). An unbalanced input should connect to “+” and GND
only. When using an unbalanced input, you may leave “–” open, or short it to GND, doesn’t
matter.
2. OUTPUT TERMINALS.
Balanced output for each channel. Connect two-conductor
shielded cable to “+” and “–”. Normally the shield is tied only at the next unit’s input.
For unbalanced use, you must ground the “–” output, Failure to do so results in im-
proper operation.
3. GROUND LIFT SWITCH.
This switch (mounted on the side) provides the ability to sepa-
rate chassis ground and signal ground. Normally, this switch should be in the LIFT position
(pull toward the rear). 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 BEFORE
CHANGING YOUR GROUNDS AROUND and then bring them up slowly.
4. POWER INPUT CONNECTOR.
USE ONLY A MODEL RS 1, FRS 8, RAP 10, OR
OTHER REMOTE AC POWER SUPPLY APPROVED BY RANE. The FDA 18 is supplied
with a remote power supply suitable for connection to this input jack. Consult the factory for
replacement or substitution.
5. CHASSIS GROUND POINT.
A 6-32 threaded hole used for chassis grounding purposes.
See the CHASSIS GROUNDING note on the last page for details.
NOTE: ASSIGN SWITCHES SHIPPED IN “POST” POSITIONS
