Rane FDA 28 User Manual

OPERATING / SERVICE MANUAL FDA 28

QUICK START

This section is provided as a convenience for those in a rush. If you are experienced with this

unit or other Rane Flex modules, these few words should help refresh your memory.

Inputs may be microphone or line level. The choice between the two is made by setting the
pushbuttons on the rear of the unit near each Input. Follow the silkscreening for proper wiring
hookup. Choose between chassis, signal ground or open for shield connection.

Signal for the Outputs is sourced either before or after the A and B MASTER level controls.
The switches which determine this are located within the confines of the unit’s covers. All FDA
28s are shipped from the factory with the internal switches in the POST fader position.

Once Inputs and Outputs are satisfactorily connected, set the Input GAINs as high as possible
without causing the A and B OverLoad indicators to illuminate steadily for high input levels. If 1
x 8 Mono operation is required, use only one Input and set all STEREO/MONO switches to the
MONO position. 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. See the full explana­tion of the power supply requirements elsewhere in this manual.

DISTRIBUTION

AMPLIFIER

SYSTEM CONNECTION

When connecting the FDA 28 to other components in your system for the first time, leave the

power supply for last. This gives you a chance to make mistakes and correct them without damage

to your fragile speakers, ears and nerves.

INPUTS. The two Inputs on the FDA 28 are balanced. They may also be used in an unbalanced

configuration. Use only shielded cable for Inputs. This wire should always be two-conductor plus
shield, even for unbalanced operation. Balanced Inputs should be connected to both the “+” and “–
” terminals. Tie the shield to either chassis ground for normal use, or to signal ground when using
Phantom Power (required). A neutral ground is not necessary (except when using Phantom Power).
For unbalanced use, connect the hot side of the input cable to “+” and ground to signal ground. If
the input is coming from another piece of equipment in the signal path, connect the shield only at
the receiving end to help prevent ground induced hum. If a microphone is being connected to the
unit, the shield may be connected to the case of the mic as well as to the ground terminal on the
unit.

OUTPUTS. The FDA 28s Outputs are balanced. The same wiring conventions as the Inputs

apply, with one exception. Unbalanced Outputs require tying the “–” Output to Signal Ground.

FRONT PANEL DESCRIPTION

The FDA 28 is a combined Stereo or Mono unit. Outputs are labelled in white,
1A/B - 4A/B for STEREO use, and in gray, 1-8 for MONO operation. Note that in
MONO the odd Output Channels are connected to INPUT A and the even Output
Channels to INPUT B.

1. INPUT GAIN CONTROLS. These concentric controls set the Gain of each Input

to be routed to the A and B bus for Stereo operation, or to the odd and even buses
for Mono use. The inner knob controls the level to be sent to bus A (odd), the outer
knob controls the signal applied to bus B (even). Rotating the knobs upward
together from the MIN position creates a “pan centered” effect. Leaving one off and
increasing the other emulates a full pan to one bus or the other.

2. A AND B OVERLOAD INDICATORS. These red LEDs illuminate whenever the

combination of Input level and Input GAIN adjustment cause the input amplifiers to
reach or exceed a level equal to 4dB below clipping.

3. MASTER A AND B LEVEL CONTROLS. These concentric controls set the level

to each of the post buses. Output levels may be selected via the four pairs of
controls connected to the Output sections if the internal PRE/POST switches are in
the POST position (as shipped).

In the PRE position, the MASTER Level control is bypassed for that respective

Output and only the Input GAIN Control and the OUTPUT Level Control have any
effect on an individual Output.

4. STEREO/MONO SWITCHES. To make one or both Inputs drive all eight

Outputs, slide all switches to their MONO positions. In STEREO mode, INPUT A
drives bus A (or odd) only; INPUT B connects to bus B (or even) only. Program
each pair of Outputs as necessary. Monoing one Output pair will have no effect on
the other Outputs.

5. OUTPUT LEVEL CONTROLS. Each pair of OUTPUT controls sets the indi-

vidual Channel Output levels. The inner knob is for Channel A (or odd), the outer is
Channel B (or even).

6. POWER INDICATOR. 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.