1
10. Channel SIGNAL/LIMIT Indicator
This LED glows in GREEN color to show the presence of the signal at the correspondent amplifier channel.
This LED glows in RED color when the DSP is limiting the channel’s output or when the channel input is clipping.
NOTE:
in case of input clipping you have to reduce the input signal in the signal chain before the amplifier input.
11. Channel PROTECT Indicator
RED LED glows when the correspondent channel is in protect mode for one of the following reasons:
• The heatsink reaches a temperature above the normal working limit.
• There is a short circuit at the amplifier output wires.
• The amplifier output stages are faulty.
Consequently the channel is muted until the reason of fault is removed.
NOTE:
When the channel pair operates in PARALLEL and BRIDGE mode SIGNAL, LIMIT and PROTECT LED indicators of
the channel pairs 1-2 or 3-4 illuminate simultaneously.
12. Input Channel LEVEL Control
This control reduces the level of the signal sent to the correspondent channel after the A/D conversion and before any
channel sum (PARALLEL or BRIDGE modes) and any DSP processing.
The reduction ranges from “∞” fully closed (the signal is completely attenuated) to “0” fully open, nominal level.
1. INPUT
This is a female combo connector, which accepts a XLR or a JACK plug from almost any type of equipment with a
balanced or unbalanced outputs. The XLR input is wired as follows:
Pin 1 = shield or ground
Pin 2 = + positive or "hot"
Pin 3 = - negative or "cold"
The JACK input is wired as follows:
Tip = + positive or "hot"
Ring = - negative or "cold"
Sleeve = shield or ground
When connecting an unbalanced signal, wire them as follows:
Pin2 / Tip = + positive or "hot"
Pin 1-3 / Sleeve = shield or ground
NOTE:
whenever possible, use always balanced cables. Unbalanced lines may also be used but may result in noise over
long cable runs. In any case, avoid using a balanced cable for one channel and an unbalanced one for the other.
14. LINK
This is a male XLR connector is connected in parallel with the respective INPUT (LINK is wired in the same way).
1. GND LIFT
This switch lift the ground of the balanced audio inputs from the earth-ground of the amplifier. If you have HUM noise
problems on one or more loudspeakers try to change the position of these switches.
16. Channel 1 or 3 SPEAKON output
Accepts a male Neutrik Speakon NL4FX connector wired in this way:
• PIN 1+ connected to POSITIVE output of Channel 1/3;
• PIN 1- connected to NEGATIVE output of Channel 1/3;
• PIN 2+ connected to POSITIVE output of Channel 2/4,
• PIN 2- connected to NEGATIVE output of Channel 2/4,
If you use a 2 wire cable (1+/1-), you run to the speaker the amplified output of the signals coming from inputs 1 or 3.
If you use a 4 wire cable (1+/1-/2+/2-), you run to the speaker:
• STEREO mode: the amplified outputs of the signal coming from 1/3 input (1+/1-) and from 2/4 input (2+/2-),
• PARALLEL mode: the amplified outputs of the signals coming from 1+2 or 3+4 inputs (1+/1- and 2+/2- carry the same
signal),
In both modes using a single cable you can connect a BI-AMP loudspeaker or a SUB-SAT speaker system.
Always connect a loudspeaker with a minimum impedance of 4 ohm or more.
NOTE:
Use only loudspeaker enclosure cables, never signal cables, i.e. those normally used for microphones, instruments
and audio equipment in general.
