Page 14
Delta Series – Non-DSP Models Operating Instructions
Operating Your Amplifier: Front Panel Controls and Indicators
1: Analogue level controls: These function in both analogue input and network audio input
mode. To switch modes, use the rear panel switch as explained further on page 18.
2: Signal meters: These will show the level of the respective amplifier’s output channel. The
red LED in the meter will illuminate when the limiter threshold has been reached and limiting
is occurring.
3: Link LED: This indicates if the channel is linked to its immediate neighbour. If this is
illuminated, the attenuation control of the channel to the immediate right will not function as
both channels are being fed from the left hand channel. The link switches are on the rear
panel — see page NN for details. Linking is disabled in Network Audio mode and Link LEDs
will be extinguished.
4: PROTECTION LED: If a condition exists, either internally or externally, that could cause
damage to either the amplifier or the speakers, the protection circuit will disengage the
outputs and this LED will illuminate/flash.
Typical conditions that could cause the protection to be triggered include very high frequency
or subsonic input signals, DC in the inputs, short-circuited outputs, or internal high
temperatures.
The protection circuit can affect all channels or a ‘channel pair’ depending on the type of
fault. This is indicated by the combination of Protection LED illuminating and a corresponding
message on the LCD. In this way, it is possible for two channels (a channel pair) to remain
functioning even though a fault has caused the other channel pair to mute. A channel pair
would be 1+2 or 3+4.
Temperature related faults will reset automatically if the unit has cooled sufficiently. Output
short circuits will require manual reset after clearing the fault (switching off at the mains
switch and then on again after a few seconds). Short circuits on either channel of a channel
pair will only affect that channel pair.
5,6: BRIDGE pair LEDs: The channel pair LED will illuminate if these channels have been
switched into bridged (mono) mode. See page 11 for details of how to connect your speaker to
a bridged channel pair, and page
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for how to enable bridge
mode.
7: STBY LED: The power amplifiers in the Delta 80 can be powered down leaving just the
input circuitry and Dante network audio card (if fitted) active. This LED illuminates when the
power amplifier sections are turned OFF.
8: Power Switch: This double pole switch turns the amplifier fully off and isolates it from the
mains supply.
P ROTECTION
BRIDGE 1+ 2
BRIDGE 3+ 4
P OW ER
LIM
3
6
12
18
24
LIM
3
6
12
18
24
LINK
LIM
3
6
12
18
24
LIM
3
6
12
18
24
LINK
LINK
-12
-6
-20
-4
-2
0dB
-12
-6
-20
-4
-2
0dB
-12
-6
-20
-4
-2
0dB
-12
-6
-20
-4
-2
0dB
ANALOGUE
NETW ORK AUDIO
DELTA S ERIES
NETWORK AUDIO POWER AMPLIFIER
S TBY
2
1
3
5
6
7
8
9
10
11
4
