Data Sheet-3
MA 4
MULTICHANNEL AMPLIFIER
MA 4
100-240V
50/60 Hz 500 WATTS
RANE CORP.
Class 2 Wiring
OUTPUTS
Active Low
Use Rane VR 2 or 20 k
Ω
pot
HIGH-PASS
20Hz
40Hz
60Hz
80Hz
ON
4
+ – + – + – + –
+ – + – + – +
REMOTE LEVEL
4
4
FLAG
3
2
1
FAULT
Vr Vc
Vr Vc
Vr Vc
Vr Vc
–
+ – + – + – + –
+ – + – + – + –
3 2 1
MASTER
SLAVE
COMP
4 3 2 1
1 2 3 4
+ –
+ –
+ –
+ –
Vr Vc
Vr Vc
Vr Vc
Vr Vc
+ –
+ –
+ –
+ –
INPUTS
MODE
13
22
dBu
SENSITIVITY
4
3
13
22
dBu
SENSITIVITY
4
2
13
22
dBu
SENSITIVITY
4
1
13
22
dBu
SENSITIVITY
4
EXP ON
3
INT EXT
LOAD
2
INT EXT
LOAD
1
INT EXT
LOAD
4
INT EXT
LOAD
COMMERCIAL AUDIO
EQUIPMENT 24TJ
R
FOR CONTINUED GROUNDING
PROTECTION DO NOT REMOVE
THIS SCREW.
4
3
2
1
ON
4
3
2
1
ON
1
2
4
6
9
0q
5
7
8
3
1
Universal voltage, power-factor corrected, switch mode power supply operates 85 to 260 VAC, 50 Hz or 60 Hz. The supply
features under and over voltage protection, low inrush current and operates with up to 85% efficiency.
2
INPUTS are balanced and accept up to +22 dBu via Euroblock connectors with strain-relief.
3
SENSITIVITY controls allow continuous adjustment from +22 dBu to +4 dBu. Integrated limiter prevents clipping regardless of
input level and sensitivity setting.
4
REMOTE DC LEVEL control ports with Euroblock strain-relief connectors allow audio taper attenuation using 10k to 100k Ω
linear pots. Clickless muting may be implemented using a switch, connecting Vr to Vc.
5
A soft knee COMPressor is provided with rms threshold relative to the limit threshold. ON/off setting affects all channels. This
allows uncompressed operation with typical program material while reducing continuous sine-wave power. Ratio is 3:1; Attack is
1.5 seconds; Decay is 3 dB per second; Soft knee span is 10 dB.
6
Downward EXPander reduces noise in the absence of signal. ON/off setting effects all channels.
º Threshold: –70 dBFS; Ratio: 3:1; Attack: 50 ms; Gain reduction: 10dB/sec.
7
Selectable 20 Hz, 40 Hz, 60 Hz or 80 Hz HIGH-PASS filters are provided. The setting affects all channels. Filters are 12 dB per
octave, Butterworth alignment.
8
Each channel is set for MASTER or SLAVE operation. Master channels write Fault Flag status. Slave channels read Fault Flag
status.
• The Master setting is used for remote fault reporting and/or automatic redundancy switching control.
• The Slave setting is used for individual channel remote power sequencing or automatic redundancy switching.
9
Individual FAULT FLAG ports are provided for each channel.
• The Fault Flag uses high-side active drive and passive pull down. No fault = +5 volts. Fault = 0 volts.
• Channels set to Master drive the Fault Flag high when no fault is present. Passive pull down pulls the Fault Flag low when a
fault occurs or power is lost.
• Slave channels read the status of the Fault Flag.
0
Amplifier outputs are floating (not ground referenced) and are
not
bridgeable. Each channel delivers 100 watts into a 4 or 8Ω
load. Average load impedance is estimated then used to determine the limiter threshold required to limit maximum power to 100
watts and peak current to less than 7.5 amps. Impedance estimation requires a minimum of 3.3 watts and is averaged over 180 ms.
q
External amplifier input is used for Internal, automatic redundancy switching.
w
Comprehensive front panel metering is included for each channel:
• Four segment, load sensitive headroom meter shows remaining headroom.
• Limiter, Compressor and Expander indicators light when the associated dynamics control is active.
• The Fault indicator lights when a fault is detected
• The Load indicator if
off
when impedance is above 16Ω,
on
when impedance is between 2 and 16Ω and
flashing
when the
impedance is below 2Ω.
• The Ready indicator is
off
when the power switch is off,
flashing
when the power is switch is ON and the unit is in standby
(Slave channel with high fault flag) and
on
when the channel is active.
dB Headroom
dB Headroom
dB Headroom
dB Headroom
3
6
12
24
Limit
1
Comp
Exp
Fault
Load
Ready
3
6
12
24
Limit
2
Comp
Exp
Fault
Load
Ready
3
6
12
24
Limit
3
Comp
Exp
Fault
Load
Ready
3
6
12
24
Limit
4
ON
Comp
Exp
Fault
Load
Ready
w
