Data Sheet-6
MA 4
MULTICHANNEL AMPLIFIER
Power-Factor-Correction (PFC)
Near perfect Power-Factor with ⅓ the peak current and ½ the
average current (green) compared to non power-factor-corrected
supply with conduction of 3 ms (black). e response is mea-
sured at 100 watts.
Architectural Specifications
e unit shall be a four channel amplier. It shall deliver 100
watts of power per channel into a 4 to 8 ohm load. e ampli-
er shall incorporate load sensing with normal operation in the
range of 2 to 16 ohms. Front panel indicators shall alert presence
of a channel load outside of this range.
e amplier shall have balanced inputs with Euroblock
connectors and Euroblock output connectors capable of accept-
ing 12 gauge wire. Sensitivity controls with a range of +22 to +4
dBu shall be provided for each input on the rear panel by means
of screwdriver adjustment. Load sensitive headroom meters shall
provide indication of 3, 6, 12 and 24 dB of remaining headroom.
Euroblock connectors shall be provided as a means of con-
necting remote DC level potentiometers or switches to attenuate
the input level of each channel.
Automatic redundancy switching shall be provided in the
event of a fault of any amplier channel. Euroblock connectors
shall provide a means of connecting additional amplier outputs
for automatic backup purposes. Each channel shall have master
or slave operation determined by a rear panel dipswitch. Master
channels shall write fault ag status, and Slave channels shall
read fault ag status.
A rear panel dipswitch shall provide a selection of 20, 40, 60
or 80 Hz highpass 2nd-order Butterworth lters. Load sensitive
limiter circuits shall prevent clipping and the associated loss of
speech intelligibility. A front panel LED shall indicate limiter
activity within each channel.
Built-in compressors shall be provided with a 10 dB thresh-
old. A rear panel dipswitch shall activate or deactive the com-
pressors. A front panel LED shall indicate compressor activity
within each channel.
Built-in expanders shall be provided with a -70 dBFS thresh-
old. A rear panel dipswitch shall activate or deactive the expand-
ers. A front panel LED shall indicate expander activity within
each channel.
Euroblock connectors on the rear panel shall provide a means
of transmitting or receiving fault ag information to other
ampliers or indicators with an active 5 volt drive. A front panel
LED shall indicate a fault ag condition within each channel.
ermal management shall employ forced air cooling, allow-
ing the ampliers to operate reliable in ventilated racks at 40°C
ambient temperature. e fan speed air ow shall be controlled
by temperature. Intake shall be on the left side of the chassis and
exhaust on the right side, incorporating low velocity air ow to
minimize noise within a rack cabinet.
e universal internal switch-mode power supply shall
operate from 100 to 240 VAC, 50 or 60 Hz. e power supply
design shall provide power-factor-correction with very low inrush
current and overvoltage protection. An IEC connector and IEC
cord shall be utilized. A front panel mounted power switch shall
be provided.
e unit shall be a Rane Corporation Model MA 4.
Compressor Response
Output dB re 100W
O
u
t
p
u
t
P
o
w
e
r
Attack: 1.5 seconds
Release: 3 dB per second
Output Power
Output dB
Input dBu
