The 100 watt per channel, four-channel MA 4 amplifier achieves unparalleled power density, reliability and features in a space saving 1U, 19 inch rack mount chassis weighing only eight pounds (3.6 kg). A universal-voltage switching power supply provides near perfect Power-Factor, reducing peak currents to ⅓ compared to non power-factor-corrected supplies. A long list of unique features ranging from constant load power to built in automatic redundancy switching to advanced dynamics control, qualify the MA 4 for the most demanding fixed installation applications. The MA 4 excels in Music & Paging systems, small conference rooms and speech reinforcement applications requiring multiple amplifiers. Advanced dynamics control algorithms adapt to changes in temperature, load impedance and sensitivity setting. The result is a truly plug-and-play amplifier that ensures excellent signal integrity at all times.
Don't let those extra connections and switches intimidate you.
The MA 4 is a high-quality general-purpose amplifier and connects like any other.
Remote Level Control inputs are provided for each channel.
To operate an amplifier channel in low power standby with remote turn-on, set its rear panel switch to SLAVE. External +5 volts connected to the FAULT FLAG holds the amplifier in standby. Floating the FAULT FLAG or connecting it to ground turns the channel on.
If you wish to have an amplifier channel report a fault to a control system or back up amplifier, set its switch to Master.
Individual FAULT FLAG ports are provided for each channel. The Fault Flag is held high (+5 volts) during normal operation and goes low (passive pull down) when a fault occurs. A detected fault is re-tested every 10 seconds.
Possible faults include: supply under-voltage, over-voltage, voltage imbalance, output short to ground, output short to supply, output short to output, clock not running, over safe temperature.
The optional VR 2 wired Remote Control allows Level control from within the Zone area. Range is 0 to -80 dB.
To control more than one Remote Port with a single Remote control, it is only necessary to connect the Vc pin of each additional port.
Turn the power to the unit off until all connections are made. Connect the VR 2's control voltage Vc (wiper) connection(s) first. Then connect the Vr voltage reference. Connect the GND (ground) terminal last. Double and triple check your wiring before applying power to the MA 4 since improper wiring can and will cause permanent, irreparable damage to the pot.
Remote Mounting
The VR 2 remote assembly mounts in a standard U.S. electrical box with a minimum depth of 2.25" (5.5 cm). Install any Decora plate of your choice. For a secured installation, you may wish to leave the knobs off and use a blank Decora plate to cover the remote after adjustment.
Wire Types
Variations in wire type do not greatly affect the performance of the remote controls. However, 22-gauge stranded wire with a flexible jacket is recommended. You may use 3-conductor unshielded remote control signal cable for shorter runs (less than 200 ft.) or 2-conductor (1 pair) shielded remote control signal cable (use the shield as the GND return) for longer runs (200 to 1000 ft.). The type of wire required is influenced by your installation and local electrical codes.
Rane Corporation does not provide or source cable. Please contact your local retail or wholesale outlet, not the factory. The following is a short list of suitable cable types:
CONSOLIDATED ELECTRONIC WIRE AND CABLE
The MT 4 four-channel distribution transformer is packaged in a space saving 1U, 19-inch rack-mount tray. The fully isolated, high-performance toroid transformers provide flat frequency response within 1 dB from 40 Hz to 20 kHz. Each transformer is designed for an 8Ω 100 watt input, and 100 watt 70 volt or 100 watt 100 volt output. The recommended load for the 70 volt tap is 50 Ω. The recommended load for the 100 volt tap is 100 Ω. Convenient Euroblock connectors are provided on the rear of the chassis.
The MT 4 comes ready-to-use with four mounted transformers and strain-relief Euro connectors. The tray with Euroblock connectors (model KT 4) and individual transformers with mounting hardware (model TF 4) are available separately, allowing the installer to build a tray with just the number of channels required. This makes this ideal for any rack system that needs high-performance 100 watt, 100 / 70 volt, isolated distribution transformers.
For 25 volt audio distribution systems, the TF 4 can be used by connecting the 25V loads between its 70V and 100V taps (green and yellow wires). Thermal resistance of the TF 4 is only 1C/W and is lower when mounted in a MT 4 chassis.
Other creative combinations are possible. For example, the yellow/green pair can drive 8Ω loads near to the amplifier, with the red/yellow pair being simultaneously used for a 70 V system. Depending on loading of the 70 V system, this arrangement presents an impedance between 4 and 8Ω to the amplifier.
The TF 4 Transformers can be used at power ratings much higher than 100 W, provided that the low-cut frequency is moved up accordingly. Since voltage capability doubles with each octave, power capability quadruples each octave.
MA 4 Amplifier Data Sheet MT 4 Transformer Data Sheet / Manual VR 2 Remote Data Sheet / Manual MA 4 Amplifier Manual
RaneNote: "Sound System Interconnection" RaneNote: "Setting Sound System Level Controls" RaneNote: "Constant-Voltage Audio Distribution Systems" RaneNote: "Unwinding Distribution Transformers" RaneNote: "LEED and the MA 4 Multichannel Amplifier"Can I feed all channels the same signal just by connecting to one of the channels?
No. You can use jumpers to connect all input channel connectors (plus and minus required).
My system seems a bit noisy running through the amp. Is there something wrong with the equipment?
Not likely. The most common misconception is that amplifiers must be turned up all the way to achieve maximum output. This is simply not the case. Most amplifiers will reach full output (and clip accordingly) with sensitivity controls set between 12 and 2 o'clock when fed a + 4 dBu signal. Try turning down your amp(s) and verifying the clipping point. This can make a drastic improvement in reduction of noise.
For runs up to 200 feet any five conductor wire, 22 gauge or larger, will suffice. Use shielded wire for distances greater than 200 feet.
RaneNote: "Sound System Interconnection" RaneNote: "Setting Sound System Level Controls" RaneNote: "Constant-Voltage Audio Distribution Systems" RaneNote: "Unwinding Distribution Transformers" RaneNote: "LEED and the MA 4 Multichannel Amplifier"If the above options don't answer your question, or it's urgent...
Phone 425-355-6000, 8 AM to 5 PM PST, Monday through Friday.
If it's less urgent, you can email the factory.
For local service within the USA, find a service center.
MT 4 high res rear RGB JPG
MA 4 front DWG