Rane MA 6 User Manual

Professional Audio Products

Model MA 6 Multichannel Amplifier

General Description

The Rane Model MA 6 Multichannel Amplifier supplies
six completely independent amplifier channels in one 3
space rack mount unit. Each channel is capable of providing
100 Watts rms, to an eight ohm load or 150 Watts each into
a four ohm load. Adjacent pairs of channels (l&2, 3&4, 5&6)
may be bridged so the pair will provide up to 300 Watts into
an eight ohm load.

Each channel of the MA 6 includes an input limiter circuit.
This limiter has been carefully designed to prevent overload

(clipping) from occurring at the output of the amplifier,
while, at the same time, doing so in a transparent manner.
This limiter provides an additional 15 dB of headroom to
each channel, making the 100 watt ratings effectively much
higher.

is contained on its own circuit board assembly making it im­pervious to the actions of any other channel. Power is dis­tributed to each channel from one master power supply,

howevcr the power supply is designed so that signal may not
back-feed from a heavily loaded channel to any other chan­nel, making power supply cross talk between channels in­audible.

sembly affords a high level of mechanical integrity, even when
the amplificr is rack-mounted and unsupported in the rear.
As an added benefit, mounting holes arc provided on the side
rails so the amplifier may be supported from the back.

MA6

MULTICHANNEL AMPLIFIER

All channels of the MA 6 are completely independent; each

Heavy gauge all-steel construction of the MA 6 chassis as-

Features

• SIX INDEPENDENT AMPLIFIERS

• 100 WATTS PER CHANNEL @ 8 OHMS

• 150 WATTS PER CHANNEL @ 4 OHMS

• 300 WATT BRIDGED PAIRS @ 8 OHMS

• INPUT LIMITERS ON EACH CHANNEL

• SIGNAL PRESENT INDICATORS

• LIMITER STATUS INDICATORS

• OVERLOAD / CLIP INDICATORS

• INPUT LEVEL CONTROLS

• 3-SPACE RACK MOUNT CHASSIS

• HEAVY GAUGE STEEL PACKAGE

• EXTRA STRENGTH POWER SUPPLY

• AUTOMATIC 2-SPEED FORCED AIR COOLING

Applications

• MULTI-ZONE SOUND SYSTEMS

• STAGE MONITORS

• BI-AMP/TRI-AMP SYSTEMS

• RECORDING STUDIOS

• SIGNAL DISTRIBUTION SYSTEMS

• BROADCAST MONITORS

• PAGING SYSTEMS

• HOTELS

• RESTAURANTS

• CINEMA SURROUND-SOUND SYSTEMS

MA 6

MULTICHANNEL AMPLIFIER

Features and Specifications

Parameter
Power Output

Inputs: Type.

Connectors

....... Impedance

Maximum Level
Sensitivity

Outputs: Type

Connectors

....... Damping Factor

....... Minimum Load

On/Off Transient Muting

Fan Cooling
LED Threshold: Signal Present

Limit

............... Fault

Ultrasonic Filter
Frequency Response
THD + Noise

IM Distortion (SMPTE)

Signal-to-Noise Ratio
Crosstalk
Limiter: Type

....... Range

Max Input @ Clipping

....... Attack Time Constant

Decay Time Constant

Detection

Maximum Power Useage
Line Voltage: Domestic

.......... Export

Unit: Construction

Size
Weight

Shipping: Size

Weight

Note: 0 dBu = 0.775Vrms

Specification

100

150
300
Active Balanced/Unbalanced
l/4" TRS

9.7k

+20
Off to 0 dBu (Adjustable)
Direct Coupled
Terminal Blocks
300:l
No Less Than 4 Ohms
No Less Than 8 Ohms
Yes, Output Relays

Yes, 2-Speed Thermostat

-20
90
270
Clipping, Ultrasonics, or any
Failure to Accurately
Reproduce the Input Signal
80 kHz, 12 dB/Oct
5-80 kHz

0.2

0.1
96

-60
Servo-Locked™ Input VCA
15

+15
10
10
Full-Wave Peak
1800
95-130 VAC, 50/60 Hz
190-250 VAC, 50 Hz
All Steel

5.25"H x 19"W x ll"D (3U)
44 lb
11" x 23" x 16"
48 lb

Units Conditions/Comments

All Channels Driven, 20-20k Hz
W
W
W

ohms
dBu
dBu Input Rqd. For Rated Power Out

dBu

W
W

Hz
dB
%
%

dB
dB

dB
dBu
ms
ms

W

(6) 8 ohm Loads

(6) 4 ohm Loads

(3) Bridged Pairs into 8 ohms

1 kHz

Single Channel Operation
Bridged Operation
Activates approximately 10 seconds

after power is applied, drops out

immediately after turn-off; drops

out any time there is DC or large

subsonic signals.

Intake Rear; Exhaust Front

Input Level
8 ohms, Single Channel Operation
8 ohms, Bridged Operation

100 W /8 ohms, 1 kHz

60 Hz /7 kHz, 4:1
re 100 W /8 ohms, A-Weighted

1 kHz, Any Channel to Any Channel

(13.3cm x 48.3cm x 27.9cm)

(20 kg)

(27.9cm x 58.4cm x 40.6cm)

(21.8kg)

Block Diagram

Professional Audio Products

MA 6

MULTICHANNEL AMPLIFIER

Application Information

Affectionately known as the 900 watt six-pak, Rane’s MA 6
is a powerhouse of flexibility. The MA 6 innovative concept
in power amplifier design offers many distinct advantages
over standard two-channel units. Although the idea of six
100 watt amplifiers in one box takes a little getting used to, it
will soon become apparent just how desirable this configura­tion is for a wide variety of applications.

The MA 6 provides an unprecedented degree of flexibility:
a) Use it as a monitor amplifier for six separate channels of
stage monitor mixing; b) Drive a pair of two-way speaker sys­tems, bi-amped with two bridged pairs at 300 watts for the
low end and two 100 watt channels for the high end, each with
limiters for driver protection; c) Run three bi-amped
monitors at 100 watts each; d) Drive three passive two-way
monitors at 300 watts each. A single MA 6 will handle any of
these situations and many more at a fraction of the cost, size
and weight of the equivalent number of two-channel
amplifiers.

Do not underrate the performance capability of 100 watts

with a limiter. Each yellow Limit LED on the MA 6 front
panel lights to show peaks above 100 watts which would have
otherwise caused clipping – yet all program under 100 watts
is completely unaffected. This kind of limiting allows each
channel to be run more closely to rated output without clip­ping more than doubling the actual sound output. (See ac­companying graph.)

Field measurements show a minimum 4 dB increase in con-

tinuous SPL, which is the equivalent SPL of a 250 watt

amplifier without limiting. As many customers have

proclaimed, “This is the loudest 100 watt amplifier, I’ve ever
heard.”

The MA 6 is housed neatly in an all-steel chassis with hefty
12-gauge side rails to withstand continuous heavy road use.
The power supply and massive heatsink are efficiently cooled
with a thermostatically controlled two-speed fan for stringent
thermal stability and resultant long-term reliability.

Take a moment to think about this fascinating 900 watt six-

pak. It could do amazing things for your system.

The Limiter Performancegraph, below, illustrates how well
the MA 6 protects itself from overload while providing an ad­ditional 15 dB of headroom. The horizontal axis is scaled as

relative input level; the vertical axis indicates output power.
As the input approaches the level required to clip the un­protected amplifier, the limiter engages and provides a
smooth 100 watt power output until the +15 dB input level is

MA 6

MULTICHANNEL AMPLIFIER

Rear Panel Details

Architectural Specifications

The power amplifier shall be a multichannel unit consisting
of six (6) independent power amplifiers. Each amplifier shall
be able to deliver 100 watts into 8 ohms, or 150 watts into 4
ohms with all channels loaded. In addition, bridged pairs

shall be able to put out 300 watts each into 8 ohms, all chan­nels driven.

Each amplifier channel shall be supplied with an input at-

tenuator type limiter to provide an additional 15 dB of
headroom beyond full power output. A full-wave peak detec­tion scheme shall be utilized with 10 ms attack and release
characteristics.

A thermostatically controlled two-speed fan shall be sup­plied, drawing air into the rear of the unit and exiting through
the front.

Input level controls calibrated in dBu for full power output
shall be included. Output relays shall be provided to control
turn-on, turn-off and subsonic muting.

Ultrasonic filters shall be built-in, and LEDs provided to
indicate Fault, Limit and Signal Present conditions.

The inputs shall be active balanced/unbalanced designs ter­minated with 1/4" TRS (tip-ring-sleeve) connectors. The out­puts shall be active unbalanced terminated in terminal
blocks.

The unit shall be capable of operation by means of its own
built-in power supply connected to 120 VAC (240 VAC
where applicable). The unit shall be entirely constructed
from cold-rolled steel.

The unit shall be a Rane Corporation Model MA 6.

Available Accessories

• BB 6 BANANA BRACKET ADAPTER KIT

• MT 6 MULTICHANNEL TRANSFORMER SYSTEM

References

1. T. Pennington, “Design and Applications of a Multi-Channel Power Amplifier,” presented at the 80th Convention of the

Audio Engineering Society, Montreux, Switzerland, Mar. 4-7, 1986, preprint no. 2345.

2. D. Bohn, “MA 6 Limiter Operation,” RaneNote 103, (1983).

3. T. Pennington, “Everything You Always Wanted To Know About Six” RaneNote 105, (1983).

4. D. Bohn, “Cinema Sound System,” RaneNote 114, (1986).

5. T. Pennington, “Cost-Effective Noise Masking Systems,” RaneNote 116, (1987).

6. T. Pennington, “Distributed Factory Sound,” RaneNote 119, (1988).

Copyright 1988, Rane Corporation 10802 47th Ave. W. Everett, WA 98204 [phone]