MRA-2 & MRA-4 Installation Manual
Configuration and Set-up
04
Configuration and Set-up
05
Configuration and Set-up
Before connecting the amplifier it is advisable to set the configuration switch, just above the LINE IN sockets on the rear panel, to suit
the installation requirements.
Note:
Changes in the configuration switch settings will have no effect if changed while the amplifier is switched ON. Changes to the
switch settings should be done with the unit switched OFF.
- Music Sensing
Both the MRA-4 and MRA-2 contain a sophisticated music sensing circuit which causes the amplifier to switch from "standby" to "active"
in the presence of an audio signal. The switch ON is almost instantaneous, and in most installations should be the preferred mode of
operation. For the MRA-4 both Amplifier 1 and Amplifier 2 music sensing operate independently; so a signal present at AMP 1 LINE IN
will not activate Amplifier 2 and visa versa.
When the amplifier detects that no audio signal has been present for around 2 and one half minutes it will automatically switch to
standby
(ALL LEDs off )
until the LINE IN signal becomes active again.
When an audio signal is detected at either the Right or Left LINE-IN socket, the amber Signal LED will illuminate on the front panel
indicating signal presence, and the amplifier will switch ON.
Note:
The Signal present LED will turn OFF during levels of extremely low signal input and between "tracks" when the output is muted.
The factory shipping position for MUSIC SENSING is ON.
To switch the music sensing feature OFF, move the MUSIC SENSING top switch to the OFF (right) position.
When MUSIC SENSING is set OFF the amplifier will
always be active whilst the unit is connected to the
mains supply and the front panel Power Switch is ON.
In this mode the amplifier will show which speakers
are selected via the green LED speaker pair 1 and 2
indicators on the front panel.
12
3
4
ON
ECE
LINE IN
L I N E O U T
A M P 1
LINE IN
L I N E O U T
A M P 2
R
L
MUSIC SENSING
ON/OFF
COM-INPUT
- Common Input (MRA-4 Only)
In an installation where all four speaker outputs are required to act as a single zone, the MRA-4 incorporates a feature to simplify the
connection of both Amplifier 1 Right & Left LINE IN and Amplifier 2 Right & Left LINE IN to the same stereo signal. This prevents the need
for extra phono leads or "Y" adapters. This feature should only be used when you want Amplifier 1 and Amplifier 2 to play the same source.
To switch this feature the ON, move the COM - INPUT switch to the (left) ON position.
The factory shipping position for Common Input operation is OFF.
Note:
When MUSIC SENSING is ON in and COM - INPUT is ON both
Amplifier 1 and Amplifier 2 will switch ON and OFF in synchronisation.
- Line Input Connections
Using the MRA-2 and MRA-4 with a Systemline S4.3 Controller.
Before connecting an S4.3 Controller, it is important to ensure that the S4.3 Pre-amplifier Zone Output to be used with the amplifier is
configured as "Pre-Out" and not "Line-Out".
Note1:
S4.3 controllers are factory set for all zones to be "Pre-Out". Refer to Sections 5.51 and 5.6 of the Systemline S4.3 manual if the
Line Driver configuration needs to be changed.
Using shielded Phono to Phono cables connect the Controller Zone's Pre-Out Right and Left sockets to the AMP
1
LINE IN Right and Left
sockets at the rear of the amplifier.
When installing an MRA-4, a second S4.3 Controller Zone's Pre-Out Right and Left output can be connected to the AMP
2
Right and Left
LINE IN sockets at the rear of the amplifier.
Note1:
When connecting a power amplifier to a Zone's pre-out sockets it is still possible to use the S4.3 Controller's internal amplifier.
This can be useful when driving multiple pairs of speakers from a single controller zone.
Note2:
Only the AMP 1 LINE IN Right & Left sockets should be used to connect the audio source when using the Common Input feature
on the MRA-4.
MRA-4
LINE IN
L I N E O U T
A M P 1
LINE IN
L I N E O U T
A M P 2
AMP 1 SPEAKERS
PA I R 1
PA I R 2
R
L
A M P 2 S P E A K E R S
PA I R 1
PA I R 2
R
L
MADE IN ENGLAND
SERIAL NO -
MRA4
MULTI CHANNEL ROOM AMPLIFIER
230V
50Hz
POWER CONSUMPTION 600W MAX
I M P O R TA N T: K E E P A L L V E N T S C L E A R O F O B S T R U C T I O N
R
L
MUSIC SENSING
COM-INPUT
I M P E DA N C E- 4 - 1 6
Ω
I M P E DA N C E- 4 - 1 6
Ω
230V T4AH 250V
110V T6AH 250V
MRA-4
S4.3 CONTROLLER
LINE IN
L I N E O U T
A M P 1
LINE IN
L I N E O U T
A M P 2
AMP 1 SPEAKERS
PA I R 1
PA I R 2
R
L
A M P 2 S P E A K E R S
PA I R 1
PA I R 2
R
L
MADE IN ENGLAND
SERIAL NO -
MRA4
MULTI CHANNEL ROOM AMPLIFIER
230V
50Hz
POWER CONSUMPTION 600W MAX
I M P O R TA N T: K E E P A L L V E N T S C L E A R O F O B S T R U C T I O N
R
L
MUSIC SENSING
COM-INPUT
I M P E DA N C E- 4 - 1 6
Ω
I M P E DA N C E- 4 - 1 6
Ω
230V T4AH 250V
110V T6AH 250V
ON/OFF
ON/OFF
Input connections from
S4.3 to MRA amplifiers
MUSIC SENSING SWITCH
MUSIC SENSING
ON/OFF
LINE IN
M P 1
COM-INPUT
SWITCH 1 (MUSIC SENSING ) IS ON
12
3
4
ON
ECE
COMMON INPUT
SWITCH OFF
Conforms to EN55013 & EN50082-1.
E.M.C. Test Certificate No. 300/95
S4.3 MULTI-ROOM CONTROLLER
PRE/LINE-OUT
PRE/LINE-OUT
PRE/LINE-OUT
PRE/LINE-OUT
Conforms to EN55013 & EN50082-1.
E.M.C. Test Certificate No. 300/95
S4.3 MULTI-ROOM CONTROLLER
PRE/LINE-OUT
PRE/LINE-OUT
PRE/LINE-OUT
PRE/LINE-OUT
S4.3 CONTROLLER
