WARNING:
THE MINIMUM SPEAKER IMPEDANCE IS 4
OHMS EACH.
IF YOU CONNECT AND USE THE MA254 WITH A LOWER SPEAKER IMPEDANCE THAN LISTED ABOVE
YOU WILL DAMAGE THE UNIT AND POSSIBLY OTHER
EQUIPMENT THAT IS CONNECTED TO THE MA254.
MA254
5 + 5 watt
Mixer/Amplifi er
SPECIFICATIONS:
Line Input Impedance: 10K Ohms
Power Output: 5 Watts X 2 (4 Ohms)
Voltage Gain: 30 dB Line
Maximum Supply Voltage: 24 VDC
THD: .05% typical
EIN: 3 mV
Effi ciency: 85%
Input Sensitivity: 28 mV
Bandwidth: 20Hz - 25 kHz +/- 3dB
+Size: 6.75" x 3.5" x 1.5"
Weight: 1 lb.
75889 025 40
68
Salt Lake City, Utah
04/10
INPUT
CH 1
MA254
CH 3
INPUT
CH 2
LEVEL
L
R
INPUT
CH 2
CH4
INPUT
CH 4
INPUT
L
R
CH 3
010
LEVEL
LEVEL
CH 3CH 4
OUT
INPUT
LINE
L
R
LINE
MUTE
OUT
010
CH 3CH 4
LEVEL
LEVEL
INPUT
MONO
CH 2
MUTE
CH 2
MONO
INPUT
+
CH 4
+
SPEAKER OUTPUTS
-
RIGHT
010
CH 2
LEVEL
STEREO
3.5mm
RIGHT
-
-
-
LEFT
010
LEVEL
MA251
BOTH OUTPUTS MUST BE USED
LEFT
+
+
CH 1
PS12
5 + 5 WATT MIX/AMP
CLASS AMP
PS12
MADE IN USA
www.rolls.com
AMPMIX
5 + 5 WATT MIX/AMP
LEVEL
CH 1
POWER
PHANTOM
ON - OFF
CH 1
CH 2
INPUT
INPUT
• RCA Inputs for all channels, and Channel 4 -
3.5mm stereo input on the front panel.
• Volume controls for each Channel
• Low noise, effi cient operation
• Small compact size
• Class D high effi ciency amp
The MA254 is a very compact 5 + 5 watt high effi ciency amp with
a four channel stereo mixer built in. Left and Right stereo speaker
outputs. The unit is perfect for small speakers in small environments. Great for in ceiling and projector applications where small
size is needed along with class D low radiated heat locations.
Connection guide
INTRODUCTION
Thank you for your purchase of the MA254. The MA254 is a four channel mixer/
amplifi er designed for Audio and Visual applications. Channel 1-4 have RCA
stereo inputs and channel 4 has a 3.5mm stereo input. The MA254 is intended
for professional applications. It has a FR4(V94-0) rated glass epoxy circuit board,
and a powder coated steel chassis. All inputs are stereo. Outputs for Speaker
and Line are true stereo.
NOTE: THIS MANUAL ASSUMES THE USER HAS A WORKING KNOWLEDGE OF AUDIO ELECTRONICS, BALANCED AND UNBALANCED CONNECTIONS, AND PROPER SIGNAL LEVEL SETTING.
INSPECTION / WARRANTY
1. Unpack and inspect the MA254 box and package.
If obvious physical damage is noticed, contact the carrier immediately to make a
damage claim. We suggest saving the shipping carton and packing materials for
safely transporting the unit in the future.
2. Please visit our web site at www.rolls.com and click on the Register Your Warranty Here button.
DESCRIPTION
REAR PANEL
SPEAKER OUTPUT: Push terminals for speaker wire.
PS12: For connection to the power supply.
INPUTS: RCA line level inputs.
MUTE JACK: By shorting out the RCA jack labeled MUTE, the Speaker Outputs
will be muted.
CH 1
INPUT
POWER
PHANTOM
ON - OFF
CH 2
INPUT
LEVEL
CH 1
LEVEL
CH 2
INPUT
CH 2
L
INPUT
CH 1
R
CH 3
CH4
INPUT
INPUT
CH 3CH 4
INPUT
CH 3
L
R
LINE
OUT
LEVEL
L
R
OUT
LINE
MUTE
CH 2
MUTE
CH 2
MONO
INPUT
INPUT
MONO
LEVEL
+
RIGHT
STEREO
3.5mm
CH 4
RIGHT
+
-
SPEAKER OUTPUTS
-
-
-
LEFT
5 + 5 WATT MIX/AMP
CLASS AMP
MA251
BOTH OUTPUTS MUST BE USED
LEFT
+
PS12
PS12
+
FRONT PANEL
CHANNEL VOLUME: Adjusts the level of signal from the Line Input to the Line
out RCA's and Speaker outputs.
3.5mm JACK: For connection to an ipod, MP3 player or computer TRS Stereo
(left, right and ground) connection to channel 4.
MADE IN USA
www.rolls.com
AMPMIX
5 + 5 WATT MIX/AMP
MA254
CH 4
INPUT
010
LEVEL
010
CH 3CH 4
LEVEL
010
CH 2
LEVEL
010
CH 1
LEVEL
CHANNEL DESCRIPTION
CH 1 INPUT: Stereo RCA jack for connection to a signal source such as a CD
player, cassette deck, tuner, etc.
CH 2 INPUTS: Stereo RCA and one mono RCA for connection to a signal source
such as a CD player, cassette deck, tuner, etc.. PLEASE NOTE WITH A MONO
INPUT AS WELL AS A STEREO INPUT, CHANNEL 2 AT CERTAIN IMPEDANCES ON THE STEREO INPUT YOU MAY EXPERIENCE CROSS TALK BETWEEN THE LEFT AND RIGHT. THIS IS NORMAL OPERATION AND SHOULD
BE EXPECTED.
CH 3 INPUT: Stereo RCA jack for connection to a signal source such as a CD
player, cassette deck, tuner, etc.
CH4 INPUT: Stereo RCA jack for connection to a signal source such as a CD
player, cassette deck, tuner, etc. CH4 also has a front connection for a stereo
3.5mm(1/8” jack).
LINE OUT: Stereo RCA jacks for connection to a mixer or amplifi cation device.
CONNECTION / OPERATION
To operate the MA254, properly connect cords from the sources to be mixed
(cassette decks, CD players, etc.) into the channel inputs. Connect the speaker
outputs to 4 Ohm or higher impedance speakers. Adjust the channel level con-
trols for the desired volume.
5968 S 350 W
Murray Utah84107
Rolls Corporation
MA254 MIXER AMPLIFIER
Title
C14
47U
+B
R5
22K
D1
R8
18K
R21
4.7K
VCC
C13
2200
C12
2200
C11
2200
D2
D3
1N4001
D5
D4
1N4001
231
J1
JAPDC
1N4001
1N4001
Rev:
Size: Document Number:
LDRR
IN 12-24 VAC/VDC
1
1
Sheet of
MA254.SCH A
5 APRIL 2010
Rb
Date:
SCHEMATIC
+ - - +
123
4
J6
PUSH TERMINAL
SPEAKER OUT
C20
1K
R27
C19
L1
47uH
C18
.22uF
18
19
BSL
LIN4RIN5BYPASS6AGND7AGND8VCLAMP
U2
R32
100K
C5
.047
C6
47U
100
R10
120PF
C4
100K
8
V+
R9
6
C3
1U
P4A
P100K X2
P4B
P100K X2
1 3
2
R1
231
J5A
RCAX4 PC
4 6
5
R2
10K
10K
10K
R15
231
J2A
RCAX4 PC
CH 1
1K
C23
4.7K
R28
4.7K
.47uF
C22
.47uF
L2
47uH
C21
.22uF
12
11
13
20
BSR
LOUT
ROUT
PGNDL
PGNDR
GAIN114GAIN0
15
C16
C17
1U
R31
100K
STEREO
C9
.047
J3B
RCAX4 PC
564
7
U1B
5
P1A
2
10K
R14
R13
4560
C8 120PF
4560
R12 100K
+B
1U
C7
P100K X2
P1B
P100K X2
1 3
4 6
5
R6
4.7K
4.7K
R7
J4
3.5STJK
CH 4
AVCC16AVCC
9
1U
LINE OUTS
C10
100
1
U1A
2
3
17
SD2MUTE
VCC
47U
P2A
2
J2B
C27
.1uF
C26
.1uF
C25
.1uF
C24
.1uF
VCC VCC VCC VCC
1
10
PVCCL
PVCCR
TPA3122D2N
3
R26
10K
Q3
2N3904
VCC
MUTE
MONO INPUT
R16
1K
J3A
RCAX4 PC
231
4
+B
P100K X2
P2B
P100K X2
1 3
5
10K
10K
R3
R4
564
RCAX4 PC
CH 3
R25
1K
220K
C15
10U
R24
P3A
P100K X2
P3B
P100K X2
1 3
4 6
R19
10K
564
J5B
RCAX4 PC
4 6
2
5
R20
10K
R18
10K
R17
10K
CH2