Rolls MA254 Instruction Manual

MA254
5 + 5 watt
Mixer/Amplifier
Connection guide
Salt Lake City, Utah
04/10
• RCA Inputs for all channels, and Channel 4 -
3.5mm stereo input on the front panel.
• Volume controls for each Channel
• Low noise, efficient operation
• Small compact size
• Class D high efficiency amp
The MA254 is a very compact 5 + 5 watt high efficiency amp with
a four channel stereo mixer built in. Left and Right stereo speaker
outputs. The unit is perfect for small speakers in small environ-
ments. Great for in ceiling and projector applications where small
size is needed along with class D low radiated heat locations.
WARNING:
WARNING:
THE MINIMUM SPEAKER IMPEDANCE IS 4
OHMS EACH.
IF YOU CONNECT AND USE THE MA254 WITH A LOW-
ER SPEAKER IMPEDANCE THAN LISTED ABOVE
YOU WILL DAMAGE THE UNIT AND POSSIBLY OTHER
EQUIPMENT THAT IS CONNECTED TO THE MA254.
CH 4 CH 1
CH 2
CH 3CH 4
LEVEL LEVEL LEVEL LEVEL
PS12
CLASS AMP
5 + 5 WATT MIX/AMP
LEFT RIGHT
MA251
3.5mm
STEREO
+
+
-
-
BOTHOUTPUTS MUST BE USED
PHANTOM
CH 1
INPUT
CH 2
INPUT
CH 3
INPUT
POWER
LINE
OUT
ON- OFF
CH 2
MONO
INPUT
MUTE RRR
LLL
CH 4 CH 1
CH 2
CH 3CH 4
LEVEL LEVEL LEVEL LEVEL
PS12
LEFT
RIGHT
MA254
INPUT
+
+
SPEAKER OUTPUTS
LINE
OUT
CH 2
MONO
INPUT
MUTE
MADE IN USA
010010 010010
www.rolls.com
--
AMPMIX
5 + 5 WATT MIX/AMP
CH 1
INPUT CH 2
INPUT CH 3
INPUT CH4
INPUT
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
Efficiency: 85%
Input Sensitivity: 28 mV
Bandwidth: 20Hz - 25 kHz +/- 3dB
+Size: 6.75" x 3.5" x 1.5"
Weight: 1 lb.
75889 02540
68

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.
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.
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.
DESCRIPTION
NOTE: THIS MANUAL ASSUMES THE USER HAS A WORKING KNOWL-
EDGE OF AUDIO ELECTRONICS, BALANCED AND UNBALANCED CON-
NECTIONS, 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 War-
ranty Here button.
CH 4 CH 1
CH 2
CH 3CH 4
LEVEL LEVEL LEVEL LEVEL
MA254
INPUT
MADE IN USA
010010 010010
www.rolls.com
AMPMIX
5 + 5 WATT MIX/AMP
CH 4 CH 1
CH 2
CH 3CH 4
LEVEL LEVEL LEVEL LEVEL
PS12
CLASS AMP
5 + 5 WATT MIX/AMP
LEFT RIGHT
MA251
3.5mm
STEREO
+
+
-
-
BOTHOUTPUTS MUST BE USED
PHANTOM
CH 1
INPUT
CH 2
INPUT
CH 3
INPUT
POWER
LINE
OUT
ON- OFF
CH 2
MONO
INPUT
MUTE RRR
LLL
PS12
LEFT
RIGHT +
+
SPEAKER OUTPUTS
LINE
OUT
CH 2
MONO
INPUT
MUTE --
CH 1
INPUT CH 2
INPUT CH 3
INPUT CH4
INPUT
INTRODUCTION
Thank you for your purchase of the MA254. The MA254 is a four channel mixer/
amplifier 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.
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 WITHAMONO
INPUTAS WELLAS A STEREO INPUT, CHANNEL 2AT CERTAIN IMPED-
ANCES ON THE STEREO INPUT YOU MAY EXPERIENCE CROSS TALK BE-
TWEEN THE LEFTAND 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 amplification device.
MUTE
+B
+B
+B
MONO INPUT
LINE OUTS
VCC
V+
CH 4
CH 3
CH2
IN 12-24 VAC/VDC
2 3 1
J1 JAPDC
C3 1U
R9 100K
R6
4.7K
C7 1U
R26 10K
R24
1K
R14
10K
R15
10K
R19
10K
R20
10K
R12 100K
R2 10K
C6
47U
D2
1N4001
R5
22K C14
47U
C13
2200
R10
100
R8 18K
2 31
4
U1A
4560
6 57
8
U1B
4560
R1 10K
C8 120PF
C4 120PF
C10 47U
R7
4.7K R13
100
1 3
2P1A
P100K X2
1 3
2P3A
P100K X2
1 3
2P2A
P100K X2
4 6
5P3B
P100K X2
4 6
5P2B
P100K X2
4 6
5P1B
P100K X2
+ - - +
STEREO
R3 10K
R4 10K
R21 4.7K D1
LDRR
PVCCL 1
SD
2
MUTE
3
LIN
4RIN 5
BYPASS
6
AGND
7AGND 8
VCLAMP
9
PVCCR 10
PGNDR 11
ROUT 12
BSR 13
GAIN1
14
GAIN0
15
AVCC 16 AVCC 17
BSL 18
LOUT 19
PGNDL 20
U2
TPA3122D2N
C20 1K
C23
1K
C24 .1uF C25
.1uF
C26 .1uF C27
.1uF
C21 .22uF C18 .22uF
L1 47uH L2 47uH
R27 4.7K R28 4.7K
C19 .47uF C22 .47uF
VCC VCC VCC VCC
SPEAKER OUT
VCC
1
Rolls Corporation
5968 S 350 W Murray Utah84107
1
MA254.SCH A
5 APRIL 2010
Title Size: Document Number:
Date:
Rev:
Sheet of
MA254 MIXER AMPLIFIER
Rb
VCC
R25
220K
Q3 2N3904
C15 10U
C16
1U
C17 1U
D3
1N4001
D5
1N4001
D4
1N4001 C12
2200
C11
2200
1 2 3 4
J6 PUSH TERMINAL
R16 1K
R18 10K
R17 10K
J4
3.5STJK
C5
.047
C9 .047
R32
100K
R31 100K
CH 1
2
3
1
J5A RCAX4 PC
5
6
4
J5B RCAX4 PC
5
6
4
J2B
RCAX4 PC
5
6
4
J3B RCAX4 PC
2
3
1
J2A RCAX4 PC
2
3
1
J3A RCAX4 PC
1 3
2P4A
P100K X2
4 6
5P4B
P100K X2
SCHEMATIC