Rolls MX28 owner manual SCHEMATIC

Thank you for your purchase of the MX28 MiniMix VI. The MX28 is a three
channel true stereo mixer designed for keyboard or other stereo line level
signal mixing.
INSPECTION
1. Unpack and inspect the MX28 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 complete the Warranty Registration Card and return it to the
factory.
DESCRIPTION
FRONT PANEL
LEVEL 1 - 3: Volume Controls:
Adjusts the amount of input signal
to the indicated channel.
MASTER LEVEL: Master volume
control, adjusts the amount of
overall signal sent to the Main Right
and Left outputs.
HEADPHONE LEVEL: Adjusts the
amount of signal sent to the Head-
phone Output.
PAN 1 - 3: varies the relative amount of right and left signal from the
channel to the mix bus.
PHONE OUTS: Two 1/4" TRS Stereo jacks for connection to stereo
headphones.
REAR PANEL
CH 1 - Ch 3 INPUTS: 1/4" unbal-
anced inputs
The Right input is the MONO input.
Right and Left MAIN OUTPUTS: 2:
1/4" unbalanced outputs containing
the three mixed stereo signals.
DC IN: Power jack - accepts +12 to
+16 volts DC (outside of the barrel
is positive).
OPERATION
Shown below is an example setup for the MX28. The power adapter is not
shown. It should be conected to the proper voltage, grounded AC outlet.
SCHEMATIC
MX28
LEVEL
1
BAL
LEVEL
2
BAL
LEVEL
3
BAL
MASTER
LEVEL HEADPHONE LEVEL
L
R1L
R2L R3L R
OUTPUT
DC IN
12 - 16
VDC
+
-
122-Apr-1999
Document Number:
Date: Sheet of 1
Ba
M X28 T HR EE CH AN NE L S TE REO M IXE R
M X 28 . S C H A
BA L
M O N O /R IG H T
LE F T
VCC VCC
PO W E R
VCC
CH AN NE L 1 O F 3
VB
VB
VB
VB
VB
VB
VB
VCC
VCC
VCC
VCC
M O N O /R IG H T
LE F T
VCC
VB
VB
VB
M O N O /R IG H T
LE F T
VCC
VB
VB
VB
RI G H T
LE F T
4 6
5
P1 B
P1 00 K X 2
1 3
2
P1 A
P1 00 K X 2
6
57
8
U1 B
45 6 0
2
31
4
U1 A
45 6 0
6
57
8
U2 B
45 6 0
2
31
4
U2 A
45 6 0
6
57
8
U3 B
45 6 0
2
31
4
U3 A
45 6 0
6
57
8
U4 B
45 6 0
2
31
4
U4 A
45 6 0
6
5
7
8
U5 B
45 6 0
3
2
1
4
U5 A
45 6 0
Q5
2N 3 9 0 4
J1
PH ON E 1/4
J2
PH ON E 1/4
J3
PH ON E 1/4
J5
PH ON E 1/4
J6
PH ON E 1/4
J7
PH ON E 1/4
J1 1
PH ON E 1/4
J1 0
J8
PH ON E 1/4
J9
PH ON E 1/4
4 6
5
P2 B
P1 00 K X 2
1 3
2
P2 A
P1 00 K X 2
4 6
5
P3 B
P1 00 K X 2
1 3
2
P3 A
P1 00 K X 2
P7
P1 0 0 K
P8
P1 0 0 K
P9
P1 0 0 K
1 3
2
P4 A
P1 00 K X 2
4 6
5
P4 B
P1 00 K X 2
1 3
2
P1 00 K X 2
4 6
5
P1 00 K X 2
C2
1U
C4
1U
C5
1U
C7
1U
C8
1U
C1 0
1U
C1 1
1U
C1 3
1U
C1 4
1U
C1 6
1U
C1 7
1U
R1
10 K
R2
4. 7 K
R4 R5
10 K
R7
4. 7 K
R8
47 K
R9 R1 0
10 K
R6
10 K
R1 1
10 K
R1 2
4. 7 K R1 3
47 K
R1 4
10 K
R1 5
10 K
R1 6
10 K
R1 7
4. 7 K
R1 8
47 K
R1 9
10 K
R2 0
10 K
R2 1
10 K
R2 2
4. 7 K R2 3
47 K
R2 4
10 K
R2 5
10 K
R2 6
10 K
R2 7
4. 7 K
R2 8
47 K
R2 9
10 K
R3 0
10 K
R3 1
1K
R3 2
10 0
R3 3
10 0 K
R3 4
1K
R3 5
10 0 R3 6
R3 8
30
R3 9
10
R4 1
30
R4 2
10
R4 3
18 K
C2 7
50 3
R4 4
22 K R4 5
2K
2
3
1
J4
JA P DC
D2 L D S G
D1
1N 4 0 0 1
C1
1U
C2 1
12 0 P F
C2 3
12 0 P F
Q1
M P S A 06
Q3
Q4
2N 2 9 0 7
C2 6
47 U
C2 4
47 U
C1 9
10 U
C2 0
10 U
C6
12 0 P F
C1 2
12 0 P F
C1 8
12 0 P F
C1 5
12 0 P F
C9
12 0 P F
C3
12 0 P F
C2 5
1K U F
Q2
2N 2 9 0 7
C2 2
47 U
R3
47 K
R4 0
1K
R3 7
1K
10 K
10 K
BA L
BA L
PH ON E 1/4 "
10 0 K
P6 A
P6 B
M P S A 06
R OL LS C OR P OR AT IO N
51 43 S ou th Ma in St ree t
S alt La ke Ci ty, UT 8 41 07
Re v
Title
Si z e
(MIDI Signal)
To mixer or
recording device
R
L
1
R
L
2
R
L
3
R
L
OUTPUT
DC IN
12 - 16
VDC
+
-
MX28
STEREO
MINI-MIX VI
LEVEL
1
BAL
LEVEL
2
BAL
LEVEL
3
BAL MASTER
LEVEL HEADPHONE LEVEL
Synth Module
Synth Module