JBL Ms 8 Service Manual

							
 
      
MS-8 
 
8 Channel 
 
System integration digital processor 
 
 
SERVICE MANUAL 
 
 
 
 
 
JBL Consumer Products 
8500 Balboa Blvd. 
      Northridge, CA.  91329                  Rev0   5/2010 
Released 2010 
Discontinued XXXX  
						

							
 
 
-  CONTENTS  - 
 
SPECIFICATIONS ………………………………………\
..1 
PACKAGING……………..………………………….\
.…....2  NOTICE REGARDING TESTING THE UNIT…….….…3 
CONNECTIONS ……………………………..…………\
…4 
RESETTING THE MICROPROCESSOR………..…….15 
REMOTE CONTROL …………….….…………..………1\
6 
TROUBLESHOOTING……………..…..…………………17  EXPLODED VIEW/PARTS LIST……...….….………….22 
AMPLIFIER BLOCK DIAGRAM…….……………..….…23  ELECTRICAL PARTS LIST ..….…….……….…………26 
P.C.B. DRAWINGS….……………………………….……30 
IC/TRANSISTOR PINOUTS..…………….……….….…..37  SCHEMATICS……………...……………….………..…...93 
 
MS-8 Specifications 
 
Power Output:           20W x 8 channels @ 4 ohms 
Maximum Output Power:         30W x 8 channels @ 2 ohms 
Frequency Response:     20Hz–20kHz 
Signal-to-Noise Ratio (Line Input to Line Output):   >90dB 
Signal-to-Noise Ratio (Line Input to Spkr Output):   >85dB 
Maximum Input Voltage (Speaker-Level Input):   15V 
Maximum Input Voltage (Line Input):     2.8V 
Maximum Output Voltage (Line Output):     2.8V 
Maximum Current Draw:     16A 
Standby Current Draw:         
						

							
MS-8 PACKAGING
LITHIUM COIN BATTERY 3VDC  CR2032
 
 MS-8                      
 
 
 
2  
						

							
NOTE: Although some typical connections and 
controls are shown, the JBL
® MS-8 digital 
processor includes many features and digital 
controls not found on conventional car audio 
amplifiers. Also, the calibration, setup and 
usage for the MS-8 is unique. 
 
Details can be found in the MS-8 owner’s 
manual, which can be downloaded here: 
 
http://www.jbl.com/EN-US/Products/Pages/Pr oductDetails.aspx?PID=MS-8&accT=1&tsT=0&ovT=0 
 
(click on link) then on Grey tab SUPPORT
 
 MS-8                      
 
 
 
3  
						

							
www.jbl.com
POWER
IMPORTANT: Perform the power connections in the following order.
1.  Gnd:  Connect this terminal to a paint-free location on the vehicle chassis. 
IMPORTANT: Use at least 12-gauge wire for this connection.
EnglishCONN e CT i ON s
REMOVE
FOR
SOFTWARE UPDA TE
25A 
fuse
Mic 
connection
Line input
connections Hi Level input
Remote out
connection
Speaker outputconnections Line output
connections Aux input
connections Display
connection Power
LED
Reset
button Update
connection
+12V
connection
Remote in
connection GND
connection




Chassis
ground
(unpainted)
5
CONNECTIONS
 
 MS-8                       
 
    
4  
						

							
CONNeCTiONs


To turn-on
terminals of
all system
amplifiers
+
-
1 x 25A
25A fuse within
18" of battery
terminal
Cable from MS-8
+12V terminal
Use a grommet
through the
firewall
3.  Rem Out:  Connect this terminal to the remote turn-on terminals of all amplifiers in the system. The 
    output is +12V DC, 1A.
IMPORTANT:
	The	MS-8	MUST	control	the	turn-on	signal	of	all	the	other	amplifiers	
that follow the MS-8 in the signal path.
If
	your	system	includes	a	factory-installed	outboard	amplifier,	the	turn-on	signal	
may	be	available	at	the	amplifier.	If	your	factory	amplifier	has	a	turn-on	wire,	cut	it	
and connect the head-unit side of the wire to the MS-8’s Rem In terminal and the 
amplifier
	side	of	the	wire	to	the	MS-8’s	Rem	Out	terminal.
This arrangement will allow the factory stereo to turn the MS-8 on whenever the 
stereo
	is	turned	on	and	will	allow	the	MS-8	to	turn	the	factory	amplifier	on	and	off.	
It will also help to eliminate audible clicks and pops when the system turns on and 
off. 2.  +12V:  Connect this terminal to the vehicle battery’s positive (+) terminal. Insert  a 25A fuse in series on 
    the +12V wire no further than 18 inches (46cm) from the battery terminal.
IMPORTANT: Use at least 12-gauge wire for this connection.
6
CONNECTIONS
 
 MS-8                       
 
    
5  
						

							
e CT i ON s
English
Rem In: Connect this terminal to the remote turn-on output of the system’s source unit, if the 
source unit has a remote turn-on output. Alternately, you can connect this terminal to the vehicle’s 
accessory (ACC) power circuit. Any voltage over +4V DC at this terminal will trigger the MS-8 to 
turn on. 
NOTE: See Step 3 for more details about connecting the Rem In terminal to a factory-installed 
stereo system. 
AUDIO INPUTS
Many factory-installed systems include on-board equalization and crossovers that make simple 
connection of aftermarket products difficult. The MS-8 includes the signal-summing circuitry, signal-
conditioning EQ and time-correction processing that are necessary to reconstruct a flat, full-range, 
two-channel signal when you use the MS-8 with factory-installed equipment. 
Aftermarket head units with line outputs provide a flat, full-range, two-channel signal on their front line 
outputs, so you need to connect only those channels to the MS-8.
To head unit
remote turn-on
or vehicle
ACC terminal
7
CONNECTIONS
 
 MS-8                       
 
    
6  
						

							
CONNeCTiONs
Aftermarket head unit
MS-8 main unit Rear
line out
Front
line out
RCA
audio cables Subwoofer
line out
DO NOT USE
Line inputs1 and 2
Connecting an aftermarket head unit
If you’re using the MS-8 with an aftermarket head unit that has RCA-type outputs, connect the head unit’s 
front left and front right outputs to the MS-8’s line inputs 1 and 2 only. Do NOT connect any other head-unit 
output signals to the MS-8’s line inputs 3 – 8. During the calibration/setup process, the MS-8 will “normalize” 
the input signals and derive as many output signals as your speaker system requires.
IMPORTANT:  Do not connect the head unit directly to any amplifiers, including a subwoofer amplifier. The 
MS-8’s signal processing takes nearly 8ms, so any signals connected directly to a head-unit will be ahead 
of the signals leaving the MS-8 by about 8ms. This difference will cause them to be out of sync with the 
signals that pass through the MS-8.  The MS-8 must generate all the signals that are sent to all of the 
system’s speakers!
8
CONNECTIONS
 
 MS-8                       
 
    
7  
						

							
ONNeCTiONsEnglish
Connecting a factory radio/head unit
If you will be connecting the MS-8 to a factory-installed stereo or a factory-installed amplifier (often located in 
the vehicle’s trunk), connect each of your factory front-speaker and subwoofer outputs to one of the MS-8’s Hi 
Level inputs. Be sure to connect the outputs for all speakers that are part of the vehicle’s front left and front right 
speakers.
You can connect the factory front speaker outputs to any MS-8 Hi Level inputs, but factory stereo or amplifier 
subwoofer outputs MUST be connected ONLY to the MS-8’s channel 7 and/or 8 inputs . During the calibration/
setup process, the MS-8 will “normalize” the input signals and derive as many output signals as your speaker 
system requires.
NOTE: The above illustration shows only a general connection example and does not represent any particular 
vehicle audio system.
Insert the included Hi Level input wiring harness into the MS-8’s Hi-Level-input connector until it locks into place.
IMPORTANT:  The MS-8’s Hi Level input wiring harness has gray and white wires. Each channel has a white 
(positive or “+”) wire and a gray (negative or “–”) wire. Each wire is labeled with its channel number and polarity, 
and is pre-stripped for easy connection to your factory radio’s speaker outputs.  Make sure that the ( + ) and 
( – ) wires do not touch each other. Touching wires can cause a short circuit that can damage the 
MS-8 or your head unit.
To ensure proper polarity, connect each factory-radio positive (+) terminal to the respective 
“+” terminal on the MS-8. Connect the negative (–) terminals in a similar way.
+ –
+ –
+ –
+ –
+ – + –
Factory stereo
wiring harness
MS-8 main unit Front right
Front left
Center
Side left Rear left
Side right Rear right
Connect
Ch 4
Ch 3
Ch 2 Ch 7
Ch 1 Ch 8
Ch 6
Ch 5
*NOTE: Subwoofers
MUST be connected 
to MS-8 input 7 
and /or input 8
Connect Subwoofer*
DO NOT USE
9
CONNECTIONS
 
 MS-8                       
 
    
8  
						

							
CONNeCTiONs
Aux 
input
To
headphone
output
Aux input:  If you will be using a portable music player or CD player as an auxiliary audio-source unit, 
connect its line or headphone output to the MS-8's Aux input using a cable that terminates in stereo 
RCA audio connections. You can switch between the MS-8's Head Unit inputs and Aux input in the 
MS-8's Input Selection menu. See  Main Menu, on page 35.
10
CONNECTIONS
 
 MS-8                       
 
    
9