JBL L8400P (serv.man12) Service Manual ▷ View online
Studio L Series
L8400P
Amplifier/Subwoofer
SERVICE MANUAL
JBL Consumer Products
250 Crossways Park Dr.
Woodbury, New York 11797
Rev
1 3/2006
- CONTENTS -
BASIC SPECIFICATIONS…………………………………………..1
PACKAGING…………………………….……………….………….2
DETAILED SPECIFICATIONS…………………………………….3
CONNECTIONS..………………………………………………….. 5
OPERATION ………….…………………………..….….………….7
BASIC TROUBLESHOOTING…………………………………….8
EXPLODED VIEW……………………………………………….…9
120V BLOCK DIAGRAM..……………………………………..….10
PCB DRAWINGS………………..………………………………...11
120V ELECTRICAL PARTS LIST …………….…….…………..15
INTEGRATED CIRCUIT/TRANSISTOR PINOUTS………....19
120V SCHEMATICS.……….………………………..…. ………20
L8400P BASIC SPECIFICATIONS
Amplifier Power (RMS)
600 Watts
Peak Dynamic Power *
1200 Watts
Frequency Response (–3dB)
22Hz – Low-pass crossover frequency
Low-Pass Crossover Frequencies
50Hz – 150Hz, Continuously adjustable
Low-Frequency Transducer
12" (300mm) PolyPlas™ cone
Baffle
Low diffraction, IsoPower™
Enclosure
Sealed
Inputs
Gold-plated 5-way binding-post speaker-level;
Left and right line-level, switchable to LFE
Outputs
150Hz when using speaker-level connection
Gold-plated 5-way binding-posts
Dimensions (H x W x D)
16-1/2" (15-1/2" without feet) x 15-1/2" x 15-1/2"
(419mm [394mm without feet] x 394mm x 394mm)
Weight
58 lb (26.4kg)
* The Peak Dynamic Power is measured by recording the highest peak-to-center voltage produced by the power
amplifier with its limiters disabled, across the output of a resistive load equal to minimum impedance of the
transducer, using a 50Hz sine waveburst, 3 cycles on, 17 cycles off.
Occasional refinements may be made to existing products without notice but will always meet or exceed original
specifications unless otherwise stated
amplifier with its limiters disabled, across the output of a resistive load equal to minimum impedance of the
transducer, using a 50Hz sine waveburst, 3 cycles on, 17 cycles off.
Occasional refinements may be made to existing products without notice but will always meet or exceed original
specifications unless otherwise stated
L
8400P
L
series
1
ITEM
NO.
NO.
DESCRIPTION
QTY.
PART NO.
1. Owner’s Manual
1
354038-001
2. Front Grille
1
353234-001
3. Warranty Card, JBL 5YR/1YR
1
338381-001
4. Kit, Spike Foot
4
354432-001
5. L8400P Outer Carton, Black
1
353588-001
L8400P Outer Carton, Beech
1
353588-002
L8400P Outer Carton, Cherry
1
353588-003
ITEM
NO.
NO.
DESCRIPTION
QTY.
PART NO.
6. Pad, Foam, Top, Bottom L8400P
2
353592-001
7. Y-Adapter Cable
1
354058-001
8. Foot, Bump-On 3M, SJ5744
4
330104-001
L8400P
Packaging
5
6
6
1
3
4
7
8
2
2
L8400P Powered Sub/ Plate Amp
LINE VOLTAGE
Yes/No
Hi/Lo Line
Nom.
Unit
Notes
US 120VAC/60Hz
Yes
108-132
120
Vrms
Normal Operation
EU 230VAC/50-60Hz
Yes
207-264
230
Vrms
Normal operation, MOMS required
Parameter
Spec.
Unit
QA Test
Limits
Conditions
Notes
Amp Section
Type (Class AB, D, other)
D
n/a
n/a
Bridge type amplifier, None of the speaker
terminals must be connected to system
GND at any time.
terminals must be connected to system
GND at any time.
Load Impedance (speaker)
4
Ohms
n/a
Nominal
Rated Output Power
450
Watts
380
1 input driven
Measuring 425 Watts Cold
THD @ Rated Power
0.5
%
1
22K filter
THD @ 1 Watt
0.1
%
0.2
22K filter
Dynamic Power
460
Watts
450
Power is the average measurement
of the first four consecutive peaks
of the burst signal
of the first four consecutive peaks
of the burst signal
3/20 Cycles @ 50 Hz, burst test into 4
Ohms, input driven 6dB above its maximum
sensitivity, volume level at Maximum.
Ohms, input driven 6dB above its maximum
sensitivity, volume level at Maximum.
DC Offset
80
mV-DC
100
@ Speaker Outputs
Damping factor
>20
DF
15
Measured at amplifier board
Measured at the speaker cable. 200 Watts,
measured at speaker output terminals
located at the amp board.
measured at speaker output terminals
located at the amp board.
Input Sensitivity
Input Frequency
Input Frequency
50
Hz
30
Nominal Freq.
Left or Right inputs
16.6
mVrms
±2dB
To 1 Watt
Single input driven, Ap Zo=600 Ohms, LP
ON, Volume ctrl & crossover at max
ON, Volume ctrl & crossover at max
Left & Right with LFE or LP
filter OFF Mode selected
filter OFF Mode selected
16.6
mVrms
±2dB
To 1 Watt
Single input driven , Ap Zo=600 Ohms, LP
OFF, Volume ctrl & crossover at max
OFF, Volume ctrl & crossover at max
Speaker/Hi Level Input
165
mVrms
±2dB
To 1 Watt
Single input driven, Ap Zo=25 Ohms,
Normal, Volume ctrl & crossover at max
Normal, Volume ctrl & crossover at max
Signal to Noise
SNR-A-Weighted
100
dBA
90
Relative to rated power (400 Watts) A-Weighting filter
SNR-unweighted
95
dBr
85
Relative to rated power (400 Watts) 22K filter
SNR rel. 1W-unweighted
70
dBr
65
Relative to 1W Output
22K filter
Residual Noise Floor
0.5
mVrms
1
Volume @max, using RMS reading
DMM/VOM (or A/P)
DMM/VOM (or A/P)
Residual Noise Floor
0.5
mVrms(max)
1
Volume @max, w/ A/P Swept
Bandpass Measurement (Line
freq.+ harmonics)
Bandpass Measurement (Line
freq.+ harmonics)
Speaker input rejection
1.0V + RMS applied to + & - inputs
CMRR Speaker in
>37
dB
Reference
50 Hz, Generator GND to system
GND
GND
Input Impedance
Line Input (L, R,LFE)
10K
ohms
n/a
Nominal
Speaker/Hi Level Input
10K
ohms
n/a
Nominal
Filters
LP 4th order variable
LP 4th order variable
50-150
Hz
± 10
Subsonic filter (HPF) 3rd Orde
Fixed
Hz
± 10
Low pass filter OFF
Fixed
Hz
± 20
L or R input driven, LP Filter OFF
HP Speaker output 4 Ohms
200
Hz
± 10
Speaker output loaded with 4 Ohms
HP Speaker output 8 Ohms
100
Hz
± 10
Speaker output loaded with 8 Ohms
Limiter
THD at Max. Output Power
THD at Max. Output Power
YES
n/a
functional
Features
--
Auto - On -Off
YES
--
functional
No switch to select the ATO mode is
provided, Refer to ATO section
provided, Refer to ATO section
L
8400P
L
series
3
