Harman JBL EON10-G2 Operating manual

Technical Service Manual
Rev. A
7/26/2004

TABLE OF CONTENTS
PRODUCT OVERVIEW 3
SPECIFICATIONS/FREQUENCY RESPONSE GRAPHIC 4
PANEL CONTROLS, CONNECTORS AND INDICATORS 5
BLOCK DIAGRAM 7
CIRCUIT DESCRIPTIONS 8
TROUBLESHOOTING GUIDE 19
SEMICONDUCTOR DIAGRAMS 21
FINAL TEST PROCEDURE 22
PICTORIALS OF PCB ASSEMBLIES 23
JBL WARRANTY LIMITED WARRANTY 27 - 52
SYSTEM EXPLODED VIEW
FAILURE QA CODES
SCHEMATICS / MASTER PARTS LIST

Product Overview
The new EON10 G2 compact powered speaker features a 10" woofer, increased power and a
three input mini-mixer. The EON10 G2 is ideal for AV applications, smaller musical and spoken
word performances and, when combined with the new EONSUB G2 powered subwoofer,
provides a full range sound system for small and medium sized events.
The first generation EON10 was very popular, not only with musicians, but with hotels,
meeting planners, AV companies and just about any application where portable compact sound
reinforcement was needed. Its successor, EON10 G2 offers more power, more flexibility and a
refined appearance that will make it even more appropriate for its many types of users.
The EON10 G2 has more power than the first generation EON10, with 125 watts for low
frequencies and 50 watts for the highs. The 10" Differential Drive low frequency driver uses a
neodymium magnet for light weight and reduced distortion. The one-inch JBL 2412
compression driver for the high frequencies includes a titanium diaphragm and ferro-fluid
cooling.
The EON10 G2 shares the same appearance improvements with its larger companion EON15 G2,
including new black exterior material and a mini-mixer with three inputs. An additional XLR output
allows EON Speakers to be daisy-chained together. As with other EON G2 speakers, the EON10
G2 is kept cool, not by heatsinks or fans, but by JBL's Thermomaster Total Thermal Management
System.
With its versatile cabinet design, the EON10 G2 can be used in several different ways. As a front of
house speaker, the EON10 G2 can sit on a flat horizontal surface or be raised in the air using
standard tripod speaker stands.
The cabinet has also been designed to let the EON10 G2 be snugly placed atop the EONSUB G2
for added volume and extended bandwidth. In addition, the angled back of the speaker allows
its use as a vocal or instrument monitor on stage.

Specifications
Frequency Response
Notes:
JBL Professional is continually engaged in research activities to enable further product improvement. New materials, production methods and design
refinements are instituted into the existing product without notification and, therefore, the information contained within this manual is subject to
change without notice. Rest assured that your JBL Professional equipment will always equal or exceed the published design specifications unless
otherwise stated.

Connectors

Indicators

Block Diagram

AC Input PCB
The line voltage of 117 Vac is connected at input jack P1 on the ac input PCB. Shunting
capacitor C1 reduces the probability of electronic damage that could occur should any
abnormalities exist on the input voltage. Capacitors C2 and C3 work in conjunction with
C1 to help stabilize this input voltage and reduce the instantaneous line voltage spikes that
could cause noise especially in the high frequency range. Pin 2, the neutral, is connected to
ground. Both lines of input voltage are directly connected to the 2-pole 2-position power
switch.
The operational idle current will be below the rated 2.5 amp fuses to protect the user from
fire. If the amplifier is consistently overdriven or an abnormality does exist with the
equipment, the fuses will open and current will cease to flow. After the fuses, the voltage
travels to the manually operated voltage selection switch. It is important to power down the
equipment when this switch is used to avoid possible driver damage. The switch,
essentially, determines which transformer primary is utilized. We will assume that the input
voltage is 115 Vac for this circuit description. The toroidal transformer output would then
deliver 44Vac to the power supply connector P2 on the main amplifier PCB.

Power Supply
This is the power supply circuit of the EON 10-G2. Operational voltages, necessary of the
main amplifier and processing circuits, are created on this PCB. The schematic, shown
above, contains three individual circuits: the signal shutdown, the main rectification and low
voltage power supply circuits.
Note: Voltages documented minimally differed from published results and are
attributable to component tolerance variations.
Voltage rectification by BR1 modifies the 44Vac delivered by the toroidal power
transformer at P2 into the positive and negative 29 volts. This voltage feeds the main
amplifiers and the positive and negative 15 volt power supplies used for signal processing.
C63 and C62 filter this rectified voltage, respectively.
In the second circuit, Zener diodes D5 and D6 clamp the positive and negative 29 Vdc so
that voltage regulators Q3 and Q4 output positive and negative 15 Vdc. Further filtering of
this voltage occurs by C61 and C58. An LED, D51, is serially connected with R47 to
negative 15 Vdc and functions as the pilot lamp.
The third circuit, the signal shutdown circuit, monitors several different parameters: the
presence of ac voltage, the presence of the low voltage supplies and the output transistor
temperature. Absence of any voltage or excessive temperature detected will cause
comparator U4 to trigger Q1 resulting in muting of the audio output. The time constant of
C22/R15 provides the initial speaker delay time upon power up.

Signal Input Circuitry
The above is the XLR line input circuitry for the EON 10-G2. The balanced signal from
pins 2,3 of J2 is attenuated by R40 and R39. Signal overload is contained by the signal-
limiting diodes, D4 and D1, preventing possible internal IC damage by clamping them to the
±15 Vdc supplies. This will provide a maximum of 30 volts of signal voltage swing
between the inputs of isolation IC U4A. The output signal of this IC, pin 1, is passed
through connectors RC1, and PA2 to the volume control PCB. Coupling capacitors C28,
C29, and C30 prevent dc circuit interaction but allow signal throughput to VR2 and VR3.
Once the signal is returned to the input PCB at pin 3 of RC1, it enters the switchable-
gain/sensitivity IC U4B at pin 5. When the mic/line switch, SW2, is toggled from mic to
line input, resistors, R25/R17, are serially added to R31/R6, which increases the input
impedance at J2 input thereby decreasing the signal delivered to U4A. This action corrects
the level for proper signal amplification. The opposite occurs when SW2 is toggled in the
reverse direction. Output of U4B on pin 7 enters pin 6 of summing IC U5 via R51 and C37.
The output of this IC feeds the Loop/mix circuitry IC