Hafler JF2000 Owner's Manual
TABLE OF CONTENTS
Introduction
.....................................................
Page
1
Features ..........................................................
Page
1
Installation and Setup..
....................................
Page 2
Special System Configurations
.......................
Page 4
Rear Panel ......................................................
Page8
Operation ........................................................
Page 9
LED Displays ...................................................
Page 9
Care ................................................................
Page
10
Troubleshooting
..............................................
Page
10
Specifications
..................................................
Page
12
Warranty
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page 13
INTRODUCTION
The JF2000 is the first amplifier in the signature series line
of Hafler audio components. In the Hafler tradition, it is hand-
made in America. The signature series embodies Hafler's
philosophy of supplying the same quality music reproduc-
tion of higher priced audio components for less.
FEATURES
Output Section
High Current
Capability
Wide Load
Range
SOA Protection
(Safe
Operating
Area)
Thermal
Protection
The
JF2000
uses 32 MOSFET output devices - 16 per
channel - to source the high current and power required.
Each device is rated at 4.0 Amperes continuous drain
current at 100 degrees Celsius.
Each channel can safely produce peak transient output
currents exceeding 50 Amperes. This ensures that mo-
mentary speaker impedance dips and surge current requirements are easily supplied.
The JF2000 is fully rated for loads of 4 and 8 Ohms. It is
stable to 2 Ohms. (This means it will operate safely, cleanly
and stably into 2 Ohms, but very high power dissipation may
lead to frequent thermal shutdown.)
The 16 output devices per channel assure operation well
within the MOSFET Safe Operating Area with low imped-
ances and/or reactive loads.
The output devices of the JF2000 are protected by a so-
phisticated analog computing system. The device instantaneous temperature is continuously calculated by the com-
puter and compared to a maximum limit. If the limit is
reached, the computer cuts back thte power and lights the
channel’s distortion (red) front panel LED.
A pair of thermistors, one mounted on each heatsink, measure temperature of the output system. They control fan
speed and provide thermal shutdown in case temperatures
become too high for safe operation. (Thermal shutdown
turns the power lamp red.)
Toroidal
Transformer
Energy Storage
Great Flexibility
Display
Fan Cooling
The fan cooling system is a key to the
JF2000’s
perfor-
mance. The fan is of a very quiet design, with continuous
variable speed control. When the amp is cool, the fan is
off
As the amp is driven harder, the fan gradually turns on and
speeds up only to the extent needed to sustain the power
dissipation needed for the conditions.
The power supply for the JF2000 is based on a 1000 Volt-
Ampere toroidal (donut-shaped) line transformer. We use
the toroid core (which is more expensive than a conventional
square transformer) for its higher efficiency, lower weight,
smaller size, and freedom from stray magnetic fields. The
1000 Volt-Ampere rating indicates that the transformer can
supply power to a load of 1000 Watts continuously.
Energy storage for the power supply consists of two 42,000
Microfarad capacitors. This large energy storage capability
provides a low-impedance source of extremely high current
for surges, musical transients, variations in speaker impedance, and very low frequencies.
Individual channel gain controls match the JF2000 to a wide
range of installations.
Four Output Modes are available to fit almost any require-
ment: Normal Stereo, Stereo plus Bridged Mono, Bridged
Mono, and Dual Mono.
Simple three-LED multicolor display shows amplifier status
including power, signal level, distortion, and thermal condi-
tion.
INSTALLATION AND SETUP
Amplifier
Placement
The JF2000 is designed to be placed on a shelf or other
substantial support. (A rack-mount front panel is available.)
Take care to ensure unimpeded airflow behind the amplifier,
as the intake and exhaust vents are located at the rear. If the
amp is to be placed in an enclosed wall unit or cabinet, it
would be a good idea to allow for fresh air intake and hot air
exhaust venting in the back of the cabinet, especially for
continuous high-output operation.
2
Power
Connection
Speaker
Connection
Normal Stereo
Connections
The
JF2000 is designed to operate on 120 Volts AC, 60 Hertz
standard U.S. line output) only. Connection is via a standard
3-prong grounded AC plug. If a
3-prong (grounded) outlet is
rot available, the third (ground) wire MUST be grounded to
a
satisfactory electrical ground using adapters available at
nost hardware stores.
If an extension cord must be used, it will rob power from the
amplifier. Use only the highest qualtiy 3-wire (grounded)
extension
cords, with large wire
(14-Gauge
or larger) to
educe
losses.
Speaker
connectors are heavy-duty
gold-plated “5-way”
binding posts, spaced for standard banana jack connectors.
They will accept bare stranded wire up to approximately
12-
Gauge. Banana connectors may be more convenient.
For
normal stereo operation leave ALL REAR PANEL
SWITCHES IN. The amplifier’s left channel red binding post
connects to the left positive (+) speaker terminal and the left
black
post goes to the left negative (-) speaker terminal. Wire
the right channel the same. (Refer to Figure 1)
Figure 1
Left
positive (+) terminal (red) to Left Speaker positive (+)
Left
negative (-) terminal (black) to Left Speaker negative (-)
Right
positive (+) terminal (red) to Right Speaker positive (+)
Right
negative (-) terminal
(black) to Right Speaker negative (-)
3
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