Hafler 0915P User manual

Haflee
HOME AUDIO COMPONENTS
Series 0915
P R E A M P L I F
I E R

NOTICE - IMPORTANT SAFETY INFORMATION
RISK OF ELECTRIC SHOCK
00 NOT OPEN
WARNING: TO PREVENT FIRE OR
SHOCK HAZARD, DO NOT EXPOSE THIS
EQUIPMENT TO RAIN OR MOISTURE.
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The lightning flash with arrowhead symbol within
an equilateral triangle is intended to alert the
user to the presence of uninsulated “dangerous
voltage” within the product’s enclosure, that may
be of sufficient magnitude to constitute a risk of
electric shock to persons.
The exclamation point within an equilateral
triangle is intended to alert the user of the
presence of important operating and mainte-
nance (servicing) instructions in the literature
accompanying the appliance.
1.
2.
3.
4.
5.
6.
7.
8.
9.
READ INSTRUCTIONS
All the safety and operating instructions of your Hafler equipment should be read before power is applied to the
equipment.
RETAIN OWNERS MANUAL
These safety and operating instructions should be retained for future reference.
HEED WARNINGS
All warnings on the equipment and in the operating instructions are important and should be followed.
FOLLOW INSTRUCTIONS
All operating and use instructions are important and should be followed.
HEAT
The equipment should be kept away from areas of high temperature, such as heater vents, radiators, stoves/ovens,
fireplaces, etc.
VENTILATION
The equipment should be used in an area suitable for proper ventilation. Care should be taken not to impede airflow
in and around the cabinet. Do not mount on a carpeted shelf or in a sealed enclosure. Allow for proper clearance above
the equipment.
WATER AND MOISTURE
The equipment should not be used in or around water, such as a bathtub, sink, or swimming area. Also, the equipment
should not be used in areas prone to flooding, such as a basement.
POWER SOURCES
The equipment should be connected only to a power source of the same voltage and frequency as that listed on the
rear panel above the power cord entry point.
POWER CORD PROTECTION
Power cords should be arranged so that they do not interfere with the movement of objects in the room: people, fan
blades, utility carts, etc. Also, care should be taken that the cord is not pinched or cut, and placed so that it is not in
danger of being pinched or cut, as in under a rug, around a tight corner, etc.
10. POWER CORD GROUNDING
The power supply cord is of a three wire grounded type, designed to reduce the risk of electric shock sustained from
a live cabinet. It is assumed to be of suitable length for most uses of the equipment. The use of extension cords and
power strips is discouraged unless they are of suitable rating to deliver the required total current for safe operation of
all connected equipment. Furthermore, extension cords or power strips must provide the same three wire grounded
connection. It is important that the blades of the equipment’s plug be able to fully insert into the mating receptacle.
Never remove the round grounding pin on the plug in an attempt to mate to a two wire ungrounded receptacle: use
a grounding adaptor with the grounding tab or wire suitably connected to earth ground.
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11. NON-USE PERIODS
During periods of extended non-use, the power cord should be unplugged from the power source.
12. CLEANING
The equipment should be cleaned only as detailed in the operating instructions.
13. OBJECT AND LIQUID ENTRY
Care should be taken so that objects and/or liquids, such as cleaning fluids or beverages, are not spilled into the
enclosure of the equipment.
14. DAMAGE REQUIRING SERVICE
Hafler equipment should be serviced by qualified service personnel when:
A. The power supply cord or plug has been damaged, or
B. Objects have fallen, or liquid has been spilled into the equipment, or
C. The equipment has been exposed to rain, or
D. The equipment does not appear to operate normally or exhibits a marked change in performance, or
E. The equipment has been dropped, or the enclosure has been damaged.
15. SERVICING
The user should not attempt to service the equipment beyond that which is described in the operating instructions. All
other service should be referred to qualified service personnel.
16. CARTS AND STANDS
The equipment should be used with carts or stands only of sufficient strength and stability for the use intended.
An equipment and cart combination should be moved with care. Quick stops and starts, excessive force, and
uneven surfaces may cause the equipment and cart combination to topple.
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TABLE OF CONTENTS
PERFORMANCE SPECIFICATIONS
............................................................................................ 4
General Information ............................................................................................................... 5
INSTALLATION
Rackmounting ........................................................................................................................ 5
Ventilation/Placement ............................................................................................................ 5
Line Voltage ........................................................................................................................... 5
OPERATION/CONNECTIONS
Power Cord Connection ........................................................................................................ 5
Initial Power-Up/Muting System ............................................................................................ 5
Convenience Outlets ............................................................................................................. 6
Line Level Inputs ................................................................................................................... 6
Phono Section ....................................................................................................................... 6
Front Panel View Diagram ..................................................................................................... 7
Rear Panel View Diagram ..................................................................................................... 8
Tape Input/Record Output ..................................................................................................... 9
Tone Controls/Tone Switch ................................................................................................... 9
Volume Control ...................................................................................................................... 9
Balance Control ..................................................................................................................... 9
Out
1,
Out 2, And Output Switch .........................................................................................
10
Headphone Output ..............................................................................................................
10
CIRCUIT DESCRIPTION
Phono Section ......................................................................................................................
10
Line Level
Inpu? Selector System .........................................................................................
10
J-FET
Buffer And Record Output Driver..............................................................................
11
Tape Monitor Switching ........................................................................................................
11
Volume And Balance Controls..............................................................................................
11
Line Amplifier..
.....................................................................................................................
11
Tone Control System ............................................................................................................
11
Muting System .....................................................................................................................
11
Power Supply .......................................................................................................................
11
Headphone Amplifier ........................................................................................................... 12
ADDITIONAL INFORMATION
Installing Phono Option ....................................................................................................... .12
Phono Board Installation Diagram ....................................................................................... .13
Installing Cartridge Loads .................................................................................................... .14
Changing Line Voltage Rating ............................................................................................. .14
Cartridge Loads Installation Diagram .................................................................................. .15
General Troubleshooting Hints ............................................................................................ .16
Ground Loops ...................................................................................................................... .17
Cleaning/Maintenance ......................................................................................................... .17
Functional Block Diagram .................................................................................................... .18
Main Board Parts List .......................................................................................................... .19
Main Board Component Layout Diagram ............................................................................ .20
Main Board Circuit Schematic Diagram ...............................................................................
.21
Phono Board Parts List ........................................................................................................ .22
Phono Board Component Layout Diagram.......................................................................... .23
Phono Board Circuit Schematic Diagram ............................................................................ .24
SERVICE POLICY AND LIMITED WARRANTY .........................................................................
.25
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PERFORMANCE SPECIFICATIONS
PHONO SECTION
(Measured At
REC OUT)
LINE AMPLIFIER
(Measured at
OUT 1 or OUT 2)
HEADPHONE
AMPLIFIER
All specifications are for 20 Hz - 20 kHz unless specified otherwise.
FREQUENCY RESPONSE: +/-0.1
dB
MAXIMUM OUTPUT: 5 volts RMS
TOTAL HARMONIC DISTORTION AND NOISE:
Moving Magnet:
.002%
Moving Coil: .009%
SENSITIVITY (For 0.5 volts RMS at REC OUT, @1 kHz):
Moving Magnet: 6.0 mV RMS
Moving Coil: 600 uV RMS
SIGNAL TO NOISE RATIO (A-weighted, relative to 0.5 V RMS at REC OUT):
Moving Magnet: -87
dB
Moving Coil: -80 dB
MAXIMUM INPUT SIGNAL (@ 1
kHz):
Moving Magnet: 65 mV RMS
Moving Coil: 6.5 mV RMS
INPUT IMPEDANCE:
Nominal: 47,000 ohms
Moving Magnet: 220 pF as supplied, user adjustable
Moving Coil: 100 ohms as supplied, user adjustable
GAIN (@ 1 kHz):
Moving Magnet: +38.5
dB
Moving Coil: +58.5 dB
FREQUENCY RESPONSE: +/- 0.1 dB (into 33,000 ohms)
BANDWIDTH: 8 Hz
- 170 kHz, -3 dB, into 10k ohm load
MAXIMUM OUTPUT: 6 volts RMS
TOTAL HARMONIC DISTORTION AND NOISE:
.008% @ 2 volts RMS
SENSITIVITY (For 0.5 volts RMS Output): 45 mV RMS
SIGNAL TO NOISE RATIO (A-Weighted, relative to 2 volts RMS output): -100
dB
INPUT IMPEDANCE: 20k ohms (including PHONO/AUX1 when phono option not installed)
OUTPUT IMPEDANCE: 316 ohms
TONE CONTROLS> Bass: +/- 16
dB @20 Hz, moving inflection, variable turnover
Treble: +/- 14
dB @ 20 kHz, shelving @5 kHz, fixed turnover
MAXIMUM OUTPUT: 4 volts RMS into 150 ohm load
OUTPUT IMPEDANCE: 150 ohms
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GENERAL j INPUTS: Tuner, Video, CD, Phono/Aux 1, Aux 2, Tape Monitor
INFORMATION
INSTALLATION
OUTPUTS: Out 1, Out 2, Record Out, Headphone
CONTROLS: input Selector, Volume, Tape Monitor , Tone Control In, Balance, Bass, Treble,
Output Off, Power, Phono MM/MC
INDICATORS: Mute/Standby, Power
CONVENIENCE OUTLETS: 1 Unswitched, 4 Switched (Polarized)
(Convenience Outlets are not included on 200-240 VAC units)
PHYSICAL DIMENSIONS:
17” (W) x 7-5/8” (D) x l-3/4” (H) (excluding feet); Faceplate 17” or 19” (W).
43.2cm (W) x 19.4cm (D) x 4.5cm (H) (excluding feet); Faceplate 43.2cm or
483cm (W).
POWER CONSUMPTION (Excluding Convenience Outlets): 9 watts Max.
AC LINE VOLTAGE OPERATING RANGE: (exceeding lower limit will activate muting circuit;
exceeding upper limit will result in overheating and/or component damage)
100
- 120 Volt 50/80 Hz Models: 85 - 130 volts
200
- 240 Volt 50/80 Hz Models: 170 - 280 volts
RACKMOUNTING
VENTllATlON/
PLACEMENT
LINE VOLTAGE
The 915 Preamplifier is supplied in either a 17” Black Version, or a 19” Silver Version. The 19
model has rackmounting holes provided for installation in equipment racks. The holes are on
standard EIA spacings.
The 915 produces very little heat during operation, and therefore requires no special consider-
ations for ventilation. The preamplifier should be located at least several inches away from
components that contain large power transformers (such as power amplifiers), due to the
possibility of audible hum or buzz from magnetic radiation.
The 915 Preamplifier is configurable for either 100
- 120 volt, or 200 - 240 volt operation. This
is accomplished by changing internal jumpers on the printed circuit board. The procedure is
detailed in the section “CHANGING LINE VOLTAGE RATING”. Make sure that the unit is
configured for your local AC line voltage before attempted use. The configuration is labelled
directly above the power cord connector.
OPERATION/CONNECTIONS
POWER CORD
CONNECTION
INITIAL POWER-
UP/MUTING
SYSTEM
Units wired for200-240 VACare supplied without power cords. Local agents will supply cords with
male connectors appropriate to the local standard.
Units wired for 100-120 VAC are supplied with a detachable AC power cord. The female
connector plugs into the receptacle provided on the rear panel. This power cord is a standard
IEC Type 320, 3-wire, 18 gauge assembly. Should replacement ever be necessary, be sure to
replace it with an identical cord.
Never remove the grounding pin from the male end of the cord. In applications where a grounded
wall outlet is not available, a ground adaptor should be employed, with the ground tab or wire of
the adaptor connected to a suitable earth ground.
For units wired for 200-240 VAC, the front panel Power Switch controls the power to the
Preamplifier’s circuitry. If desired, this switch may be left “on” at all times to allow circuits to be
thermally stabilized for maximum fidelity as soon as the system is used.
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CONVENIENCE
Units wired for 200-240 VAC are supplied without convenience outlets to conform to Regulatory
OUTLETS
Safety requirements.
LINE LEVEL
INPUTS
PHONO SECTION
The ground terminal near the MC/MM switch is provided for turntable frame grounding via the extra
(When Installed) ground wire provided on most turntables.
For units wired for 100- 120 VAC, the Power Switch controls the Switched Convenience Outlets only.
As soon as the 915 is plugged into the AC line, power is applied to the circuitry (regardless of the
position of the front panel Power Switch). Therefore, all connections should be performed with the unit
unplugged.
For all units, when power is applied, the Ready Light will glow red for several seconds, indicating that
the Audio and Headphone Outputs are muted. Once the delay period has passed and the power
supply has stabilized, the light will turn green. The preamplifier is now ready to enjoy.
The muting will reactivate immediately (and the Ready Light turn red) upon loss of AC line voltage,
(or operating the Power Switch on 200-240 VAC units), or if line voltage falls below a level which
precludes proper operation of the preamplifier’s circuitry.
Units wired for
700- 720 VAC have a total of five outlets for connection of associated components. The
Unswitched Outlet is powered at all times, which should generally be used for a turntable or tape deck.
The remaining four Switched Outlets are powered when the front panel Power Switch is engaged, as
indicated by the switch’s green pilot light.
The maximum power available from these outlets is 1200 watts total. This total power may be drawn
from a single outlet, or a combination of outlets. Since some power amplifiers consume more than
1200 watts at maximum output, check the power amplifier’s rating before connecting to these
convenience outlets.
The inputs labelled CD, Tuner, Video, Aux 2, and Phono/Aux 1 (when the Phono Option is not
installed), are identical line level inputs. The names chosen for these inputs are for convenience only,
and may be used interchangeably, or for any other type of line level source. These inputs are selected
via the rotary front panel Selector Switch.
The Phono/Aux 1 input is converted from a line level input to a high gain RIAA phono input when the
Phono Option is installed. See Phono Section.
The 915 Preamplifier is available with an optional Phono Amplifier section. This option may be
installed at time of purchase, or at a later date. Inclusion of this option is indicated by the presence
of a switch button protruding from the rear panel opening marked MC/MM. Otherwise, this opening
will be filled by a plastic cover.
The MC/MM switch should be set to MC for low output (typically 0.2
- 0.5 mV) moving coil cartridges,
and set to MM for high output (2
- 5 mV) moving coil cartridges or moving magnet cartridges.
NEVER OPERATE THE MC/MM SWITCH UNLESS THE VOLUME CONTROL IS TURNED FULLY
DOWN. The very high gain present in the Phono Amplifier can result in switching transients capable
of blowing amplifier or speaker fuses, and possibly damaging some loudspeakers.
As supplied from the factory, the phono cartridge input termination is 47,000 ohms in parallel with 220
pF in the Moving Magnet mode, and 100 ohms in the Moving Coil mode. The value of capacitance
and resistance is user selectable via plug-in components. See “Installing Cartridge Loads” for further
information and instructions.
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INPUT SELECTOR BALANCE CONTROL TREBLE CONTROL
VOLUME CONTROL BASS CONTROL
HEADPHONE JACK
POWER SWITCH
UP TO TURN ON
SWITCHED OUTLETS*
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RACKMOUNT HOLES
(19” VERSION ONLY) TAPE MONITOR SWITCH TONE IN SWITCH OUTPUT OFF SWITCH READY LIGHT UP TO MONITOR TAPE INPUT UP TO ACTIVATE BASS & TREBLE UP TO TURN OFF RED FOR MUTE ACTIVATED
OUT1 &OUT2 GREEN FOR OPERATE
915 PREAMPLIFIER FRONT PANEL VIEW
*lOO-120 VAC UNITS ONLY.
200-240 VAC UNITS ARE WITHOUT CONVENIENCE OUTLETS:
POWER SWITCH CONTROLS PREAMPLIFIER POWER.

AC LINE VOLTAGE
RATING
UNSWITCHED
OUTLET*
OUT 2
TAPE
VIDEO CD PHONO CHASSIS
OUT
1
REC OUT
AUX 2
TUNER
PHONO/AUX
1
GROUND
LINE CORD CONNECTOR
SWITCHED OUTLETS OUTPUTS
INPUTS
TOP ROW
-
RIGHT CHANNEL
BOTTOM ROW
-
LEFT CHANNEL
MC/MM SWITCH
(PHONO OPTION ONLY)
IN-MOVING COIL
OUT
-
MOVING MAGNET
915 PREAMPLIFIER REAR PANEL VIEW
*100-l
20 VAC UNITS ONLY.
200-240 VAC UNITS ARE WITHOUT CONVENIENCE OUTLETS.

TAPE INPUT/ The 915 incorporates one monitoring loop for use with tape decks, or other input/output signal
RECORD OUTPUT
processors.
TONE CONTROLS/
TONE SWITCH
VOLUME
CONTROL
BALANCE
CONTROL
The Ret Out jack feeds a signal to a tape recorder’s input. The signal present at this output is
the same as indicated by the Selector Switch. This output may alternately be used to feed the
input of a signal processing device, such as an equalizer.
Though rare, it is possible that some external devices connected to
Rec Out may cause slight
distortion to the main signal path when that device is turned off. This is due to possible
semiconductor junction rectification in unpowered circuits. If this is suspected, leave power
applied to any device connected to
Rec Out during critical listening.
The Tape Input is electrically the same as the other line level inputs, but is selected via the Tape
Monitor Switch. Activating this switch (UP position) breaks the main signal path after the Input
Selector System and allows monitoring of the tape decks output, during recording or playback.
Activating this switch does not affect the signal at the
Rec Out jacks.
The Tape Input may alternately be used for the return signal from a signal processing device, such
as an equalizer. The Tape Input may also be used for an additional line level input, although this
signal cannot be made available to the
Rec Out jacks.
A common system “malfunction” can often be traced to inadvertently leaving the Tape Monitor
Switch engaged: in case of no sound from a selected line level input, check that the Tape Monitor
Switch is de-activated (DOWN position).
See the Functional Block Diagram for a better understanding of the Tape Monitor Signal routing.
The Tone In Switch activates the Bass and Treble Controls when moved to the UP position.
In
the DOWN position, the Tone Controls are completely removed from the signal path, regardless
of Bass and Treble knob position.
The Bass Control has a variable inflection, or “hinge” point so that only the very low frequencies
are affected by small amounts of knob rotation on either side of center. This facilitates small
amounts of low frequency corrections without noticeably altering the musical balance at upper
bass frequencies. As the knob rotation is increased further from center, frequencies closer to 500
Hz are affected.
The Treble Control has a fixed “hinge” point at 1
kHz and has a “shelving” action above 5 kHz.
This affords proper high frequency corrections without irritation from excessive boost at extreme
high frequencies.
Activating the Tone Control Switch may cause a slight change in tonal balance even when both
Bass and Treble controls are in their center detented position, and therefore the Tone System
should be disabled via the switch when no tone control action is desired. The tone controls also
limit the total bandpass of the line amplifier.
This precision detented potentiometer increases output level in approximately 1 dB steps
clockwise from the 12 o’clock position. Counterclockwise from the 12 o’clock position, each step
is progressively greater until full attenuation is achieved at maximum counterclockwise position.
This arrangement allows the most natural and useful volume control action for a wide variety of
listening levels.
This control alters the proportion between right and left output volumes. In the full counterclockwise
position, only the left channel will be heard. In the full clockwise position, only the right channel
will be heard. The Balance Control is useful for balancing the acoustic output of the system
between left and right speakers, as well as being useful for system troubleshooting.
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