Hafler P7000 User Manual
P7000
PROFESSIONAL POWER AMPL
Installation & Operation
®
®
trans
nova
DESIGNED AND
ASSEMBLED IN THE
USA
PROFESSIONAL POWER AMPLIFIER
NOTICE - IMPORTANT SAFETY INFORMATION
The lightning flash with arrowhead symbol within an equilateral triangle
CAUTION
RISK OF ELECTRIC SHOCK
DO NOT OPEN
WARNING: TO PREVENT FIRE OR
SHOCK HAZARD, DO NOT EXPOSE THIS
EQUIPMENT TO RAIN OR MOISTURE.
!
!
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 maintenance (servicing) instructions in the literature accompanying the appliance.
1. READ INSTRUCTIONS
All the safety and operating instructions of your Hafler equipment
should be read before power is applied to the equipment.
2. RETAIN OWNER'S MANUAL
These safety and operating instructions should be retained for
future reference.
3. HEED WARNINGS
All warnings on the equipment and in the operating instructions
are important and should be followed.
4. FOLLOW INSTRUCTIONS
All operating and use instructions are important and should be
followed.
5. HEAT
The equipment should be kept away from areas of high temperature, i.e., heater vents, radiators, stoves/ovens, fireplaces, etc.
6. 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.
7. 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.
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.
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
8. 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.
9. POWER CORD PROTECTION
Power cords should be arranged so 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 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
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.
– i –
P ERFORMANCE SPECIFICATIONS
P7000
Power Rating: FTC (20Hz-20kHz, <0.1% THD) EIA (1kHz, 0.1% THD)
350 wpc into 8Ω 375 wpc into 8Ω
500 wpc into 4Ω* 525 wpc into 4Ω*
1000 wpc into 8Ω* 1050 wpc into 8Ω*
*Continuous sine wave power limited by current rating of line fuse.
Signal-to-Noise: 100dB below rated output from 20Hz to 20kHz
Frequency Response: ±0.1dB, 20Hz to 20kHz
+0/–3dB, 0.2Hz to 100kHz
Slew Rate: 100 V/µs
Input Impedance: 47,000Ω per phase
Input Sensitivity Range for rated output power:
Unbalanced: 1.7V-9.5V RMS (8Ω), 1.4V-8V RMS (4Ω)
Balanced: 0.85V-4.75 RMS (8Ω), 0.7V-4V RMS (4Ω)
Gain: +15dB min. / +30 max.
CMRR: –75dB at 1kHz
Damping Factor: 600 (to 1kHz); 200 (to 10kHz); 25 (to 100kHz)
Power Consumption: 275 VA quiescent.
1440 VA with both channels driven at 350 watts at 8Ω, 1800 VA maximum.
Controls & Switches: Front Panel: Power switch, Normal/Bridged mode switch, level controls
Rear Panel: Chassis/Float ground switch, Stereo/Bi-amp selector switch
Crossover: Variable high-pass, low-pass and bandpass; 100Hz as supplied
Indicators: Power lamp, Clip, Short, Thermal, Signal LEDs
Connectors: Input: 2-way XLR and 1/4" Tip Ring Sleeve
Output: 5-way binding posts spaced for dual banana plugs
Power: IEC 320
Dimensions: 19"W x 127⁄8"D x 31⁄2"H plus 11⁄8" for handles, includes rear supports
(48.3cm x 32.7cm x 8.3cm plus 2.875cm for handles, includes rear supports)
Net Weight: 40 lbs. (18.18kg)
– ii –
T ABLE OF CONTENTS
SAFETY PRECAUTIONS ........................................................................................................................................... i
PERFORMANCE SPECIFICATIONS ......................................................................................................................... ii
INTRODUCTION ................................................................................................................................................... 1
INSTALLATION
Location ........................................................................................................................................................... 2
AC Line ............................................................................................................................................................ 2
Input................................................................................................................................................................. 2
Input Crossover ................................................................................................................................................ 3
Input Mode Switches ........................................................................................................................................ 3
Output Connections ......................................................................................................................................... 3
OPERATION
Power Switch ................................................................................................................................................... 4
Level Controls .................................................................................................................................................. 4
XCard Crossovers ............................................................................................................................................. 4
Ground Switch ................................................................................................................................................. 5
Short Circuit Protection .................................................................................................................................... 5
LED Indicators .................................................................................................................................................. 5
Warm Up ......................................................................................................................................................... 5
Cleaning and Maintenance ............................................................................................................................... 5
TECHNICAL REFERENCE
Field Service Considerations ............................................................................................................................. 6
Theory and Operation of trans•
PC Board Layout............................................................................................................................................... 7
Schematic Diagram .......................................................................................................................................... 8
Parts List ......................................................................................................................................................... 10
P7000 Functional Block Diagram ................................................................................................................... 12
Circuit Operation ........................................................................................................................................... 13
Amplifier Module Replacement ...................................................................................................................... 16
Building Custom XCards ................................................................................................................................. 17
Resistor Chart ................................................................................................................................................. 18
WARRANTY ......................................................................................................................................................... 19
nova ................................................................................................................
6
I NTRODUCTION
The Hafler P7000 is a two channel professional power amplifier suitable for use in any sound reinforcement
situation where faithful, accurate reproduction is required. The amplifier uses forced air fan cooling to deliver
high power output in a compact size. Status indicators on the front panel give a visual representation of
amplifier and system operation. Input configuration switching and active crossovers enhance the flexibility
when used in multiple amp systems, without requiring the use of additional equipment. The use of our
patented trans•nova circuit topology and MOSFET output stage ensures reliable, long term operation which
is backed by our five year warranty.
This manual contains information on using the P7000 amplifiers. It is organized into three main sections.
“Installation” covers the location and connection of the amplifier in the system. Like many precision
components, careful attention to the initial setup can yield dividends in higher performance and trouble-free
use. “Operation” covers the controls and features of the amplifiers and how to use them to get the best effect.
The “Technical Reference” section contains field service information; in addition to the schematic and parts
list there are block diagrams and circuit operation explanations useful for technicians. We strongly urge
reading over the Installation and Operation portions of this manual before putting the amplifier into service.
The circuitry used in the Hafler Professional power amplifiers is our trans•nova (TRANSconductance NOdal
Voltage Amplifier, US Patent 4,467,288) circuit. The P7000 also utilizes our proprietary DIABLO (Dynamically
Invariant AB Linear Operation, patent application in progress) transconductance driver stage which combines
the linearity of Class A operation with the current headroom of a Class B system. When combined with the
robust output stage used in the P7000, DIABLO yields lower high frequency distortion without the sonic
penalties associated with increasing the negative feedback. We have been using MOSFETs in our power
amplifiers since the 1970s. During this time, they proved to be extremely fault tolerant, even in abusive
situations. This ruggedness enables the amplifier to drive reactive speaker loads without the performance and
sound penalties imposed by elaborate Safe Operating Area protection schemes.
Active crossovers are incorporated at the input of the amplifier. These crossovers are controlled through the
use of our XCard plug-in modules. Each XCard can operate as a full-range, high-pass or low-pass filter with a
12dB per octave Butterworth alignment. Each channel utilizes two XCards which in combination can be
configured as a 24dB per octave slope or a 12dB per octave bandpass filter. Since the XCard contains the resistors
and capacitors that establish the crossover Q and frequency; specific system requirements can easily be
accommodated just by changing the component values.
Input configuration switches allow the amplifier to be configured for conventional stereo, two channel mono
or single channel bridged use. When the amplifier is run in two-channel mono mode, the level controls and
crossovers for each channel are fully functional which allows for using the amplifier as a single channel in a
bi-amped system.
Specialized circuits which prevent damage to the amplifiers and speakers have been carefully implemented to
avoid affecting the audio signal. A soft start circuit prevents sending potentially destructive turn-on and turnoff transients to the speakers. A thermal sensing network monitors the heatsink temperature and shuts down
the amplifier to protect it from excessive operating heat. The need for internal fuses has been eliminated; a
sensing circuit monitors the output and shuts down the power when it detects a short in the output load.
Each channel of the amplifier has been built as a self-contained module. This modular arrangement simplifies
construction and improves service accessibility. The circuit board assembly makes extensive use of surface
mount components in the low power portion of the audio circuitry. Automated equipment is used to place and
solder the components which yields greater uniformity and reliability.
The front panel has controls for input level adjustment and the power switch. In addition, LED indicators give
a visual representation of the operating status of each channel. The THERMAL and SHORT indicators light to
show when these protection circuits have been activated. The clip indicator helps prevent damaging the
speakers by showing when the amplifier is overdriven. The SIGNAL indicator lights to show the presence of
an audio signal.
– 1 –
I NSTALLATION
LOCATION
The P7000 uses forced-air fan cooling to remove the heat produced in normal operation. Although this makes
the amplifier less sensitive to ventilation than if it were passively cooled, fresh air flow at the mounting location
must still be considered. The fan pulls in fresh air through the side vents and the heated air is forced out through
the front panel. Another consideration when choosing the location for a fan cooled amplifier is its proximity
to the listening position. In some situations the sound of the fan operation can be distracting.
The power transformer can generate a substantial magnetic field, so caution should be exercised in the
placement of low level components such as a tape deck, mixer or mic preamp to avoid inducing noise in the
low level circuitry. Allow several inches of clearance when mounting these components.
AC LINE
The P7000 operates from a 120 volt, 60Hz AC power line. Connection is made by 14 gauge, IEC Type 320,
grounded line cord. For safety considerations only a properly grounded (earthed) receptacle should be used.
If a grounded circuit is not available do not break off the ground pin; use the proper adapter plug for a two wire
receptacle. The power line fuse is mounted on the rear panel of the amplifier. If this fuse blows replace it only
with the same type and rating fuse. The correct replacement fuse value is printed on the rear of the amplifier
and in the parts list.
INPUT
The input jacks used on the P7000 are dual function connectors which accept 1/4" (Tip Ring Sleeve) phone and
XLR plugs. The amplifier will operate with either a balanced or unbalanced signal source. The connector pinout is printed on the rear panel of the amplifier.
Balanced Input: 1/4" Tip Ring Sleeve
The 1/4" balanced input jack is connected according to conventional usage with the Tip high (+), Ring
return (–) and the Sleeve ground shield.
Balanced Input: XLR
The XLR balanced input jack is connected according to the IEC and AES Standard, with pin 2 high (+),
pin 3 return (–) and pin 1 ground shield. When preparing to use the amplifier, check the output
configuration of the source unit to maintain the proper signal polarity.
Unbalanced Input
Many popular mixers use unbalanced RCA phono or 1/4" phone jacks for the monitor outputs and can
be used with the P7000 for short cable runs. The specifications for the mixer should give the maximum
cable length it is capable of driving. The return (–) terminal must be grounded when using the amplifier
with the input unbalanced to prevent unstable operation.
Unbalanced Source with Balanced Input
Some systems will have a noticeable amount of residual ground noise when run with unbalanced signal
lines. Better noise rejection can be achieved in these systems by using shielded, twisted pair (balanced)
cable from the unbalanced source. At the source end of the cable, connect an RCA or 1/4" phone plug
with the return (–) wire and shield connected to the ground terminal of the plug. Wire the plug at the
amplifier end of the cable the same as for the regular balanced input connection described above.
– 2 –
INPUT CROSSOVER
The XCard crossover modules are plug-in cards located inside the amplifier. The P7000 is shipped with 100Hz
XCards in each channel. Since each XCard can operate full range, high-pass or low-pass, with a 12dB per octave
slope, this allows the amplifier to be used in a wide range of applications. XCards are available for a variety of
frequencies from your dealer or through our Customer Service department.
To order additional XCards call Customer Service at 800-669-9899. Office hours are 8:00 a.m. to 5:00 p.m. MST,
Monday through Friday. All orders are pre-paid and VISA and MasterCard are accepted.
INPUT MODE SWITCHES
Two-Channel Stereo
To run the P7000 in two-channel mode, set the front channel NORMAL/BRIDGED switch in the
NORMAL position and set the rear panel STEREO/BI-AMP switch to the STEREO position. This
configures the amplifier for conventional left and right stereo operation.
Dual Mono
The rear panel STEREO/BI-AMP switch configures the input connection required by the amplifier.
With the switch set for STEREO Channel 1 and Channel 2 require separate input signal source feeds.
When the switch is set for BI-AMP the Channel 1 input feeds the signal to both amplifier channels for
dual-mono operation. The level control and XCard for each channel are still active.
Bridged Mono
In systems with higher power requirements, the P7000 can be configured for signal channel, bridged
mono operation. To bridge the amplifier, set the front panel NORMAL/BRIDGED switch to the
BRIDGED position. Only the Channel 1 input and level control is used and the Channel 2 level control
and XCard are not active. The speaker is connected to the RED output binding posts. When the
amplifier is bridged, the output is floating. Any speaker which requires a common ground from the
amplifier output cannot be used in this application. Since a bridged amplifier shares the load between
the two channels, each channel will effectively drive half of the load. Therefore, for bridged operation
we recommend using an eight ohm load as the minimum impedance.
OUTPUT CONNECTIONS
The speaker output connectors are dual binding posts which will accept wire up to 12 AWG. They are spaced
on 3/4" centers for use with dual banana plugs.
– 3 –
O PERATION
POWER SWITCH
The POWER switch is located on the front panel of the amplifier. An internal lamp indicates when it is turned
on. Standard practice is to turn the amplifier on last and off first when switching components individually to
prevent sending damaging transients, generated in the source components, to the speakers. It is possible to
leave the power switch in the on position and switch the amplifier remotely through a power distribution
block or preamp switched outlet. When doing so make sure the switch is rated for the current required by the
amplifier.
LEVEL CONTROLS
The input sensitivity, for each channel, can be adjusted individually using the level controls on the front panel.
The gain control on an amplifier is usually fully advanced to its maximum (rated) sensitivity. In public systems
where it is necessary to match levels, the knobs can be removed and the controls adjusted with your fingers
or a flathead screwdriver. Cover the holes with the enclosed plugs to restrict access.
INPUT CONFIGURATION SWITCHES
Stereo/Bi-Amp
The rear panel STEREO/BI-AMP switch controls the signal routing in the amplifier. In the STEREO
position, the signal is supplied independently to Channel 1 and Channel 2. In the BI-AMP position,
the signal is fed to both amplifier channels from the Channel 1 input, while retaining full use of the
level controls and XCard crossovers. This allows the amplifier to be used in dual-mono or bi-amp
systems without requiring auxiliary equipment.
Normal/Bridged
The amplifier operates in two-channel mode when the front panel NORMAL/BRIDGED switch is in
the NORMAL position and the rear channel switch is set for STEREO. To use the amplifier in single
channel, bridged mono applications, the front panel switch must be in the BRIDGED position. When
the switch is set in the BRIDGED position, the Channel 1 (+) and (–) inputs are connected to Channel
2 in reversed polarity, which inverts the Channel 2 output. Only the Channel 1 input is used, and the
speaker is connected to the two RED binding posts. The amplifier gain is adjusted by the Channel 1
level control; the Channel 2 control is not active. Because of thermal considerations we do not
recommend using less than a nominal eight ohm load on the amplifier when running it in mono.
XCARD CROSSOVERS
The XCard modules contain the resistors and capacitors which control the frequency at which the card
operates. The orientation of the card in the socket determines the operating mode of the crossover. The XCard
is labeled to indicate the function of each face. The full range face is marked with a double arrow to show that
both edges operate full range. The other face operates as either high-pass or low-pass and an arrow is printed
by the function to indicate which edge to insert into the socket.
Each amplifier channel uses two XCards. When both cards are set full range, the full frequency response of
the amplifier is used. When one card is set full range and the other for either high-pass or low-pass, the signal
is crossed over at 12dB per octave with a Butterworth alignment at the frequency determined by the card which
is used. When both cards are set for the same operation, whether it is high-pass or low-pass, the signal is crossed
over at a 24dB per octave slope. When one card is set for low-pass and the other for high-pass, a bandpass
crossover limits the signal to the frequency range determined by the cards which are used. The slope of the
filter is 12dB per octave. There is no effect on the bandpass operation regardless of which of the cards is used
for the high-pass or low-pass function.
Assembled XCards are available at a variety of operating frequencies. Since there will be situations which the
stock cards will not satisfy, instructions for building XCards for specific applications have been included in
the Technical Reference section of this manual.
– 4 –
Loading...