SPECIFICATIONS INTRODUCTION
8 OHM POWER RATING: 325 watts continuous aver-
age power per channel at less than .025% total harmonic
distortion from 2OHz to 20kHz with both channels driven.
4 OHM POWER RATING: 450 watts continuous aver-
age power per channel at less than .035% total harmonic
distortion from 2OHz to 20kHz with both channels driven.
8 OHM BRIDGED POWER RATING:
900 watts continuous average power at less than 0.035%
total harmonic distortion from 2OHz to 2OkHz.
IM DISTORTION (IHF):
Less than .O 1% from 1 watt to 325 watts, both channels
into 8 ohms.
FREQUENCY RESPONSE INTO 8 OHMS:
-3dB, 4Hz and 1OOkHz at 1 watt
-.5dB, 1OHz and 40kHz at 1 watt
SIGNAL TO NOISE RATIO, UNWEIGHTED:
Exceeds 95dB referred to 325 watts into 8 ohms,
100 dB (A-weighted)
TYPICAL CHANNEL SEPARATION:
2OHz: > 80dB
1kHz: > 75dB
20kHz: > 6OdB
DAMPING FACTOR: 300 up to 1kHz into 8 ohms.,
200 up to 1OkHz into 8 ohms.
SLEW RATE: 1 kHz, 12OV p-p square wave: 40 volts
per microsecond.
VOLTAGE GAIN: 29dB
INPUT IMPEDANCE: 47,000 ohms, balanced
INPUT SENSITIVITY: 1.95 volts rms per phase for
325 watts into 8 ohms.
POWER CONSUMPTION: 12OV 6OHz Line:
325 watts into 8 ohms both channels: 132OVA
450 watts into 4 ohms both channels: 18OOVA
SIZE: 3- 1/2” high, 19” wide, 14” deep behind faceplate,
l-1/2” in front of faceplate including handles
NET WEIGHT: 40 lbs.
SHIPPING WEIGHT: 42 lbs.
ALL SPECIFICATIONS SUBJECT TO CHANGE
WITHOUT NOTICE.
The Hafler PRO5000 is a high power, low profile, two
channel power amplifier intended for professional sound
installations. It is the result of modern packaging combined
with the performance and reliability characteristics found
in previous Hafler designs. The PRO5000 has an optimized
combination of features needed for a professional power
amplifier: high power, small package size, rugged case
construction, balanced inputs, full bridgeability for mono
applications, continuously variable DC fan for quiet op-
eration, and a variety of simple, yet effective protection
systems. Above all, however, the PRO5000 maintains the
well known Hafler tradition of superior sounding power
amplifiers.
OVERVIEW OF AMPLIFIER
The PRO5000 is a standard two-rack height fan cooled
design utilizing fully complimentary drive circuits and
lateral type MOSFET output transistors. The amplifier has
full subtractor balanced input circuits for good noise rejec-
tion. The drive circuitry is a high performance arrangement
with a double differential JFET input stage. Film capacitors
are used throughout the circuitry to ensure minimum deg-
radation of the audio signal.
The 19” extruded aluminum front panel includes handles
for ease of installation, separate gain controls for each
channel, signal present and clipping indicators for both
channels, and the power switch which has a pilot lamp. The
rear panel has both 1/4” phone and XLR connectors for the
inputs, 5-way binding posts for the outputs, a switch to
bridge the amp for mono mode. and a switch to connect or
disconnect the audio ground from the chassis ground.
The protection systems include separate power supply
fuses on DCV+ and DCV- for each channel, thermal
sensing circuits that monitor output device temperature and
correspondingly control the DC fan, a relay to disengage
the load if excessive DC offset is detected or if the output
device temperature becomes too high, a delay to avoid
dangerous turn-on/off transients, and an AC line fuse if all
else fails. This amplifier does not have, and by virtue of
design, does not need the current limiting circuits which are
required to protect conventional bipolar or vertical MOSFET
output devices. The less common lateral MOSFETs used in
Hafler amplifiers inherently limit the current ONLY under
abnormal conditions, thus avoiding ‘thermal runaway’ and
subsequent device destruction. This gives the dual advan-
tage of greater reliability from simpler circuitry, and the
elimination of one of the chief causes of distorted signals -
the harsh sounds of the actuation of complex protective
circuits.
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