Crown PowerTech PT 3.1 User manual

PT 3.1
POWER-TECH SERIES
• Rugged, professional power amplifier built
for the road.
• Quick-access front panel power switch and
level controls. Turn-on delay for loudspeaker
protection.
• Patented ODEP ®circuitry and Grounded
Bridge™design combine to provide perfor-
mance and reliability that surpass traditional
designs.
•Easy to read signal presence (SPI) and distor-
tion (IOC ®) indicator for each channel.
•High damping factor provides superior
control over low-frequency drivers for a
clean, accurate low end.
•Bridge-Mono and Parallel-Mono modes make
it easy to optimize the amplifier’s perfor-
mance for a wide range of loads.
•Balanced phone jack inputs in parallel with
XLR input connectors.
•Complete protection against shorted outputs,
mismatched loads, overheating, input/output
DC and high-frequency overload; full internal
fault protection.
•Three-year, No-Fault, fully-transferrable
warranty completely protects your investment
and guarantees its specifications.
It’s hard to please every crowd. But you’ll
have a better chance when you use a Crown
Power-Tech .1 Series amplifier. Musicians
and DJs alike demand a lot from their sys-
tems—clean, punchy sound; reliability; rug-
gedness; smaller size; less weight—all at a
reasonable price. And Crown PT .1s bring
these benefits and much more to the table.
That’s because at Crown, we’ve built our repu-
tation around legendary sound and support.
Power-Tech .1 Series amplifiers are compact,
professional stereo power amplifiers engi-
neered to meet the most demanding sound
reinforcement needs. They compare very
favorably to more expensive amplifiers, pro-
viding uncolored sound and signal-to-noise
ratios commonly associated with recording
studios. Plus, every Power-Tech .1 amplifier is
backed by Crown’s unequaled Three-Year, No-
Fault, fully-transferrable warranty that covers
everything.
With over five decades of experience designing
and building rock-solid products, Crown is the
standard in amp technology. So check out the
affordable, “all-Crown” Power-Tech .1. They
are a powerful argument for quality and value!
For more details about the Power-Tech .1
Series, contact the Crown Technical Support
Group at 800-342-6939 or 219-294-8200.
Also, visit the Crown Audio website at
www.crownaudio.com.
Specifications
The following applies to units in Stereo mode with 8-ohm loads
and an input sensitivity of 26 dB unless otherwise specified.
120 VAC, 60 Hz Units: refers to amplifiers with dedicated
transformers for 120 VAC, 60 Hz power mains.
International Units: refers to amplifiers with special multi-tap
transformers that make them configurable for several AC
mains voltages and line frequencies.
Performance
Frequency Response: ±0.1 dB from 20 Hz to
20 kHz at 1 watt.
Phase Response: ±10 degrees from 10 Hz to
20 kHz at 1 watt.
Signal-to-Noise: A-weighted, better than 105
dB below full bandwidth power. Better than 100
dB below full bandwidth power from 20 Hz to
20 kHz.
Total Harmonic Distortion (THD): Less than
0.05% at full bandwidth power from 20 Hz to 1
kHz increasing linearly to 0.1% at 20 kHz.
in Bridge-Mono and 2 to 4 ohms in Parallel-
Mono mode.
Required AC Mains: Power requirements are
provided on each unit’s back panel. 120 VAC,
60 Hz and 100/120/220/240 VAC, 50 to 60
Hz (non-convertible) units are available. Rated
AC mains voltages are ±10%. Quiescent power
draw is 90 watts or less. 100 and 120 VAC units
draw up to 15 amps of current; 220 and 240
VAC units draw up to 7 amps.
Low-Voltage Power Supply: A ±24 VDC fan-
former supply (fan motor winding) regulated to
±15 VDC.
AC Connector: An appropriate AC line cord and
plug are provided. North American units have
a standard 3-wire, 15-amp grounded connector
(NEMA 5-15P).
Controls
Power: A front panel push button switch used
to turn the amplifier on and off.
Level: A front panel rotary potentiometer for
each channel used to control the output level.
Stereo/Mono: A three-position back panel
switch used to select Stereo, Bridge-Mono or
Parallel-Mono mode.
Sensitivity: A three-position switch behind the
input module used to select the input sensitivity
for both channels: 0.775 volts or 1.4 volts for
standard 1 kHz power, or 26 dB voltage gain.
Reset: A back panel push button switch used to
reset the circuit braker that protects the power
supplies.
Features
Intermodulation Distortion (IMD): (60 Hz and 7
kHz 4:1) Less than 0.05% from less than 171
milliwatts to full bandwidth power.
Damping Factor: Greater than 1,000 from 10
Hz to 400 Hz.
Crosstalk: Greater than 90 dB below full band-
width power from 50 Hz to 4 kHz, rising linearly
to greater than 70 dB at 20 kHz.
Controlled Slew Rate: Greater than 13
volts/ms.
Voltage Gain: 84:1 ±6% or 38 dB ±0.5 dB at
0.775-volt sensitivity; 46:1 ±6% or 33 dB ±0.5
dB at 1.4-volt sensitivity; 20:1 ±6% or 26 dB
±0.5 dB at the maximum level setting.
Power
Output Power:
Load Impedance: Safe with all types of loads.
Rated for 4 to 8 ohms in Stereo, 8 to 16 ohms
For more details about the Power-Tech .1
Series, contact the Crown Technical Support
Group at 800-342-6939 or 219-294-8200.
Also, visit the Crown Audio website at
www.crownaudio.com.

Crown International
P.O.Box 1000
Elkhart, IN 46515-1000
TEL:[phone]
FAX:[phone]FAX
www.crownaudio.com
06/01 133377-1
Crown’s Three-Year, No-Fault, Fully Transferable Warranty
Crown offers a Three-Year, No-Fault, Fully Transferable Warranty for every new Crown ampli-
fier—an unsurpassed industry standard. With this unprecedented No-Fault protection, your new
Crown amplifier is warranted to meet or exceed original specifications for the first three years of
ownership. During this time, if your amplifier fails, or does not perform to original specifications,
it will be repaired or replaced at our expense. About the only things not covered by this warranty
are those losses normally covered by insurance and those caused by intentional abuse. And the
coverage is transferable, should you sell your amplifier.
See your authorized Crown dealer for full warranty disclosure and details. For customers outside
of the USA, please contact your authorized Crown distributor for warranty information or call
219-294-8200.
PT 3.1
Specifications subject to change without prior notice. Latest infor-
mation available at www.crownaudio.com.
Crown, IOC, ODEP and Grounded Bridge are registered trademarks
of Crown International. Other trademarks are the property of their
respective owners. Printed in U.S.A.
© 2001 Crown Audio, Inc.
Indicators
Enable: This red indicator shows the on/off
status of the low voltage power supply.
Signal/IOC: Each channel has a two color indi-
cator that flashes green to show signal pres-
ence and yellow if the amplifier causes distor-
tion of 0.05% or more.
Input/Output
Input Connector: Balanced 1/4-inch phone
jacks and XLR connectors in parallel.
Input Impedance: Nominally 20 K ohms, bal-
anced; 10 K ohms, unbalanced.
Output Connector: Two sets of color-coded
binding posts.
Output Impedance: Less than 10 milliohms in
series with less than 2 microhenries.
DC Output Offset: Less than 10 millivolts.
Output Signal
Stereo: Unbalanced, two-channel.
Bridge-Mono: Balanced, single-channel. Chan-
nel 1 controls are active; Channel 2 controls
should be turned down and not used.
Parallel-Mono: Unbalanced, single-channel.
Channel 1 controls are active; Channel 2 con-
trols should be turned down and not used.
Protection
Power-Tech .1 Series amplifiers are protected
against shorted, open or mismatched loads;
overloaded power supplies; excessive tempera-
ture; chain destruction phenomena; input over-
load and high-frequency blowups. They also
protect loudspeakers from input and output DC,
as well as providing protection from turn-on/
turn-off transients.
If operating conditions are unreasonable, the
patented ODEP circuitry proportionally limits
the drive level to protect the output transistors,
particularly in the case of elevated temperature.
A thermal switch imbedded in the transformer
protects the power supplies from overload. In
the rare event that a transformer overheats, the
thermal switch removes power, waits until the
unit has cooled to a safe temperature and then
resets itself.
Turn On: Four-second delay with no dangerous
transients. Contact us if you need to change
the delay.
Construction
Durable black finish on steel chassis with spe-
cial “flow-through”ventilation from front to
side panels.
Cooling: Internal heat sinks with forced-air
cooling for rapid, uniform heat dissipation.
Dimensions: Standard 19-inch (48.3-cm) rack
mount width (EIA RS-310-B), 3.5-inch (8.9-cm)
height and 16-inch (40.6-cm) depth behind the
mounting surface.
Approximate Weight: Center of gravity is 6
inches (15.2 cm) behind front mounting sur-
face.
120 VAC, 60 Hz Units: 36 pounds, 8 ounces
(16.6 kg) net; 40 pounds, 8 ounces (18.4 kg)
shipping weight.
International Units: 37 pounds, 3 ounces (16.6
kg) net; 40 pounds, 15 ounces (18.6 kg) ship-
ping weight.