Power-Tech Series Power Amplifiers
Page 12
Reference Manual
You must provide sufficient AC power to the amplifier.
Amplifiers do not create energy—they require proper
voltage and current to deliver the power you expect.
Low-Voltage Power Supply:
A ±24 VDC fanformer
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. It is also a circuit breaker for the
power supplies in the
Power-Tech 1 and 2.
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 inside the back
cover plate 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 (see Section 2.3).
Reset (
Power-Tech 3 only):
A back panel push button
used to reset the circuit breaker that protects the power
supplies.
Indicators
Enable:
This red indicator shows the on/off status of the
low voltage power supply.
Signal/
IOC:
Each channel has a two color indicator that
flashes green to show signal presence and yellow if the
amplifier causes distortion of 0.05% or more.
Input/Output
Input Connector:
Balanced
1
/
4
-inch phone jacks (refer
to Section 5 for XLR and barrier block connectors).
Input Impedance:
Nominally 20 K ohms, balanced; 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. Channel 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 controls should be turned
down and not used.
Protection
Power-Tech amplifiers are protected against shorted,
open or mismatched loads; overloaded power supplies;
excessive temperature; chain destruction phenomena;
input overload 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 special “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 surface.
120 VAC, 60 Hz Units:
Power-Tech 1: 30 pounds (13.6 kg) net; 34 pounds
(15.4 kg) shipping weight.
Power-Tech 2: 33 pounds (15.0 kg) net; 37 pounds (16.8
kg) shipping weight.
Power-Tech 3: 36 pounds, 8 ounces (16.6 kg) net; 40
pounds, 8 ounces (18.4 kg) shipping weight.
International Units:
Power-Tech 1: 31 pounds, 2 ounces (14.1 kg) net; 34
pounds, 9 ounces (15.7 kg) shipping weight.
Power-Tech 2: 35 pounds, 12 ounces (16.9 kg) net; 38
pounds, 13 ounces (17.6 kg) shipping weight.
Power-Tech 3: 37 pounds, 3 ounces (16.6 kg) net; 40
pounds, 15 ounces (18.6 kg) shipping weight.
