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.
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
Power-Tech 1.1: Greater than 75 dB below full bandwidth power from 50 Hz to 2 kHz, rising linearly to greater than 60 dB at 20 kHz.
Power-Tech 2.1: Greater than 90 dB below full bandwidth power from 50 Hz to 2 kHz, rising linearly to greater than 66 dB at 20 kHz.
Power-Tech 3.1: Greater than 90 dB below full bandwidth 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: 20:1 ±6% or 26 dB ±0.5 dB at the maximum level setting.
Power-Tech 1.1: 54:1 ±6% or 35 dB ±0.5 dB at 0.775-volt sensitivity; 30:1 ±6% or 30 dB ±0.5 dB at 1.4-volt sensitivity.
Power-Tech 2.1: 66:1 ±6% or 36 dB ±0.5 dB at 0.775-volt sensitivity; 36:1 ±6% or 31 dB ±0.5 dB at 1.4-volt sensitivity.
Power-Tech 3.1: 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.

Power
Load Impedance: Safe with all types of loads. Rated for 4 to 8 ohms in Stereo, 8 to 16 ohms 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 (unconvertible) units are available. Rated AC mains voltages are ±10%. Quiescent power draw is 90 watts or less.
Power-Tech 1.1: 100 and 120 VAC units draw up to 6 amps of current; 220 and 240 VAC units draw up to 3 amps.
Power-Tech 2.1: 100 and 120 VAC units draw up to 10 amps of current; 220 and 240 VAC units draw up to 5 amps.
Power-Tech 3.1: 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 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 1.1 and 2.1.
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 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 (Power-Tech 3.1 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 and XLR connectors in parallel.
Input Impedance: Nominally 20 K ohms, balanced; 10 K ohms, unbalanced.
Output Connector: Two sets of touch-proof 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 .1 Series 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 1.1: 30 pounds (13.6 kg) net; 34 pounds (15.4 kg) shipping weight.
Power-Tech 2.1: 33 pounds (15.0 kg) net; 37 pounds (16.8 kg) shipping weight.
Power-Tech 3.1: 36 pounds, 8 ounces (16.6 kg) net; 40 pounds, 8 ounces (18.4 kg) shipping weight. 
International Units:
Power-Tech 1.1: 31 pounds, 2 ounces (14.1 kg) net; 34 pounds, 9 ounces (15.7 kg) shipping weight.
Power-Tech 2.1: 35 pounds, 12 ounces (16.9 kg) net; 38 pounds, 13 ounces (17.6 kg) shipping weight.
Power-Tech 3.1: 37 pounds, 3 ounces (16.6 kg) net; 40 pounds, 15 ounces (18.6 kg) shipping weight.

Crown's Three Year, Full, No-Fault Warranty