- Output: 25V, 500 VA
- Direct coupled linear output
- Output voltage and current meters
- Voltage and current source modes
- Small size, high power

The Labworks PA-138 Linear Power Amplifier is a high quality, air-cooled, direct-coupled audio amplifier primarily intended for use with small vibration systems. Although this amplifier has been designed to directly drive low impedance loads, it can be used in any application requiring continuous duty, high quality, audio power. A front panel switch allows configuring the output circuitry as either a low impedance voltage source or high impedance current source. A voltage-proportional-to-output-current output signal is provided for modal test and other applications requiring force monitoring.

PA-138 Amplifiers feature protection from both over current and over temperature ensuring long term reliability. The amplifier has full interlock capabilities as well as peak voltage and RMS current bar graphs to monitor output.

General Specifications
Output voltage 25 V rms
Output current 20 A rms
Max. cont. dissipation 450 W
Frequency response  
  Voltage source: DC - 10 KHz -.6 dB
  Current source: DC - 2 KHz -2 dB @ 4 ohms
Max. current gain 22 A/V
Max. voltage gain 34 dB
Cooling: 2-speed fans, automatic
Input impedance 10 k-ohms
  Volts, pk 19 segment bar graph, 5%
  Amps, rms/pk 19 segment bar graph, 5%
Interlock circuit  
  External, user Ext. switch or TTL
Input Power 1,000 VA max.
  Voltage 100, 120, 220, 240 V, single phase
  Frequency 48 to 62 Hz
Dimensions 3.5"H x 19"W x 13"D
Weight 24 lbs (10.9 Kg)
Amplifier Options
Rack panel cabinet
BNC signal cables