G.R.A.S. 12AR 2-Channel Power Module

Connection: Traditional 200 V
Channel(s): 2

Typical Applications and Use

  • General-purpose measurements
  • Two channels
  • Precision measurements
  • Acoustic monitoring
  • Microphone calibration
  • 0 V or 200 V polarization


The 12AR can be powered either by internal standard batteries or an external DC supply (4.5 V- 24 V), e.g. a mains/line adapter. It is built into a sturdy anodized aluminium cabinet.

The polarization voltage for the microphones fitted to the preamplifiers can be set to 0 V — for prepolarized microphones, or 200 V — for externally polarized microphones.

The 12AR also supplies ± 15 V to power the preamplifiers. It will run for approximately 30 hours on fresh standard alkaline batteries. A Low Batt LED indicates the condition of the batteries.

The inputs are two 7-pin LEMO sockets on the front panel, which are wired up for G.R.A.S. microphone preamplifiers, e.g. 26AB, 26AC, 26AJ and 26AK, but is also compatible with other available makes of similar microphone preamplifiers.

The signals from the preamplifiers are AC coupled to the outputs which are standard BNC sockets also on the front panel.


All G.R.A.S. products are made of high-quality materials that will ensure life-long stability and robustness. The 12AR is delivered with a 2-year warranty. The warranty does not cover products that are damaged due to negligent use.

Service and Repairs

All repairs are made at G.R.A.S. International Support Center located in Denmark. Our Support Center is equipped with the newest test equipment and staffed with dedicated and highly skilled engineers. Upon request, we make cost estimates based on fixed repair categories. If a product covered by warranty is sent for service, it is repaired free of charge, unless the damage is the result of negligent use or other violations of the warranty.

Frequency response (±0.2 dB) Hz 0.05 to 200 k
Output channel(s) 2
Output impedance Ω 30
Type Traditional power supply (LEMO)
Input channel(s), traditional power supply 2
Preamplifier supply V +-15
Polarization voltage V 0 / 200
Power supply, battery 4 x LR6 (AA)
Power supply, external Vdc 4.5 to 24
Power consumption mA 45
Battery life h 30
Battery low indication Yes
Fuse mA 160 (slow)
Weight g / oz 540.00 / 19.05
G.R.A.S. Sound & Vibration reserves the right to change specifications and accessories without notice.
G.R.A.S. AB0005 Mains/line adapter
G.R.A.S. Sound & Vibration reserves the right to change specifications and accessories without notice.