G.R.A.S. Sound & Vibration
Signal Conditioning Power Modules
Power Module Type 12AA
The 12AA Power Module is a two channel, battery operated, microphone power supply, amplifier and filter unit. It has two 7-pin LEMO 1B input connectors for microphone and preamplifier connection as well as two BNC output connectors. Both channels have overload indicators and gains of -20dB, 0dB, +20dB or +40dB. The A-weighting filter fulfills the requirements in IEC Standard 60651 “Sound Level Meters” Type 0. The high-pass filters are 3-pole Butterworth filters with a cut-off frequency at 20 Hz. The 12AA has a battery indicator to monitor the battery condition and an input connector for external power supply. The 12AA has a built-in 1kHz precision calibration generator, with adjustable levels for the two channels. The generator can be activated either with a front panel button or remotely. The Power Module cabinet is 1/12th part of a standard 19” rack. With the rack mounting system Type AK0040, 12 off 12AA Power Modules can be mounted in a standard 19” rack.
| Channels: | 2 Lemo 1B 7 pin microphone inputs 2 BNC outputs |
| Gain: | -20 dB, 0 dB, +20 dB, +40 dB, +50 dB |
| Preamplifier supply: | 28 V or 120 V |
| Polarization voltage: | 200 V or 0 V |
| Frequency response: | 3.5 Hz-200 kHz |
| A-weighting filter: | IEC 60651 Type 0 |
| Output impedance: | 30Ω |
| Power supply: | 10 x AA alkaline batteries or 12-18 Vdc Line adapter for 220 V or 115 V |
