Omnicron Electronics - Professional Voice Logging Recorders and Accessories - since 1975 
 Professional Voice Logging Recorders  and  Accessories


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Omnicron Electronics - Professional Voice Logging Recorders and Accessories - since 1975

PZ-2LA and PZ-2L
PZ-2LA photo

Pressure Zone room monitoring Microphones with
line level output and AC power adapter (PZ-2LA only).
Click here to view or download PZ-2LA PDF page

The Omnicron PZ-2LA (shown in above photo) and PZ-2L Microphones are Pressure Zone Microphones designed for meeting and conference recording. They look like a switch, not a microphone, so as not to draw attention.

Like other Pressure Zone Microphones, they use a miniature microphone capsule mounted near a sound reflecting plate. In this zone, direct sound from the source combines in phase at all frequencies with reflected sound. The benefits are many: 6 dB more sensitivity, 6 dB less noise, a wide smooth frequency response free of phase interference, excellent clarity, and consistent pickup anywhere around the microphone. A built-in amplifier provides a high level output. Power for the amplifier in the PZ-2LA is provided by an AC power adapter which is supplied with the PZ-2LA microphone. The PZ-2LA comes with a cable for connecting to the 3.5mm "AUX" input on Omnicron analog recorders and with a cable for connecting to the RJ-11 jack on digital recorders. The PZ-2L is for use with Omnicron CR-1 standard speed or CR-4 one quarter speed conference recorders, they are powered by the CR-1 or CR-4 recorders. The high level output permits longer cable runs than possible with a standard microphone.
The PZ-2LA microphone come with cables pre-wired for use with recorders that have a 3.5mm "AUX" (auxiliary) input jacks or RJ-11 telephone style input jacks. It is supplied with 6' cables that plugs into a supplied junction box. The PZ-2L is pre-wired for use with Omnicron CR-1 and CR-4 recorders.

The PZ-2LA junction box has an AC adapter which plugs into 120 vAC to power the unit, and a 6' cable to connect audio output from the microphone to your recorders line level audio input. Follow the directions supplied with your recorder for recording with the PZ-2LA microphone. If the microphone is located more than 25' from your recorder, standard RJ-11 telephone extension cables can be used. One twenty five foot (25') extension cable is supplied with each PZ-2LA and PZ-2L microphone.
After removing the plastic housing, the microphone can be installed in a ceiling or wall using a standard electrical outlet box. Internal connections to the electronics are as follows:
Power from the 12VDC/AC power adapter connects to INPUT terminals # 1 & # 2.
Audio output connections are made at OUTPUT terminals # 2 and # 3.
If the audio output is connected to equipment that has a balanced input circuit with a separate ground connection, the ground connects to OUTPUT terminal # 1.

The PZ-2LA can also be powered by an external AC or DC source between 8 and 24 volts. Connect it to the electronics circuit board at INPUT screw terminals # 1 and # 2. A balanced audio output is available at OUTPUT screw terminals # 2 and # 3. The recommended minimum load impedance is 1000 ohms. The PZ-2L is wired for use only with Omnicron CR-1 and CR-4 recorders. The PZ-2L plugs direct into the "PZ-MIC-IN" jack on the CR-1 and CR-4 recorders. It will be powered by the recorder.

If the microphone is mounted to a grounded enclosure, ground loops could occur that would cause hum. If hum is present when the microphone housing is connected to ground, remove the resistor labeled GND LIFT on the printed circuit board.

The microphone is factory set to handle sound levels up to 100 dB without excessive distortion. If the sound at the mic will exceed 100 dB, change the plug-in resistor (labeled Gain) for more headroom. Removing the 1.0K ohm resistor and replacing it with a 3.9K resistor will provide 12 dB more headroom with a corresponding lower output signal from weak sounds.


Pressure Zone Electret Condenser l Frequency Response: 80-20,000 Hz l S/N Ratio: 68 dB l Polar Pattern: Hemispherical l Impedance: 75 ohms l Output Level: 1.4 V/Pa (+3 dB re 1 V/Pa) l Maximum SPL: 100 dB 3% THD l Equivalent Noise Level: Less than 26 dB, A weighted l PZ-2LA Power: supplied by an external 120VAC to 12VDC adapter, or 8-24 VAC/DC, 4 ma l PZ-2L Power: supplied by Omnicron VR-1PZ or VR-4PZ recorder l Dimensions: 2" x 3" x 4" l Net Weight: 6 oz without cable l Color: Microphone and Cable are Ivory l Warranty: Limited 1 year parts & labor.

If the unit fails to work, recheck all your connections as described in the Installation Section. Assistance is also available from your place of purchase or from Omnicron. If service is required, return it to Omnicron at the address shown below. Please refer to the warranty statement for warranty details.

PZ Microphone amplifier circuit board

Circuit board layout (top).

PZ Microphone schematic

Schematic Diagram


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                        581 Liberty Highway,  Putnam, CT  06260

(860) 928-0377

(860) 928-6477

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