Changing Line Voltages on the 40-A2
The internal power supply of the 40-A2 Loudness Monitor contains a dual-primary power transformer that is normally shipped configured for 117VAC operation. To reconfigure the meter for 230VAC operation (or back to 117VAC), you will need to remove the meter from its enclosure.

Locate the power transformer on the circuit board. Right next to the transformer are two resistors marked 117V, and 1 resistor marked 234V (highlighted area in illustration below).

If the two 117V resistor are stuffed in the circuit board, the meter is set for 117V operation, while if the single 234V resistor is in place, the meter is set for 230V operation.

To change input voltage, simply remove the resistors for the undesired voltage, and install the resistor(s) for the desired voltage (the resistor(s) for both ranges are 1 ohm).

Reassemble the meter and verify that the AC line connector is appropriate to the new power mains outlets.



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