What to check

Check the DC voltage output at the power supply. The normal voltage setting is 9V; the higher the voltage the higher the speech volume.

Please note - there are two types of door amplifier;

3 terminal - marked E, D and C

4 terminal - marked +, -, E & D

These notes only apply to 3 terminal door unit amplifiers

Corrective Action

Adjust the DC voltage in the power supply as required.

To adjust the DC voltage use a combination the white fly leads on the transformer tappings in accordance with the table printed on the label on top of the transformer.

Additional notes

3 terminal part ref: 92ETXAMP (pre 2015)