I have my Notifier AMG-1 wired and programmed to my CPU2-640 everything works fine but I have a constant low pitch hum coming from the fire alarm speaker. Any thoughts on how I can fix this?
May have to adjust the pre-amp gain.
On the older panels, if set too high, it would cause a problem with the handset module.
Try adjusting and listen to the results.
The simple way to fix the supervision tone coming is a control module. There is no real way to remove the 200hz tone you my hear from the AMG-1 unless using the microphone but it goes back into the supervision tone after any operation is back into normal.
Sounds like the output is active even when the audio is off. What is the speaker circuit wired to, how is it programmed?