mddawson,
Tell me did you check today?
For amplifiers in mV, can you tell me how many mV the amp salesperson will help you with?
Tell me did you check today?
For amplifiers in mV, can you tell me how many mV the amp salesperson will help you with?
No, I haven't checked yet. My amplifier plays music at normal volume. The problem is that there is a lot of background noise behind the music. Once I have reduced/removed that noise, I can then check other settings.
I rewired the power supply in my FM711 and that removed 80% of the noise. There is still a little noise there under input load but you need to stick your ear up to the speakers to hear it. Before I could hear it from my seating position 4m away. Note, only two amplifiers I have used have used in my system have had zero background noise, a Hypex Nilai and a D9 NHB-108 clone.
I tested the 12v transformer by disconnecting from the circuit and using a desktop power supply to trigger the amplifier boards and there was no difference in the noise so it is now back in circuit. Just shows how critical power supply wiring can be.
Here are before and after photos:
I tested the 12v transformer by disconnecting from the circuit and using a desktop power supply to trigger the amplifier boards and there was no difference in the noise so it is now back in circuit. Just shows how critical power supply wiring can be.
Here are before and after photos:
Can anyone tell me where the test points for the FM711 amplifier boards are and what readings I should be seeing? There are three trimmer resistors per channel but I don't want to mess with them until I know what I am doing. Thanks in advance.
I am also thinking of adding the four capacitors from the original damaged amplifier board (they test fine) to my FM711 to see if that tightens up the bass response.
I am also thinking of adding the four capacitors from the original damaged amplifier board (they test fine) to my FM711 to see if that tightens up the bass response.
ask the supplier who sold you the FM amplifier so that he can tell you how to set up the FM 711
What are the testing conditions? At idle or playing a test tone? With or without speaker load?