My amplifier is making a very loud humming noise

The loud humming is the sound of AC mains - clearly your amplifier is receiving an input from somewhere and possibly into the front end.

The hum could be induced by radiated energy from nearby unshielded equipment, it could be the result of an accidental hum-loop or could be because the amplifier power supply has a fault.

It is usual practice with amplifier construction to ensure unused inputs are shorted to ground by switching or by additional contacts and wiring at the input sockets. High gain high impedance inputs can cause a great deal of unwanted noise if they are not shorted.

I suggest you read the instruction manual and perhaps Google a few hints and tips about amplifiers and stuff.

I would check the caps on the power supply. They are rather large electrolytic capacitors that will look like they burst and/or leaking. When these die, the caps ground and the sub will make a loud buzzing sound. If you are handy with a soldering iron you can replace them yourself. Replace them with the same voltage or a little bigger and same with the size.

If the cap. says 16v 4700pF on it, for example, a 20v 5300pF or a 16v 6200mF cap. will work for this application.

Are your grounds to BARE metal sounds like a ground loop issue.

Humming , these depends on what kind? or how loud is the humming.

On most it is from faulty regulator or worst from the amplifier and preamp

These may needs further troubleshooting, have a tech to guide you.

Let us know what you find or needs further assistance.

4 possibilities:
1) ground loop or open connection on input.
2) close proximity to a CFL, or other flourescent fixture.
3) bad filter caps in the sub.
4) bad coax to the sub.

in any event, check wire routing. You can also track down the noise sources by using a portable AM radio tuned off station. it will pick all manner of RF noise around the house. Light dimmers are notorius noise makers.

Hello
Switch on your amp, keep its volue down to extreme low, and listen if there is still hum through the left channel or not. If still there is hum, the left side power amplifier section inside the amp;ifier is faulty. If htere is no hum at this state, hum enters thorugh the audio input terminal, and the input wires must be checked for open sheild connection. OK.

your capacitors may be blown , if its a solid state amplifier ..

if its tube version (best) , you may have blown a tube

what model number is it , manufacturer ?

verify all connectons, make sure you don't have something crossed.

It sounds like a filter capacitor(s) has failed. The electrolytic caps dry out and cease to perform allowing unfiltered power to reach the preamp sections and get amplified.

Being this is tube with high voltages, an experienced person should work on it due to shock danger.

I assume you checked the tubes for shorts as well as emission since a heater to cathode short could cause this as well.

you might have your gain level too high or frequencies