Amp hum

[FLHX]

I have a Marshall 3202 and there is a loud hum coming out of it when I crank it up. Is that the 60Hz hum from the transformer or is there a problem? My Crate G600XL doesn't have that hum.

[Plank_Spanker]

Does it hum without anything plugged in?

Have you tried different power outlets?

[tunghaichuan]

I have a Marshall 3202 and there is a loud hum coming out of it when I crank it up. Is that the 60Hz hum from the transformer or is there a problem? My Crate G600XL doesn't have that hum.

Another thing I would suspect would be the electrolytic caps in the power supply. There is a 33uF/450v for the PI tube, and two 50uF/500v for the screen and plate supplies. These amps are getting to be 20+ years old, and the electro caps do dry out after a while.

Since there are lethal voltages present in the amp, I would recommend that you take it to a competent tech to have it looked over.

I used to own one of these, I never should have gotten rid of it. :thwap

[ZMAN]

To reduce the hum as Plank Spanker mentioned I plug directly into a wall outlet. No extension cords or power bars. That will kill quite a bit of the hum. If you are plugged into the wall then I would say there is some issues.
I have a 2008 DSL100 and it has a slight hum. I went to premium guitar cables and that helps a lot. But the biggest issue for me was the power.
I purchased a pedal board with a conditioned power supply and that makes all the difference.
One day my wife unplugged it to clean and plugged it into a power bar that I had for my TV and Stereo.
I picked up this loud hum and thought one of my pedals was fried. It took me a whole day of testing each pedal, to finally find the main plug for the board plugged into the power bar. It was behind a couch. I plugged it into the wall and it was dead quiet.
Hope that helps.

[FLHX]

I plug straight into the wall. The hum went away when I unplugged the guitar cable. I use monster cable so the next step will be eliminating my pedal board.