Mark IV humming pls help

[shredding]

Hi,
Just recent put my MK IV into a head shell. Find that when I bring my guitar close to the head (only the head, not the speakers), I observe a loud humming. (this stops when I start strumming). When I turn down the volume on the guitar, the hum is gone. (even in the lead channel with the volume cranked up). ONly when I turn the volume on my guitar up and bring my guitar close to the head will I observe the humming . Is this normal? I put tin coil on the inside but this problem still exists. Is there a short you think?

Thanks!

 

[mrd]

It's normal. All 3 of my amps do it. I think it's because your pickups are picking up electromagnetic interference from the circuits inside the amps. Put your guitar near to a light bulb... same effect. It's just one of those things. It only happens to me if I'm really close to the head though, like less than 3 feet away.

 

[shredding]

mrd, thanks for your quick reply. I appreciate it.

 

[shredding]

thanks, rabies, but I'm using humbuckers which didn't buck the hum.

 

[stomper]

Ditch the tin foil.
Go to a hardware store and buy some aluminum flashing. Staple it to the top of the cabinet. Strip the end of a piece of wire and staple or solder it to the flashing. Make it about about 5 inches long and strip the end. Solder another wire about 5 inches long to the chassis of the amp and strip the end. Twist both ends of each wire together and secure it with a twist nut (those little plastic things you see in electrical outlets). I did this to my 50 Caliber with the sus-4 cabinet and it is quiet as a mouse. The chassis must maintain contact with the shielding, or the amp will hum. You can test this project by running a wire from your tin foil first. Good luck.