Humming from 1949 Tweed Pro

[ezra1]

When I play my Teles and some P90 guitars the amp has an annoying hum when you aren't playing.
It has the original 2 prong ac cord.
I am thinking this needs to be replaced with a 3 prong grounded plug. ?

[xtian]

Hi, Ezra, welcome to the board. As you've noticed, single coil pickups (Strats, Teles, P90s) do not reject hum like humbuckers do. Updating your amp to an earthed 3-conductor plug is definitely a good idea for your safety. Do it! But it's not going to help with the noise of single coil pickups.

[pompeiisneaks]

And to add to the wise comments by xtian, if it's old enough to have two prongs, it should likely be looked at by a tech to see if the electrolytic capacitors are going. They can add more hum to the amp but its a different hum, faster than the 60 cycle hum of the wall power, instead it's rectified 120hz hum due to the post rectified filter capacitors not cleaning up the power like they used to when new.

~Phil

[Colossal]

To add to the above...a little more history of the amp would be helpful, and, because it is a real piece of history, interior photos would be great to see. This will also tell us if it is stock or has been serviced/modified in the past. As well as the power supply capacitors, it would be good to know if the tubes have been changed recently or in the past, or even original.

[ezra1]

I have been hoarding back up tubes.

[ezra1]

It is 60 cycle hum. Distance from the amp is the only thing that will help. 5 to 7 feet is too close.
No issues with humbucker pickups.