NR Thunderbird problem with hum

[bobyoung]

Anyone here good with Thunderbird wiring? This is a year old NR T-Bird. I'm getting 60 cycle hum when I have both volumes below full with it in an amp I use at a weekly gig, it's not the amp as other basses don't do it there. I'm in Lima, Peru.

The power out here is 220 with one hot wire and a neutral, no grounds.

This one bass also will do it at home with Ampegs but reversing the plug solves the problem with them and none of my other basses hum here with both volumes below full on. I'm pretty sure it's something internal as diming both volumes increases any buzz pickup but eliminates the hum. No bass out of 6 I have here does this besides this T-Bird. The bass sounds great and both pickups sound normal. Any tips appreciated. This is with the same cord, I frequently play a Jazz at this club, also a Fender P/J with both volumes down too and no hum at all.

[bobyoung]

I forgot to add that the hum diminishes considerably when I touch the strings.

[godofthunder]

  Sounds like a ground issue if it diminishes when you touch the strings. Without actually having the bass in  hand it's and difficult to diagnose your problem.  I have no experience running gear with 220. Make sure all your gear is grounded. Shielding may help but my gut tells me that this is a ground issue.

[Alanko]

I forgot to add that the hum diminishes considerably when I touch the strings.

This means your bass has insufficient shielding. The hum reducing when you touch the strings indicates that the bridge is grounded.

[Basvarken]

Bob tells us the amp is not grounded. In the mirror-topic in the Gibson corner Bob told us this is very common in his country.
In my opinion this is the source of all the ground related problems.
When you touch the strings you become the ground connection yourself.
Quite dangerous if you ask me.

[godofthunder]

Bob tells us the amp is not grounded. In the mirror-topic in the Gibson corner Bob told us this is very common in his country.
In my opinion this is the source of all the ground related problems.
When you touch the strings you become the ground connection yourself.
Quite dangerous if you ask me.

   Agreed.

[Gunny]

If you can do so, get a wireless system before your name is on the obituaries.