Niggling earth noises - Grrrr!

[dudewheresmybass]

Hi all

I've put a seymour spb2 into a bass yesterday.

I've checked the grounding from strings all along to jack with a multimeter, but there's still a slight earth noise when not touching metal work.

I'm at a loss as to what can be going on. 

It's frustrating me as I was intending to use it at a 3k+ festival on Saturday.

Any ideas please?

 

TIA

[paul_5]

Might not be grounding - could be a shielding issue. Are the cavities lined with conductive tape and linked to the ground wire?

[dudewheresmybass]

Yes mate. 

[JapanAxe]

It’s not unusual to get some buzz when you’re not touching the strings or bridge. When you are touching them you become an earthed shield against interference; when you’re not, you’re not (unless you touch something else that’s earthed, like the shell of a mic.) Shielding the pickup and control cavities may help (must be earthed of course).

 

Did you have the same issue with the previous pickup?

[Phil Starr]

It’s probably radio frequency noise. The strings (probably) act as an aerial and subsequent components rectify that and turn it into audio noise. Changing the pickups re-tuned the system and may be responsible. You can’t win this, sometimes it’s your body that acts as the aerial 😊 I had this the other day with my supposedly noiseless pickups. Moving to another room solved that one.

 

Its often more noticeable if you have the early gain stages set too high and some fx exacerbate the problem.

[dudewheresmybass]

@JapanAxe the previous pup was silent as are the others in my arsenal. 
@Phil Starrin my practice space I’m not using much more than a minimal gain for a touch of grind. 
 

the bass is shielded to within an inch of its life lol. It’s just a strange anomaly. I will have to make sure I’m in contact with something on the sustained notes. 
 

thanks for all of your suggestions chaps.