Buzz on high volume

[Baxlin]

I have a budget-end EB-2 shape semi acoustic bass as a backup to my EB-3, and using it yesterday the sound man pointed out a mains hum type buzz when the volume on either humbucker was turned up.  As it’s on both, I assume it’s not either volume pot, but anyone any ideas please?  I tried different inputs, and different leads.  I’ve had the jack socket come loose in the past.

Thanks in advance for any help.

Malcolm

Edited April 23, 2018 by Baxlin

[EliasMooseblaster]

A few thoughts spring to mind:

1. Duff/no shielding - how easy are the controls to access? If you can get inside easily this can be fixed relatively easy.

2. Loose earth wire - typically in contact with the bridge, but can work loose.

3. Do you have separate tone controls for each pickup, or one master? I've had a capacitor fail on a P bass before, which led to a rather prominent buzz. Could be this problem if you've only got the one tone control...or both could have failed, but that's less likely!

[Baxlin]

Thanks, separate tone for each p/u.

Accessing controls is only via jerjiggling through the f sound holes.  Assuming this is possible (they must have been fitted this way?) how would I add shielding, please?

Thanks again

[EliasMooseblaster]

Unfortunately I dont know he best answer to that - afraid I've never had to fiddle with the insides of a semi-hollow before. Anyone else on here have any ideas?

[BigRedX]

Are you sure the pickups are humbucking? The size of the casing is no real indicator of the type of pickup contained within, especially on budget instruments. Even my Warwick Starbass II with it's massive pickup covers they are only single coils.

[MoonBassAlpha]

Good point BRX, a lot of old Japanese guitars had humbucker sized housings containing single coil gubbins.