Another thread on hum....URGENT

irritantbassist · #1 04-12-2007, 02:23 AM

Okay, I know what you're thinking. Another post on Hum and before someone says it, ive trawled through the other threads and have definitely found it all helpful but im afraid my problem is still giving me grief.

Ive got two 78 fender P Basses one Maple neck and one rosewood.

They both had the exact same upgrades to an SD Quarter Pounder and a BadAss II. The Maple P is awesome, absolutely perfect. However, the rosewood P recently started producing a huge amount of hum. Please note that I had the rosewood upgraded about 6 months before the maple and toured with it with no problem.

I took it to my local tech who is awesome, he knows everything and has sorted any problems I have had before. We spent a whole day re wiring the rosewood after no luck trying every variable. We even switched over the electronics from the maple into the rosewood but it still made the noise, and then when put back into the maple no noise.

The next step was conductive paint. Consulted an electrician and after shelling out £30 for tin the noise was STILL there.

We are now completely stumped.

Its crazy how two (exact same production year) mint condition basses with just fingerboard wood being the only difference can have this problem.

Please note: the rosewood bass makes this noise through my rig, through the techs rig, in the shop and at the practise rooms.

If anyone has any bright ideas would really appreciate the help as the rosewood has now been out of action for 3 months

Niall

napalmito · #2 04-12-2007, 02:27 AM

Is the bridge correctly routed to ground ?
Have you tried the SPB3 of the rosewood, on the maple and vice et versa ?

irritantbassist · #3 04-12-2007, 02:29 AM

Yeah, the bridge is grounded, near ground wire was fitted when the bass was re wired.

I took the pickguard (with all the components still in it) from the maple and put it onto the rosewood. This made no difference to the hum but when I put it back in its original bass (the maple) there was no hum. This is what confused us.

Niall

GlennW · #4 04-12-2007, 03:09 AM

I'd try these before doing anything else.
1) check between bridge and input jack with an Ohmmeter
2) make sure the foil on the pickguard is making contact with cavity shielding

PilbaraBass · #5 04-12-2007, 03:26 AM

Quote:

Originally Posted by irritantbassist

Yeah, the bridge is grounded, near ground wire was fitted when the bass was re wired.

I took the pickguard (with all the components still in it) from the maple and put it onto the rosewood. This made no difference to the hum but when I put it back in its original bass (the maple) there was no hum. This is what confused us.

Niall

what are you saying?

that the maple's electronics hum on the rosewood?

did you try the humming (rosewood's) electronics on the maple?

did you move the pickups with the pickguard?

could be the pickup...

irritantbassist · #6 04-12-2007, 03:37 AM

I took the maples electronics (the perfect ones) and put them into the rosewood but then they still made the really bad hum.

I put them back into the maple and they were fine :S

Shoewreck · #7 04-12-2007, 05:03 AM

Check:
Bridge to ground connection.
Pickup wiring (it will hum if wired improperly).

Nighttrain1127 · #8 04-12-2007, 05:16 AM

Put a piece of copper or aluminum under the ground wire at the bridge for more contact area hum should go away after time the ground wire presses into the wood and does not make good connection using a piece of copper under the wire between the wire and the body about 2 inches long and one inch wide will give it better contact and eliminate hum.