Passive preamp hummmmms HELP!!

sha975 · #1 02-25-2006, 08:51 PM

Does all passive bass guitars hum and have ground problems due to the lack of a active pre? I wastold that most passive bass guitars hum especially with the pickups rolled to one side. Is this true? If not can someone post a diagram on how to properly wire a passive bass. The knobs are vol, blend, and passive tone control. I get bad hum when I'm far away from the amp and some of the hum goes away if I touch the strings or bridge or cable for that matter. Help me Please! I hate this hummm with a passion.

**Blackbird** · #2 02-25-2006, 09:00 PM

It would have been helpful if you mentioned what kind of bass you play.

Sounds the instrument is not shielded and you're picking up 60 cycle hum.

Look up "Shielding" in the Setup & Repair forum. There should be a few threads about that.

sha975 · #3 02-25-2006, 09:04 PM

The bass is a used benavente and the bass is shielded with cooper shielding

orlfl · #4 02-26-2006, 04:23 AM

All single coil pickups hum. It is not an active/passive thing as much as a what kind of pickups. You can shield and often get rid of some of it but single coils inherently hum.

What kind of pups does it have? Have you looked to see if a ground wire has come loose?

TheSuzie · #5 02-26-2006, 05:03 AM

Yes all single coil pickups can act as antennas and sometimes a bit of shielding right around the pickup can help. There are other factors that can influence the extent of the problem.

Try a different cord. Try plugging your amp into a different circuit. Try standing in a different place or facing a different direction while playing. A very important thing to note is what other electrical equipment is nearby. Is there flourscent lighting around, light dimmers, video monitors, things with motors like a refrigerator. All of these things are evil....

Shoot, its getting light outside.
S

Magneto · #6 02-26-2006, 08:44 AM

You might also want to check your electrical supply for proper grounding. Some older homes with older wiring do not have a proper ground.
My AC here at home is not grounded. I use a dedicated grounded plug for my amp. Without it, I get hum, even from my active bass.

Mag...

Bass · #7 02-26-2006, 08:30 PM

Quote:

Originally Posted by sha975

...If not can someone post a diagram on how to properly wire a passive bass....Help me Please! I hate this hummm with a passion.

I hate hum too: the first link has wiring diagrams as requested. The second link explains the "star" grounding system. I did the star modification on a strat and it made a world of difference.

http://www.guitarelectronics.com/cat...ickupdiagrams/

http://www.guitarnuts.com/wiring/shielding/shield3.php