Possible Dumb Question but Think about it.

[bl2112]

Common Knowledge says metal conducts electricty. So we run wires from the pick up and under the bridge to the pots by soldering to continue the current. But the pots are metal and mounted to the control plate by metal washers and nuts to a metal control plate (on a jazz at least). Wouldn't this cause some kind of unwanted buzz, besides what we get from single coils pickups?

[dmusic148]

No. This arrangement 'drains away' airborne electrical noise to ground, like a sponge.

[bassteban]

Thought about it; I think any unwanted buzz is in your head, as I'm not getting any. Hope this helps.

[bl2112]

dmusic what do you mean?

[scottbass]

All of the metal surfaces of the pot casings, bridge, control plate, etc. are electrically connected to the ground side of the circuit. They are isolated via various insulating materials from the "hot" or signal side of the circuit. The only way the ground side of the circuit can introduce a "buzz" is if an electrical signal with a reference voltage different than ground is electrically connected to the ground circuit. RF (radio frequency) is prevented from causing a "buzz" by surrounding the "hot" or signal side of the circuit in a metallic cage or "shield" which is electrically connected to the ground side of the circuit. So the pot casings, bridge, control plate, etc. actually contribute to shielding the signal from RF. A buzz will occur only if an electrical current at a voltage different than ground is electrically connected to one of the grounded surfaces.

[bl2112]

Makes since. Only thought of this since I was working on my jazz last night.

Thanks

[dmusic148]

OK. Electricity always follows the path of least resistance, and it always wants to go to ground. The purpose of the shielding and grounding in your bass is to gather up as much airborne electrical noise(humming, radio signals, etc.) as possible. Not to actually block the noise, but rather, gather it up like an antenna. All the metal parts in the bass become this antenna, which is connected to ground. The noise becomes an electric current once it hits metal. Since the metal is all connected to ground(-), the current goes there instead of into your pickups/pots, because going straight to ground is easier. It gets to ground because the sleeve(-) of your guitar cable is actually connected to the 3rd prong on your amp's power cord, which is of course connected to ground.
That's why you will often notice more noise if you eliminate the 3rd prong with an adapter plug- the noise now has nowhere to go, so your onboard circuits pick it up instead, and send it right to your amp.

[BigOldHarry]

I learned a great deal as a kid about basic electronics working on guitars (I replaced the p'ups in my '77 jazz shortly after I got if for xmass in... 1977!). One thing I learned about guitars is that correct grounding is *key*. Shielding helps too!

[bl2112]

Shielding meaning copper in the control cavitity?

[dmusic148]

Yes, copper tape works great because it vacuums up noise, and you can solder it to the ground lug on your jack.

[bl2112]

ground lug?

[GODSBASSMAN]

Originally Posted by bl2112

ground lug?

Jack terminal that holds the black wire = ground lug.

[bl2112]

Ok

I'm only learning.....

[GODSBASSMAN]

Me too - all the time. Happy to help when I can.

[Rick Auricchio]

Originally Posted by dmusic148

Yes, copper tape works great because it vacuums up noise...

Aha, I though I was hearing a fan inside my bass...it was the vacuum!

[greenboy]

Originally Posted by Rick Auricchio

Aha, I though I was hearing a fan inside my bass...it was the vacuum!

You won't hear that once you put your conductive tin foil hat back on ; }

[bongomania]

Originally Posted by Rick Auricchio

Aha, I though I was hearing a fan inside my bass...

Talk about a small audience!

[bl2112]

How much of a difference will I hear if I do the shielding?

[dmusic148]

Originally Posted by Rick Auricchio

Aha, I though I was hearing a fan inside my bass...it was the vacuum!

lol...

Originally Posted by bl2112

How much of a difference will I hear if I do the shielding?

If the bass is quiet(no noise when not playing, but turned up to normal levels) you won't hear any difference at all.

[bl2112]

It would nothing to the single coil buzz tho right?