Extra hum: - normal or not.

[mickeyj4j]

Ok so i have a Karina bass guitar. It is an Ibanez SR clone. it has a split P pickup and a jazz pickup near the bridge. Also play through a Roland Cube 20xl Bass amp at home.

Pickups:- Karina

• mickeyj4j
• Nov 17, 2014

The pickups.

What i am experiencing is a clicking sound in the amp at times when lightly plucking the strings. also i hear an extra hum like an unplugged cable. The hum gets worse when i turn up the tone knob. The extra hum does go away when i touch any of the strings.

Is this normal. if not is there anything that i can do to fix it.

**EDIT** I have just remembered while ago i tested my guitar amp plugged into wall and it gave a lot or noise. comparing to running on battery and no noise. I assume this is due to old wiring in my house. still going to try and shield my bass. I wonder why so many bass and electric guitars have very poor quality or no shielding at all, judging by research i have done.

 

[Precision101]

It means your bass is grounded properly. When you touch the strings you yourself are grounding it. A shielding project should fix it. Had the same problem on both of my p basses until I shielded them. Since the Jazz pickup is single coil the hum will be inevitable but shielding with decrease this. Get a roll of copper foil tape off stewmac and do it yourself.

 

[LoveThatBass]

In addition to shielding the pickup and control cavities I would consider installing a good dual coil low noise J pickup also. Try the shielding 1st. Any hum you would get would come mainly from the front side of the bass then.

 

[DiabolusInMusic]

Shielding will have no effect on 60hz hum that you experience from the single coil jazz pickup. You would need a humbucker to affect this.

As the others have said, your bass is experiencing RF interference. You need to give the bass a proper shielding job to remedy the issue. It is a rather common issue and a simple fix.

Also, do not buy any shielding supplies from stew-mac. Their shielding supplies are highway robbery. Go on ebay and buy four times the product for half the price. Be sure to buy double-side conductive tape. You can also source it locally from stained glass supply shops. Personally, I much prefer paint to tape, but they both work equally well.

 

[dincz]

Check that your bridge is grounded. Do you have a multimeter?

 

[BrBss]

Check that your bridge is grounded. Do you have a multimeter?

If the noise goes away when he touches the strings, then the bridge is likely grounded.

 

[dincz]

If the noise goes away when he touches the strings, then the bridge is likely grounded.

If the bridge is effectively grounded then touching the strings will make no difference.

 

[Steve Dallman]

dincz, That makes no sense. If the bridge is grounded, touching the strings would cut the hum. If not grounded, touching the strings would make no difference.

 

[iiipopes]

If the bridge is effectively grounded then touching the strings will make no difference.

No. It makes all the difference in a conventional passive instrument.

 

[BlueTalon]

Still, the multimeter is your friend in situations like this. If you don't already have one, it's worth the $8 - $30 you're going to spend on it.

Regarding the initial noise issue, I'll echo other comments here that you need to get a hum canceling J pickup, shield the internal cavities, and make sure your bridge and all the shielding is grounded. It's probably best to do it all in one motion, since you have to take the bass partially apart to do any one of those anyway.

 

[Precision101]

Like I said before touching the strings and the buzz diminishing means that the bridge is grounded. Theres electrical current in your body so when you touch it it stops.

 

[dincz]

Like I said before touching the strings and the buzz diminishing means that the bridge is grounded. Theres electrical current in your body so when you touch it it stops.

Electrical currents in your body are shunted harmlessly to ground when you touch any grounded point in a circuit.

 

[mickeyj4j]

It means your bass is grounded properly. When you touch the strings you yourself are grounding it. A shielding project should fix it. Had the same problem on both of my p basses until I shielded them. Since the Jazz pickup is single coil the hum will be inevitable but shielding with decrease this. Get a roll of copper foil tape off stewmac and do it yourself.

I assume you mean it is NOT grounded properly. what did you do to fix this. Would like to know so i can also do the same. thanks.

 

[BlueTalon]

Mickey, is the J pickup in your PJ bass a single coil pickup?

 

[Precision101]

I assume you mean it is NOT grounded properly. what did you do to fix this. Would like to know so i can also do the same. thanks.

The bridge is grounded I meant. The cavity isn't. Shielding does the trick.

 

[mickeyj4j]

The bridge is grounded I meant. The cavity isn't. Shielding does the trick.

Thanks I understand now. i just need to find a good tutorial on how to apply the Shielding and clean up this bass.

 

[Precision101]

Thanks I understand now. i just need to find a good tutorial on how to apply the Shielding and clean up this bass.

Well, you can get some copper or aluminum foil tape and line the inside of the cavity with it watertight. You don't have to desolder anything, but take out the pots and pickups. I think you can get some copper foil tape cheap on Amazon.

 

[DiabolusInMusic]

Thanks I understand now. i just need to find a good tutorial on how to apply the Shielding and clean up this bass.

http://www.talkbass.com/threads/jazz-shielding-pictorial-big-images-warning.159191/

 

[mickeyj4j]

another thing i would like to know is what type of pickup/pickups you would recommend. I dont have much budget to spend. but can look on eBay etc to find great bargains. Just need to know what i need.

 

[BlueTalon]

I highly recommend Fender Super 55 pickups. They're out of production now, but they can still be found, and for good prices. Here's one on Amazon.

To answer your question, what you are looking for is a hum canceling J pickup to match with your hum canceling P pickup. There are several varieties of them, the two main ones being split-coil and stacked coils. The Fender Super 55 is a split coil pickup -- like the P pickup, except it's made to fit a J cover. A lot of companies make them, but you won't be able to touch them for anything close to the price on Amazon.