Rattle and hum

[owen_liam]

Hello all!

My bass has developed a very irritating rattle somewhere in the scroll - right by my ear! I've had a good look and cannot find anything obviously wobbly or moving around. I had the bass repaired recently and I was wondering if it could be something to do with how they put the strings back on.

Any suggestions at coming to a diagnoses and solution?!

Thank you!

[Eric Hochberg]

Ends of strings vibrating against peg box, loose tuning keys or gears, these are the only things I can think of short of a cracked scroll (don't know if that would make a noise...).

[Paul Warburton]

On fingered notes only, on open strings only or all notes?
On open strings only, may be a nut groove problem.
Like Eric said, check all the screws on your machines, especially full plate machines that have screws holding down the plates.
Sorry, that's enough to drive you up the walls.

EDIT: The "hum" thing you mention could be the plate itself vibrating against the scroll cheek. I had to take the whole thing out and beef up the cheek with a little shim once to stop that. A luthier should do that for you though. (IMO).

[owen_liam]

Thanks guys. The rattle is more pronounced on certain fingered notes than on open strings. I'm guessing that there must be something vibrating around the machines or perhaps the string ends in the box like echoberg suggested.

I guess the best thing to do is get the strings off and check the screws, plates etc and then put them back on to see if anything changes.

[David Potts]

Another source of rattle is the tuning"knob" - that thing that your fingers wrap around to turn the screw of the machine (someone please tell me what it should be called!!!). With cheap machines this is often a brass or chrome plate riveted into a slot in the worm gear shaft. If this is knocked(eg getting in or out of a car) it can bend, loosen and rattle. I suggest tapping each of these plates with a knuckle. You will hear the rattle and be able to rock the plate in its slot. My emergency solution - blu tac. A longer lasting solution - perhaps superglue or Araldite.

Beware the screw (and washer) that are on the "other" end of the tuning peg to hold it in its position. As you alter the string tension up and down the peg will rotate but the screw may not rotate with it if the peg is too short to protrude through the cheek of the peg box. On my bass I have to slack off this screw during string changes until the new string is almost up to pitch then tighten it . If I don't do this I feel I could crack the side of the peg box because the screw will lock itself tight to that extent. Then, if I forget to tighten the screw I will get that rattle for sure.

Each source of peg box rattle has its own distinct character.

Cheers......

DP

[Jake deVilliers]

Originally Posted by David Potts

Another source of rattle is the tuning"knob" - that thing that your fingers wrap around to turn the screw of the machine (someone please tell me what it should be called!!!). With cheap machines this is often a brass or chrome plate riveted into a slot in the worm gear shaft. If this is knocked(eg getting in or out of a car) it can bend, loosen and rattle. I suggest tapping each of these plates with a knuckle. You will hear the rattle and be able to rock the plate in its slot. My emergency solution - blu tac. A longer lasting solution - perhaps superglue or Araldite.

Beware the screw (and washer) that are on the "other" end of the tuning peg to hold it in its position. As you alter the string tension up and down the peg will rotate but the screw may not rotate with it if the peg is too short to protrude through the cheek of the peg box. On my bass I have to slack off this screw during string changes until the new string is almost up to pitch then tighten it . If I don't do this I feel I could crack the side of the peg box because the screw will lock itself tight to that extent. Then, if I forget to tighten the screw I will get that rattle for sure.

Each source of peg box rattle has its own distinct character.

Cheers......

DP

How about 'tuning key'? And yes, they do like to buzz...

[owen_liam]

Originally Posted by Paul Warburton

The "hum" thing you mention could be the plate itself vibrating against the scroll cheek. I had to take the whole thing out and beef up the cheek with a little shim once to stop that. A luthier should do that for you though. (IMO).

It never ceases to amaze me that I can gather the thoughts of such illustrious and experienced players and luthiers! Thanks guys.

Beginning to think that Paul is right. The plates don't seem to be perfectly flush against the scroll cheek. Can't find a vibrating tuning key, string ends seem fine. The screws for the plate seem ok. Curiouser and curiouser...

Luckily, the buzz is much less of an issue when you're not the player! When you are playing though, it's right in your left ear: very irritiating!

[Jack Clark]

Originally Posted by Paul Warburton

Like Eric said, check all the screws on your machines, . . .

On my strange bass, this happens repeatedly but not often enough, apparently, for me to think of it right away. Now I carry a tiny screw driver just for those machine screws, and I'm trying to remember to check them first before I begin fretting about a bad string or spot on the my modified fingerboard. One of these times I'll succeed.

[basswraith]

Get the correct screw driver and go around and tighten all the screws. Especially the center screws. Any Loose screw can vibrate and buzz.
Michael Hartery
www.BostonBassWorks.com

[Paul Warburton]

Hey, I got an idea! Tighten the screws.
Jeesh.

[owen_liam]

Not sure where I'm getting this from, but I've been thinking that I might tighten the screws.

I did. It's much better, but still there. Got some new strings coming soon, so when I change them I'll take good notice of what's happening inside the peg box and around the scroll generally.

But it's much better - thanks fellas.

[David Potts]

My last thought on the subject!

When you tune down do you notice that a peg might be sticking momentarily.There may be a little bit of slack to take up before the worm gear engages the cog in the new direction. If the peg is too tightly dry-fitted into the pegbox holes it may not turn readily The slack could be caused by wear, lack of peg lubrication, poor fitting or poor quality of machines. During this slack period the worm gear and shaft can rattle. It only happens when you slacken the strings, not when you are tuning them up.

When you next get your mystery sound try each tuning key, first by touching it then by tuning up slightly, to see if the sound disappears. Some distinct notes may cause the rattle or buzz because they set up more resonance in the bass timbers.

The answer might be to dismantle and remove the machines, ream out the holes slightly more and dry lubricate them with graphite powder before re-assembly. This is a job for a luthier.

DP

[Cody Sisk]

Originally Posted by David Potts

My last thought on the subject!

When you tune down do you notice that a peg might be sticking momentarily.There may be a little bit of slack to take up before the worm gear engages the cog in the new direction. If the peg is too tightly dry-fitted into the pegbox holes it may not turn readily The slack could be caused by wear, lack of peg lubrication, poor fitting or poor quality of machines. During this slack period the worm gear and shaft can rattle. It only happens when you slacken the strings, not when you are tuning them up.

When you next get your mystery sound try each tuning key, first by touching it then by tuning up slightly, to see if the sound disappears. Some distinct notes may cause the rattle or buzz because they set up more resonance in the bass timbers.

The answer might be to dismantle and remove the machines, ream out the holes slightly more and dry lubricate them with graphite powder before re-assembly. This is a job for a luthier.

DP

It might also be a good idea to color in the nut grooves with a pencil liberally while you have the strings slacked. Binding up there might also cause what David's describing.

[Russell Bergum]

I have the same problem on my Juzek. I get a buzz in the scroll/pegbox with an open A and E to a lesser degree, worse with fingered notes between A and B one octave above the open A. Buzz is worse when I slightly back off the tuning key. When I do that, the peg doesn't move right away (ie tone doesn't change) and the buzz gets worse, until I tune it up sharp. I've tightened all the screws on the plates and no difference. Is the problem between the worm gear and housing?

[Russell Bergum]

Originally Posted by David Potts

With cheap machines this is often a brass or chrome plate riveted into a slot in the worm gear shaft. If this is knocked(eg getting in or out of a car) it can bend, loosen and rattle. I suggest tapping each of these plates with a knuckle. You will hear the rattle and be able to rock the plate in its slot. My emergency solution - blu tac. A longer lasting solution - perhaps superglue or Araldite.
DP

Ta Da!

That's it. The brass plate was loose on the G string tuner. One drop of superglue and the buzz is gone. Thanks - saved me a trip to the nearest luthier (60 miles away)! Now I can get back to practicing - it was driving me crazy almost to the point of going Postal.

[Jack Clark]

More recently than my last post on this thread, I experienced a buzzing on G, Ab, and A notes only, no matter where they were played on my fingerboard. It took me two months to locate the cause, which was a loose nut on the pickup jack. I don't use my amp very much.

The moral of the story is that anything that can be tightened or loosened can buzz. So, I made a check list of all of them and keep the list handy. It's easy to entirely forget about a buzzing source when it hasn't raised its ugly head in a year or so. Of course, I'm still learning my odd bass instrument, so a check list like this is still useful to me. You guys who know your instruments cold have had this all worked out long ago.