Strange "chorus sound" from my Duck Dunn

[PatrickJohnson]

Hi there,

I wanted to run this by the community, as I am stumped.

My first generation Lakland Duck Dunn (Fralins), which I had modded a while back (added a matching Lakland spec overwound Fralin J, knobs are volume/volume/tone), appears to have developed this strange "chorus" type shimmer. It may have always been there and I never noticed, but since the band has moved to IEM, it shows up in our ears and also shows up on board mix recordings. I play through a GK Fusion and a RBH 115 cab. I have a Sadowsky Pre/DI pedal in there right before the amp.

It sucks, frankly. With TI flats, this thing is supposed to be all booty and thumpy. Now it has this weird shimmer. Think light chorus. With steel roundwounds, it's more pronounced.

I was thinking the pickups might be out of phase, or maybe they're too low. Am I on the right track? I've ruled out the Sadowsky, all my effects, and the Preamp tubes, as my other bass, an 1980 Ibanez RS-924 sounds brilliant.

Can anyone shed light?

Thanks so much.

Patrick
Louisville, Kentucky

 

[FourBanger]

Twisted strings?

 

[PluckyThump]

What you describe is often caused by the pickups being too close to the strings.

 

[timmus]

I had that same problem on the E string on my MIM Fender Jazz...it took me a while but I figured out that the E string slot in the nut was cut way too wide. I put in a new nut and it went away.

In rereading your post, it sounds like it's on all strings. Is this the case?

 

[StuartV]

Good ideas to check out, so far. One other thing to check is if the pickup is getting microphonic.

 

[Gaolee]

Try minor adjustments if you don't like it.

I had something like that with the Ric. It did it unplugged and was some kind of odd resonance in the body or neck. I liked it, but it disappeared when I adjusted the neck a little.

 

[PatrickJohnson]

Wow. So grateful for the feedback. I will try all of these things.

It has been happening on all strings. Bizarre to me.

Not sure how I can tell if a pickup is getting microphonic, but I'll look that up on my own.

The bass needs a setup anyway, so maybe I'll have them check all the things noted: nut, pickup heights, microphonic, neck relief, etc.

Thanks so much!

 

[xaxxat]

What you describe is often caused by the pickups being too close to the strings.

+1

 

[PotsdamBass8]

I think you can check for microphonics by tapping on the pickups (not the strings, and not with a metal object). There shouldn't be any sound coming through. If there are springs under the pickups, they might be vibrating too. You can stick foam in the spring to stop that.

In addition to everything else suggested, also check the springs in the bridge. Try playing the bass unplugged and listening for it. You can also smack the strings a few times and listen if anything is vibrating afterwards.

 

[PatrickJohnson]

I loved the Fralin video! Nice!

I have a gig tonight, so I made some adjustments based on what I learned from this thread. I hope I see some improvement!

Thanks!

 

[JTE]

TIs are very flexible strings, and therefore more likely to be affected by the magnetic pull of the PUPs than more typical strings.

BTW, I never heard all booty and thump from TIs. I still have a set because they have s great balanced sound, but they don't sound at all like traditional flats.

Booty and thump are more like GHS Precision Flats or LaBella 760 Old Originals (or whatever they call them now).

John

 

[Ric5]

What you describe is often caused by the pickups being too close to the strings.

yes the magnets pull on the strings and create false harmonics.

 

[lowphatbass]

I would start with a good set-up, possibly lowering the pickups. I don't know what your signal chain is but you may consider cutting some highs out of your monitor feed, maybe use a filter.

 

[Jim Carr]

What happens if the Jazz pickup is turned down all the way?

 

[groooooove]

i've never had that happen from pickups too close. maybe super strong magnets, though.

it's most likely the nut or bridge saddles. do all the strings do it?

 

[ROOTSnFIFTHS]

I have had that issue and solved it through pickup height adjustment (lowering). I would try that first.

 

[Tagruvto]

I would suggest that you look at the variables, step by step.

Does it sound like this through all amps?
Does it sound like this with no amplification?
Does it sound like this when only one pickup is selected?
Do you have some other strings available to try?
Does it sound like this with a different guitar cord?
etc.

Exhaust the possibilities one by one...

 

[Roy Vogt]

What you describe is often caused by the pickups being too close to the strings.

That's usually the culprit, IME.

 

[bass_69]

I have a '67 jazz bass that gets this same chorus like sound on only the G string when I get the pups up too high.. It becomes a lot more prounounced the further up the neck I play. I figure it is the magnetic pull of the PUPs.. The problem is that I like the sound on the other 3 strings. It is a lot clearer and more focused with the right amount of growl. I read something about being able to adjust the pole pieces of pickups.. I have some Lollars on another jazz that are staggered. Can the pole pieces be pushed up on the A & D strings so I can then lower the pup to avoid the problem on the G ? Remember this is a vintage instrument and I don't want to damage anything..

 

[mongo2]

Can the pole pieces be pushed up on the A & D strings so I can then lower the pup to avoid the problem on the G ? Remember this is a vintage instrument and I don't want to damage anything..

To do so risks damaging the pickup.