Influence of scale length on pickup position: J-type basses

[michael sharpe]

I built a 35 inch scale 5-string fretless bass some years ago, and have never really been happy with the sound from the bridge pickup on its own: it's just sort of flat and uninteresting. I am wondering if because of the longer scale and hence higher string tension, the pickup positions, relative to the nut, for example, need to be different in order to get the classic J bass sound sound. I'm assuming that the higher string tension creates a different pattern of harmonics, etc., compared with a 34 inch scale J-type bass. You can see from the photo that I have already shifted the pickups once, so that they are closer to the nut. The neck pickup has a great P-bass type tone, and the two together create a great tone, but I would like to have better tone from the bridge PU. Maybe I'm expecting too much, and the 35 inch scale is just a different beast.

Any suggestions welcome.

The body is ash, quite heavy, with a couple of thin cherry strips remaining from the previous body parts (re-built during Covid). The thru neck is a lamination of sycamore and hornbeam, with an ebony fingerboard, two carbon-fibre strips for stiffening, and a double action truss rod. The pickups are 20-year-old Seymour Duncan Basslines single coil passive. The pots are bog standard, nothing special.

[Barry Daniels]

I've only built a few basses so don't have a ton of experience with them. But my experience with electric guitars tells me that pickup placement is not that sensitive. For one thing, as soon as you fret a string, the pickup position is thrown into a totally different relationship to the vibrating string length, but you don't usually hear that much difference in tone. I think most of the tone is determined by the type of pickup. So, you might want to try a different brand of pickup. Also, be aware that many basses use active systems which can provide much more control over tone.

[michael sharpe]

Thanks for that. I did have an onboard preamp for some years, but decided to go back to the simplicity of a passive setup. I did wonder about installing a higher output bridge pickup, ie alnico. Of course quite a lot can be done with a good EQ.

[Jarno Verhoeven]

Somewhat old thread (remember this place to be livelier 20 years ago ), but on bass pickup position and type (especially shape of the coils) will have quite an influence on the sound. I myself (bassplayer) like J-bass bridge with a smidgeon of J-bass neck, on a Jazzbass-esque instrument, but that beefy Musicman Stingray sound or indeed a precision is also pretty cool, and all have their place. But yeah, bridge pickups will have low output, so I usually have a preamp in there with a buffer per string, wouldn't shift pickups towards neck though, that is a bit woolly for my taste.
You could try to replace the bridge pickup with a higher output one like a musicman stingray pickup (see Lakland 55-02 model).
On lengthening scale length pickups shift toward neck because harmonics on the vibrating strings shift (if you want to keep the same sound).
If you have the pickup positions measured from the bridge, simply multiply them with 35/34 .
I made a 5 string shortscale which I wanted to have the Stingray vibe, so I shifted the single pickup towards bridge (by multiplying with 30.7/34), worked out pretty well.

[michael sharpe]

That’s really helpful, thanks. I just bought a set of Fender pickups with Alnico V magnets, so hopefully that will improve the output of the bridge pickup. And I may shift that one a little bit closer to the neck.

[Jarno Verhoeven]

You might need to mix-n-match, so choose a pickup with low output for the neck position (if the string spacing and pole piece location allows, in some sets the pickups are not equal length) and a higher output pickup for the bridge position, or, two J pickups for the bridge position.


Berry Oakleys "Tractor" bass had two jazz pickups near the bridge (and a darkstar in neck position).