Odd noise from one pickup

[tauzero]

I hadn't noticed this on the Sei when I bought it, but today at rehearsal it was rather evident.

The bridge pickup is making some rather odd noises (other than my playing, that is). Not humming, not major crackling, but irregular thudding and crackling. I've either got a social club secretary sat in the bass tapping a microphone, as social club secretaries are wont to do, or some issue.

When the blend control is fully to the bridge pickup, there is no extraneous noise. Moving it even slightly to the neck pickup brings the noise in.

I've made a recording at [url="http://tauzero.co.uk/MP3s/sei_noise.mp3"]http://tauzero.co.uk/MP3s/sei_noise.mp3[/url] - this is initially on bridge pickup only (no noise), then I strum a couple of strings, then move to the neck pickup and strum again. The noise is pretty clearly audible.

Not sure what the pickups are. Preamp is a Bartolini. This happens both in my lounge (where the recording was made) and in the rehearsal studio, and using three different leads, three different amps, a bass trainer, and no effects.

Does anyone have any suggestions as to cause and remedy?

[Ou7shined]

I suspect maybe something to do with the pre.
Re-solder the bridge and the neck pups in the opposite positions on the pre or balance pot and see if the neck stars doing it.

[gjones]

[quote name='tauzero' timestamp='1333316438' post='1600083']
I hadn't noticed this on the Sei when I bought it, but today at rehearsal it was rather evident.

The bridge pickup is making some rather odd noises (other than my playing, that is). Not humming, not major crackling, but irregular thudding and crackling. I've either got a social club secretary sat in the bass tapping a microphone, as social club secretaries are wont to do, or some issue.

When the blend control is fully to the bridge pickup, there is no extraneous noise. Moving it even slightly to the neck pickup brings the noise in.

I've made a recording at [media]http://tauzero.co.uk/MP3s/sei_noise.mp3[/media] - this is initially on bridge pickup only (no noise), then I strum a couple of strings, then move to the neck pickup and strum again. The noise is pretty clearly audible.

Not sure what the pickups are. Preamp is a Bartolini. This happens both in my lounge (where the recording was made) and in the rehearsal studio, and using three different leads, three different amps, a bass trainer, and no effects.

Does anyone have any suggestions as to cause and remedy?
[/quote]


To start with resolder the neck pickup. If that doesn't work you may have dirty/dodgy pots which may need to be replaced. I have a similiar problem with the selector switch on my P/J bass. It's around 30 years old and needs a service pretty desperately.

Edited April 1, 2012 by gjones

[tauzero]

I didn't do any soldering but did have a good inspect. It's a Bartolini TBIBT, with passive pickups. Battery is 9.5V with a lead plugged in (ie. under load). The preamp has two buffer preamps which feed the blend pot(s) which then feed the tone control section. My suspicion is that something has gone duff in the neck pickup buffer circuit, perhaps an electrolytic gone to meet its maker. Looks rather like it's encapsulated though (it's tucked away and I didn't want to try persuading it out).

I've also found a reference to a Pedulla with the same issue - it uses the same preamp. However, the owner swapped it out for something else so there's no further diagnostics.