My first build diary JBA4 Jetblack

If you turn both volumes down, do you still get a sound?

If you haven't played a Jazz bass before (you may be used to a single pickup bass, say a Precision) you should find that there are three basic sounds. Neck pickup only, bridge pickup only and both pickups on full volume. To me there's never a lot of variation in the sound level or tone with say 100% neck and the bridge much less than 80% (or vice versa). Any variation in tone or output is very subtle indeed until the pickups are near equal volume.

So if you have one pickup volume on full and are adjusting the other pickup volume and expecting a wide sweep of tones, you are unlikely to get it.

If the volume pots are working you should get:

Both volumes off - no sound.

Neck volume right up, bridge volume right down - neck pickup.

Bridge volume right up, neck volume right down - bridge pickup.

Bridge and neck pickup both volumes up - mixed bridge and neck position.

Tap the pickup poles with a screwdriver to confirm which pickups are working.

With one pickup volume right off, you should hear the other pickup volume control working as expected.

If you aren't getting that, and its full volume from both pickups all the time, then there's definitely something wrong somewhere, but it can only really be the ground connections to the third lug on the volume pots. You wouldn't get a signal from a pickup if there's no ground connection from the back of the pot to the jack. It may be worth just reflowing those solder connections for each bent tab to the back of the pot with new solder.

"If you aren't getting that, and its full volume from both pickups all the time, then there's definitely something wrong somewhere, but it can only really be the ground connections to the third lug on the volume pots."

Could full volume all the time could be a short between lugs 1 and 2 of either volume pot?

It's certainly a possibility.

So check there are no strands of wire bridging between the outer and central tabs of the volume pots. And check no solder has fallen onto the brown pcb material part of the pot and is bridging between the input and output connections. The last is unlikely, but still worth checking.

Definately a full volume problem, getting sound from both volume controls no matter what position they are in, tone seems to be ok, as you said very little variation, I will do a solder flow check, the wiring does seem a bit flimsy, the original wire to bridge that was on the tone pot fell off before I could do anything with it, so most likely a solder issue. I will also finish off the shielding see if any of that makes a difference. My Pbass is very responsive I soldered new pickups in her a few years ago was fine right from the start, it is also shielded that was becausee I was getting a lot of hum through the amp, it's been a great Bass for many years. I think I may just resolder everything to make sure all connections are good. Thanks again guys appreciated the help.

Attachment 44710Attachment 44711Attachment 44712 Did a complete resolder and completed the faraday cage, I have full working system all volume and tone responding very well.[ATTACH=CONFIG]44713[

Have you dug out that multimeter yet to check for ground continuity and shorts between the input and output connections on the pots?

Edit: Crossed posting.

A P-bass pickup should be humbucking if constructed properly, so you shouldn’t have got much hum at all, regardless of shielding. As the coils are split, instead of being one single coil like on a J-bass, one is constructed ‘reverse wound, reverse polarity’ with respect to the other, the same as a full twin coil guitar or bass humbucker. So you get a single-coil sound but with far less noise pickup.

Because the coils are a bit further from each other compared to the side by side configuration of a standard humbucker, they do pick up a bit more noise when close to a source of noise as the distance allows for a greater variation in the strength of the emitted noise seen by each coil due to the inverse square law. But otherwise they should be fairly hum free. Of course a very cheap pickup might not be constructed properly, so you get two identical coils and hum. But any decent aftermarket or main manufacturer’s P-bass pickup should be fine. Even the cheap ceramic magnet stuck on the back of the pickup types just require the ceramic magnet on one coil to be flipped over and the coils connected correctly to be humbucking.

Well done on getting it working.

Im fairly sure there was a few problems going on with the soldering, very little solder on the tabs, a couple more wires broke away while I was moving the panel around in position for soldering. I went a little extra and used heat shrink to cover any possible shorts. I used the multimeter and checked continuity all is good.

Attachment 44714 I got these guys from Real Tone Music, they are very good now that everything is working correctly I will be doing the fret filing next there is a little fret buzzing but did a bit of truss rod tweaking and adjusted the bridge, very minor buzzing though the action seems a little high now, but Im sure the fret levelling/filing will help to sort that part of out.

Well, after tweaking the truss rod and adjusting the bridge/ intonation, filing the nut and eye balling the neck, I have to say Im very impressed with myself, ran a full test on the tone and volume pots and aside from the guitar being a little heavier than i'm use to, this Bass is sounding sweet as a nut. Solid Bass i'm very surprised at the punch it's delivering I wasn't expecting it. I haven't touched the frets at this point just letting her settle in on a few sessions, seems to be dropping on the lower E string every now and then, which still may be the bridge. All other strings are holding up on tune, I did a full string stretch as these are new strings I had aside for my P bass, and have another set of lights I bought for this, but for now will use the mediums as Im liking the sound. The action is a bit higher than I like but I think thats the frets a couple are sitting up which was causing buzz, but will tend to that in due course.