HemorrhoidWizard Posted June 12, 2016 Share Posted June 12, 2016 (edited) Hello all, I've had a look around at previous posts and I can see stuff similar to my scenario but nothing entirely relevant. If anyone has any ideas, it would massively appreciated. It's a long story so here goes: I purchased a Squier Vintage Modified PJ from Thomann a few weeks back. Beautiful finish and feel. However, the Precision pup would produce no sound unless pushed down in the corner covering the D string. I contacted them and good as gold they sent me a brand new Original '62 Precision Pup to replace the seemingly faulty unit. Once installed, I realised I had the polar opposite problem - my Precision pup was working and sounding great but I now had nothing from my jazz. With some de-solering and some inspection with my meter, I found the Precision pup to be intermittently faulty, jumping around all over the place on the resistance scale where smooth travel would be expected. Ordered 3 new A250k pots and installed 1 to replace the precision which was 90% of the problem resolved. My current problem as follows. Both pickups work and the balance is adjusted by the relevant volume knob (tone fine too). However, if I have both pots at open/100%, there is a big volume drop, almost like a bad ground or phase rejection. Rolling off one of the volumes pots (either) a tiny amount brings the bass back to life. So it's just at 100% volume on both pots where I'm having troubles. I've tried inverting the black and white wires on my Precision pup seemingly made little difference. The height of the pickups are equal/matched at the moment. I'm absolutely stumped. My wiring seems to be spot on (I think) and I checked the new pot before installation. What am I missing here? If it would help, I can upload pictures. Many thanks in advance for any suggestions! Miles Edited June 12, 2016 by HemorrhoidWizard Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted June 12, 2016 Share Posted June 12, 2016 Phase issue? try switching the wires earth/live round on one of the pickups? Quote Link to comment Share on other sites More sharing options...
gjones Posted June 12, 2016 Share Posted June 12, 2016 (edited) I had a similiar problem with my Jazz. I'd resoldered the wires from one of the pickups incorrectly and it had caused the pickups to be out of phase. I swapped them around and the problem was solved. If that isn't your problem, then just Buy a KiOgon wiring loom, with a blend pot instead of the second volume pot and you'll never have to bother with any of that pesky soldering ever again. [url="http://basschat.co.uk/user/7835-kiogon/"]http://basschat.co.u...er/7835-kiogon/[/url] Edited June 12, 2016 by gjones Quote Link to comment Share on other sites More sharing options...
KiOgon Posted June 12, 2016 Share Posted June 12, 2016 Pots & wiring pics please Quote Link to comment Share on other sites More sharing options...
HemorrhoidWizard Posted June 13, 2016 Author Share Posted June 13, 2016 Thanks for the suggestions - I've already swapped my black and white from the Precision Pup to no improved result. I guess I'd achieve the same result reversing the same on the Jazz Pup? I've attached some pictures. Please let me know if you want more specific close ups. Oh and there is a little loose black ground wire off the Precision pup. This was from the original Precision pickup to an eyelet into the body - I snipped this in favour of the large plate on the bottom of the newly installed Precision Pup's - the negative from that plate is now connected to the body of the it's respective volume pot. Hope this shines some light on the potential problem! Thanks again for all the suggestions. Miles Quote Link to comment Share on other sites More sharing options...
Grangur Posted June 16, 2016 Share Posted June 16, 2016 (edited) Looking at the pictures something isn't right. It seems to me that you have both pups wired to the central pot as if you're trying to use it as a blend pot or something. It certainly looks odd to me, unless I'm mistaken that is. The trouble with your pics is we can see the pots and the wires, but we're having to assume a lot in respect of where the wires go. I see you're new here, so "welcome". Have you wired a bass before? Is this your first time? If you're new to bass electrics and want a great drop-in harness, John; Kiogon does a great deal on those. Many folks sing his praises for those. Otherwise I'd suggest that you go back to your wiring diagram and double check it out. Edited June 16, 2016 by Grangur Quote Link to comment Share on other sites More sharing options...
KiOgon Posted June 16, 2016 Share Posted June 16, 2016 Thanks for the mentions guys 3 time I've written a reply then pressed the wrong button. I'll go & have a lie down & some medicine now BTW are they Lindstrom tools in the photo's? Quote Link to comment Share on other sites More sharing options...
HemorrhoidWizard Posted June 23, 2016 Author Share Posted June 23, 2016 Thanks for help so far! What we've got so far is still factory wiring, just with the replacement pickup and 1 250K mini pot audio taper. I thought i'd keep it at that to begin. However, none of the wiring diagrams i've found line up exactly how this is wired. Thank you for the welcome - I am indeed new! I've wired a fair few guitars up before, replacing components, mods etc but never done anything with bass electrics. Getting inside this one, it looks like a very unusual way to wire up pots and pups but maybe not! I tried inverting the phase on the pickups again. Result: Precision massively quieter than the jazz. So how I had it originally was closer where both pups would work standalone. I also tried switching the cap so the leg went to the outer of the pot, rather than the central lug (obviously swapped the signal wire to the other pot too). Result: Precision worked great, no jazz signal at all. I've wired it all back to how it was in my first message. Rather than faff with pictures i've sketched up a crude wiring diagram. Compared to [url="http://members.ziggo.nl/s.k.wiersma/images_bass_building/Wiring%20diagram%20-%20std_p_j_bass.jpg"]this diagram[/url], I can see some differences but to my eye nothing massively wrong...however, i'm so far from a professional it's laughable! Anyway, I'll cut to the chase - thought i'd throw the two diagrams on here and see if you guys see anything! Next plan is to rip apart all existing wiring and start a fresh with new wiring (getting rid of that nasty multicore thing thats in there too!) John, I'm curious about your drop-in harnesses - you may well be hearing from me depending on how this goes and yes, Lindstrom tools! Both my Mom and Uncle we're at BT circa 1970~1980 and I believe they were standard issue. We've a fair few pairs of pliers and cutters around and they are really brilliant, even after all this time! Quote Link to comment Share on other sites More sharing options...
LITTLEWING Posted June 25, 2016 Share Posted June 25, 2016 Follow the normal standard wiring diagram exactly but swap the Jazz (bridge) pup wires so that the coloured wire goes to the back of the volume pot casing and the black goes to the centre volume pot peg. All will burst back into life in every volume scenario. I had the same problem with my PJ when I replaced the bridge pup and had the same duff sound with both volumes full on. Something to do with phase blah blah.... Quote Link to comment Share on other sites More sharing options...
BassBunny Posted June 26, 2016 Share Posted June 26, 2016 (edited) The Seymour Duncan diagram is one I have used a number of times and is pretty standard. Your version is pretty much the same but they have overcomplicated it using the multi-core. If it were me I'd start from scratch, rewire as per the SD diagram and go from there. Edited June 26, 2016 by BassBunny Quote Link to comment Share on other sites More sharing options...
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