fleabag Posted October 19, 2016 Share Posted October 19, 2016 (edited) This is a strange one I simply changed the pickup covers on my bass, and never touched anything else. Pup screws out, new cover on, screws back in. I have now lost a rather significant amount of volume from the bridge pickup. So much so, that i've now screwed the neck pickup down virtually flat to the body, and the bridge raised to nearly meet the strings, and the difference is still vast. Pretty much all the bottom end has disappeared from bridge pickup, so i have to wind up the bass tone to full, but its still lacking what it used to have. But having done that, as soon as i use the blend knob to go fully to the neck pickup, the volume and bass overwhelms to a huge extent. Its not like there's no volume in the bridge pickup. Its just that before i changed the covers, the pickups were fairly balanced in output, and i didnt have to make such large adjustments with the bass control when going from bridge to neck. I havent a clue why this would have happened. I did check the wiring, but if i'd accidently knocked a connection off, surely there would be no volume at all from the bridge ? Edited October 19, 2016 by fleabag Quote Link to comment Share on other sites More sharing options...
fleabag Posted October 19, 2016 Author Share Posted October 19, 2016 Its worth adding, as i had forgotten, that its 5 knob active - stacked vol / overall tone ... balance ... treble.. stacked mid freq / vol ... bass Quote Link to comment Share on other sites More sharing options...
Norris Posted October 19, 2016 Share Posted October 19, 2016 (edited) Could you have shorted out a few of the coils when you changed the covers? Fewer (effective) coils would mean less output. Does it improve if you refit the old cover? Edit: Or it could be a dodgy solder joint if you've played with it or disturbed it Edited October 19, 2016 by Norris Quote Link to comment Share on other sites More sharing options...
fleabag Posted October 19, 2016 Author Share Posted October 19, 2016 I did check wiring, but there's no problems there. Well not that i can see. They're just plastic jazz covers so just changing them wouldnt have an affect. The pots are not normal though. They have square bases. Just wondering if one of them has a problem Quote Link to comment Share on other sites More sharing options...
fleabag Posted October 19, 2016 Author Share Posted October 19, 2016 (edited) Small update The blend pot seems odd. Starting with the neck pickup on full and then gradually rolling the blend pot to half way between both pickups, ( there's an indent to know where halfway is ) there's no difference whatsoever in tone or volume. None Its like the neck pickup is still on full. Its only when the blend is right back onto the bridge pickup, does all the vol and bottom end drop right off. This is not how it was the day before, so i'm sort of leaning towards that as the problem. If it was that, i wouldn't know what to order, so its looking like guitar tech time Edited October 19, 2016 by fleabag Quote Link to comment Share on other sites More sharing options...
brensabre79 Posted October 20, 2016 Share Posted October 20, 2016 Re: blend pot. It's normal for the neck pickup to be on full all the way to the centre position, then as you move toward bridge pickup from there the neck pickup should roll off. You're probably noticing it more as your BridgePU seems quiet. It may be coincidence, but as you've tinkered with the BPU and it's now quieter, I'd start with that. You could have just disconnected the earth, or if the bass is shielded (either with copper or black shielding paint) you could be catching the shield with one or more wires. That would be the easy fix. As mentioned, it's incredibly easy to catch the coil windings when you take the cover off, even if you can't see any obvious physical damage there may be some. Unfortunately that is a worst case scenario so it's best to rule it out early... So the first thing to do is get hold of a multimeter (they are about £10 and well worth it!). Check the impedence of both pickups: This is best done without the pickups connected to the preamp Set the multimeter to kΩ and measure using the two wires coming from the pickup. Every pickup will be slightly different, but they should both be in the same ball park (e.g. 8kΩ - 10kΩ... 10 - 12... etc.) Active pickups tend to be much lower than passive ones. Normally it would tend to be slightly higher or the same. If they are about the same, it's a safe bet your pickup is OK. (I hope it is). If your BPU is significantly lower than the NPU then you've probably damaged the coil winding, and depending on the pickup it's a professional repair or replacement in that case. You can also use the multimeter to check the rest of the wiring. Quote Link to comment Share on other sites More sharing options...
fleabag Posted October 20, 2016 Author Share Posted October 20, 2016 Thanks for that info I have a multi meter so i'll check both pups and see what they read. I'm wondering though, if i'd damaged the BPU wiring, why there is any output at all. Its not like there's none. Its just gone a lot quieter, in a very noticable way Quote Link to comment Share on other sites More sharing options...
fleabag Posted October 20, 2016 Author Share Posted October 20, 2016 Ok ! Neck pup = 7.88 on the 20k ohm setting Bridge pup = 1. which is the default for when the MM connectors are not connected to anything but MM is switched on So i guess the BPU is foobarred. Bo**ocks ! Quote Link to comment Share on other sites More sharing options...
mcnach Posted October 20, 2016 Share Posted October 20, 2016 [quote name='fleabag' timestamp='1476960497' post='3158793'] Ok ! Neck pup = 7.88 on the 20k ohm setting Bridge pup = 1. which is the default for when the MM connectors are not connected to anything but MM is switched on So i guess the BPU is foobarred. Bo**ocks ! [/quote] Something like that happened in a jazz I used to have, but by itself. Upon close examination I found the wire had broken halfway somehow... there was still output but a lot weaker. Sometimes what happens is not that it breaks but that the little blobs of solder where teh wire goes, on the pickup, is damaged. It may look fine but it can have a fracture... just touch the solder briefly with the tip of a solder iron: if it's a solder issue it'll fix it. It happens rarely but it's easy to try... Quote Link to comment Share on other sites More sharing options...
fleabag Posted October 20, 2016 Author Share Posted October 20, 2016 Good speech Mac Worth a shot. Apart from that , who can sort the pickup if i cant ? Any recommendations chaps ? Quote Link to comment Share on other sites More sharing options...
mcnach Posted October 20, 2016 Share Posted October 20, 2016 [quote name='fleabag' timestamp='1476966880' post='3158868'] Good speech Mac Worth a shot. Apart from that , who can sort the pickup if i cant ? Any recommendations chaps ? [/quote] What pickup brand is it? Mine was a Nordstrand. I was actually posting about it on TalkBass and someone from Nordstrand contacted me directly. They asked me to send them the pickup and they rewound it to original specs free of charge. So in some cases contacting the manufacturer could give good results: even if they charge something, it'll be restored to the original specs for sure. Quote Link to comment Share on other sites More sharing options...
fleabag Posted October 20, 2016 Author Share Posted October 20, 2016 Its a Sire V7 Marcus Miller, so its either their own brand, or made for them. Unfortunately, that means i have no idea. I guess Sires are built abroad somewhere so that would sort of be out of the question. I guess i'm looking at UK pickup makers and see if they can do the job. Quote Link to comment Share on other sites More sharing options...
fleabag Posted October 20, 2016 Author Share Posted October 20, 2016 Decided not to mess with it, and send it to a pro. Found Hotrod Pickups on here and phoned Dave Walsh - he even described the problem before i did To think i did this because i simply changed the pickup covers is annoying, but hey ho Quote Link to comment Share on other sites More sharing options...
brensabre79 Posted October 20, 2016 Share Posted October 20, 2016 Sorry to her that. Sounds like you were unlucky, but glad you're getting it sorted. I was going to recommend Hot Rod, so you should be in safe hands there Quote Link to comment Share on other sites More sharing options...
fleabag Posted October 20, 2016 Author Share Posted October 20, 2016 (edited) My own fault ! Yup, Dave at Hotrod answered the phone immediately and was very pleasant to talk to. He was recommended on BC , as i did a search for pickup winders here on BC and noticed that he's actually posted on here too. Problem solved Edited October 20, 2016 by fleabag Quote Link to comment Share on other sites More sharing options...
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