Jump to content
Dankology

Pickups - please help an idiot out

Recommended Posts

I'll try and keep this short.

I recently picked up a second hand Relvelation PJ with a known issue with the pickups. On playing it, it seemed that both the P and J pickups were fine on their own but when set at the same volume (ie both full open), the D and G strings became very tinny.

I'd already ordered a new loom from Kiogan of this parish and had hoped that installing this it would rectify any dodgy wiring issues. Sadly the D and G issue remained. I tried swapping the white and black wires from the P around but by the time I tested this, the P pickup on its own now had a huge volume difference between the E/A and the D/G.

So I suspect I've broken (or at least finished off) the half of the P pickup that covers the higher two strings.

I was looking to replace it like for like as I really quite liked what little I heard of the Entwistle PBXN before killing it.

So, two questions, please:

1) is there anything else I can do or check before replacing the pickup?

2) if I do replace it, can I save a couple of quid by buying the standard PBX pickup and swapping in the neodymium magnets from the existing pickup?

Share this post


Link to post
Share on other sites

Depending on how tinny, either one of your pickups is out of phase (either the coil is wound the wrong way, the pickup is in backwards or the lead is reversed), or its a feature of the bass.

I would just swap the wires from one of the pickups round and try again

  • Like 1

Share this post


Link to post
Share on other sites
1 minute ago, Woodinblack said:

Depending on how tinny, either one of your pickups is out of phase (either the coil is wound the wrong way, the pickup is in backwards or the lead is reversed), or its a feature of the bass.

I would just swap the wires from one of the pickups round and try again

But it's definitely got worse since I started fiddling with it - there was no volume difference when the P pickup was soloed before which makes me think I've possibly damaged the coil while tinkering.

I forgot to mention as well - when both volume pots are turned all the way down there is still some output...

Share this post


Link to post
Share on other sites
14 minutes ago, Dankology said:

But it's definitely got worse since I started fiddling with it - there was no volume difference when the P pickup was soloed before which makes me think I've possibly damaged the coil while tinkering.

If it is louder (much louder) when either pickup is solo than when both are present, it is out of phase - there can be a slight drop in volume when they are both up, but not to the point where it is problem.

14 minutes ago, Dankology said:

I forgot to mention as well - when both volume pots are turned all the way down there is still some output...

That indicates that you don't have an earth on your volume, and thus probably your pickups, and that would cause lots of trouble.

Ensure that there is a continuity at all times between the sleeve of the jack socket, one pin of the volume, one pin of the tone and one side of each pickup.

Actually, what are the controls on this? Is it volume volume tone, or volume balance tone? If it is VVT, the pickups should be entirely shorted out when the volume is down. so check that too.

I am making an assuming this is passive - tell me if this is wrong

Share this post


Link to post
Share on other sites
8 minutes ago, Woodinblack said:

If it is louder (much louder) when either pickup is solo than when both are present, it is out of phase - there can be a slight drop in volume when they are both up, but not to the point where it is problem.

Thank you for taking the time - really appreciate this: first day of a much needed holiday and I really didn't intend spending it repeatedly taking a bass apart.

It's passive with a VVT layout. The earth seemed well-anchored under the bridge and the continuity you describe above seems intact.

I've just taken the P pick up out and run a multimeter across it: 8.4ohm across the two units and 4.1 when each is checked individually. This means almost nothing to me but it seemed promising that there wasn't a huge discrepancy between the two.

Share this post


Link to post
Share on other sites
35 minutes ago, Dankology said:

Thank you for taking the time - really appreciate this: first day of a much needed holiday and I really didn't intend spending it repeatedly taking a bass apart.

Maybe leave it for now and enjoy your holiday for a bit while just playing on one pickup?

35 minutes ago, Dankology said:

It's passive with a VVT layout. The earth seemed well-anchored under the bridge and the continuity you describe above seems intact.

I've just taken the P pick up out and run a multimeter across it: 8.4ohm across the two units and 4.1 when each is checked individually. This means almost nothing to me but it seemed promising that there wasn't a huge discrepancy between the two.

I am hoping your read them wrong and it is 8.4k rather than 8.4 ohm or you have a piece of wire!

OK, so each pickup is shorted out when its respective volume is completely off?

If so you shouldn't be able to hear anything when both volumes are off

Share this post


Link to post
Share on other sites
11 minutes ago, Woodinblack said:

Maybe leave it for now and enjoy your holiday for a bit while just playing on one pickup?

I am hoping your read them wrong and it is 8.4k rather than 8.4 ohm or you have a piece of wire!

OK, so each pickup is shorted out when its respective volume is completely off?

If so you shouldn't be able to hear anything when both volumes are off

Ha, if I tried to ignore it and do something else it would just eat away at me until I went back to it...

Apologies re the units - showing how little I remember from school there 😣

I've wired everything back together and all seems well apart from there still being output from the P pickup when its volume is completely off.

I can live with this but it's still annoying. When you talk about the pickups being shorted out when the bolume is turned down - how would I test this?

Share this post


Link to post
Share on other sites
4 minutes ago, itu said:

Pictures, please. They might give some hints on the issue.

Here are photos of the original wiring, the very tidy new loom from KiOgon and then the back of the problem pick up.

20201019_112914.jpg

20201019_151232.jpg

20201019_151216.jpg

Share this post


Link to post
Share on other sites
10 minutes ago, Dankology said:

Apologies re the units - showing how little I remember from school there 😣

I've wired everything back together and all seems well apart from there still being output from the P pickup when its volume is completely off.

I can live with this but it's still annoying. When you talk about the pickups being shorted out when the bolume is turned down - how would I test this?

When you have a VVT on a fender style control (as opposed to a gibson type control which is the other way), the pickup is shorted to ground by the volume control to stop it contributing,

So if you put your meter on the black and white leads on that P pickup, which as you have said is measuring 8.4K. As you turn the volume down that number should go down to 0 when it is fully down.

Same with the J pickup and the other volume.

Share this post


Link to post
Share on other sites
10 minutes ago, Woodinblack said:

When you have a VVT on a fender style control (as opposed to a gibson type control which is the other way), the pickup is shorted to ground by the volume control to stop it contributing,

So if you put your meter on the black and white leads on that P pickup, which as you have said is measuring 8.4K. As you turn the volume down that number should go down to 0 when it is fully down.

Same with the J pickup and the other volume.

The J goes down to zero when the volume pot is down but the P goes from 7.9 wide open to 8.1 fully closed.

Which I'm guessing is not right.

Share this post


Link to post
Share on other sites
9 minutes ago, Dankology said:

The J goes down to zero when the volume pot is down but the P goes from 7.9 wide open to 8.1 fully closed.

Which I'm guessing is not right.

No, that is not right. If it is wired correctly, the volume control should short it out completely. The J is right, the P volume is wrong, or somehow not connected

 

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Recently Browsing   0 members

    No registered users viewing this page.



×
×
  • Create New...