Pickups way too unbalanced!

[waltschwarzkopf]

Re: Pickups way too unbalanced!

That suggests both pickups were either damaged when removing the covers or were faulty, to begin with.

Ok. Since I didn't measure the DCR nor output before removing the covers, if we assume that they were faulty, to begin with, then that is the end of the story and it's my fault for not remembering. I do remember that when I took this guitar to practice the neck pickup was too bassy and I had to change to the bridge, but I don't remember if there was such a volume difference

Now, let's assume that I damaged then while removing the covers. How did this happen? The wiring seems fine, the switch is continuous where it should, I get output (similar mV on both pickups), I can measure the DCR (although the values are weird), and both pickups make a sound, just that one is way louder and hence the purpose of this post.

IF I had damaged BOTH of them, the values would be as they are now, but the volume would be similar for both too.

IF I had damaged ONLY the neck, the volume would be as it is now, but the bridge would measure out fine, both DCR and mV.

It seems that I didn't pull the cables to much to mess the wiring up since everything else is still connected. This is what I did:

1. Remove the strings
2. Remove the neck pickup
3. Remove ring
4. Remove the cover
5. Remove the excess wax
6. Install the ring back
7. Mount the pickup
8. Repeat 2-7 for the bridge pickup
9. Restring the guitar.

I was very careful throughout the process. But, let's say that I destroyed one (or more) of the bobbin's winding and opened the circuit, then the pickup(s) wouldn't sound or there would be no output. Let's say that I shorted one of the bobbins, then the DCR would be ZERO or very low and also there would be no output.

The only option that can think of, and it's also the simplest, is that when I reinstalled the pickups and READJUSTED the height I did it right/wrong AND much different than it was before. This would explain why after my "setup" the volume is so different and the measured output (mV) is 50% greater for the bridge. And also, after lowering the bridge pickup as low as possible, the difference is output is about 15%, which I guess it's fine. I'm really curious to get home and see how it sounds now.

The output jack measurements of 400kOhm are crap, but I have seen them before in Epiphones. I remember rewiring a LP Custom and a LP Trad Pro, with the exact same configuration and one your measure 8kOhm at vol10 and 0 at vol0, while the other measured 450kOhm at vol10 and 0 at vol0. This drove me crazy for hours, I was reckeching everything, unsoldering and resoldering, until I gave up and went to bet at 3am. New day I plugged in the guitars and both worked fine, jus that the "weird" one had less volume than the other. However, since both guitars had "calibrated" pairs (also by Epiphone) I didn't bother to waste any more time.

Looking forward to your comments!

 

[Wattage]

Re: Pickups way too unbalanced!

Still curious as to how you removed the wax?

 

[gregory]

Re: Pickups way too unbalanced!

I'm thinking damage may have been done to the connections between the cable and the internals of the pickup.

If you measure the resistance between the outer lugs of each volume control with the switch not in the center connection, you will get values slightly lower than the DCR of each pickup. It will be like 7k or 13k, not be 400k, unless there is a blocking cap inside the pickups which will not be the case here.

As for the voltage measurements they are simply to low to serve much use beyond neither pickup is providing anywhere near the amount of output that it should.

There is more than one way to damage a pickup that doesn't necessarily result in either a short or an open circuit. With a true short or true open you would get no output, but you do get at least something. The tonality of the pickups can provide a clue.

It is clear to me the problem is upstream from the volume controls since you verified that the switch and jack and all the wiring connecting them is fine from at least a DC perspective. What isn't known from a DC perspective is whether the tone pots are causing a problem. I very much doubt this to be the case unless you have them on zero which still doesn't explain your inability to measure the resistances of the pickups.

 

[gregory]

Re: Pickups way too unbalanced!

Also, did you check continuity between ground and each of the baseplates?

 

[waltschwarzkopf]

Re: Pickups way too unbalanced!

Also, did you check continuity between ground and each of the baseplates?

I did not do that, I’ll give it a try tomorrow. Regarding the hum, there is a low pitched hum on the neck, quite weak. The bridge has a higher pitched hum that is a bit louder.

I do have some news!

Now the pickups are balanced in volume, but the bridge is very muddy. I don’t know if that is because Epis are usually mud-buckers or if it is because it is too low. I may rise the bridge a tiny bit, to make the sound clearer and slightly louder than the neck. The effect of the magnet and DCR of the pickup was also apparent, as the neck was warmer and cleaner than the bridge.

I noticed something else, rolling off the tone decreases the volume considerably and also takes a lot of the gain out. It is the first time that I see something like this.

I tried this on my SS practice amp and through headphones, to be quite sure of what I was hearing and how loud it was.


Sent from my iPhone using Tapatalk

 

[Chistopher]

Re: Pickups way too unbalanced!

Loss of volume due to rolling the tone back is one of the many reasons I don't use 50s wiring, but I really don't think that's the culprit. At this point I'd just do a complete rewire with quality components. If the problem persists you might as well buy new pickups.

 

[gregory]

Re: Pickups way too unbalanced!

He isn't using '50s wiring and it's pretty obvious the volume pots and wiring between the volume pots and jack (IOW all the wiring besides the leads from the pickup) are not the culprit.

 

[Aceman]

Re: Pickups way too unbalanced!

Congratulations guys - way to keep it classy. No wonder the cool people frequent this place less and less. Some of you guys need to man up, inflate your tiny little nuts to big boy size and apologize to the OP.

Dear Mods - Yeah - I'm talking to you - yet another example of individual posts that could be nuked, and strong personal messages sent. Yet crickets. Nice job on your part too.

For those providing real advice and insight, thank you for representing.

OP - hang in there. We'll get it worked out.

 

[beaubrummels]

Re: Pickups way too unbalanced!

Yeah, that's what I changed them. I realized that at home where I regulate "gain" with the vol pot, I prefer LOG. Whereas at the studio where I use the vol to regulate "volume" I prefer LIN.

Anyways, I measured the pickups again, and got this:


Neck pickup Vol 10 at the jack: 421kOhm
Neck pickup Vol 10 at the pot: 468.7kOhm
Bridge pickup Vol 10 at the jack: 439kOhm
Bridge pickup Vol 10 at the pot: 488.5kOhm

For some reason, these values are not exactly the same as the ones posted above. I realized that when measuring at the jack the DCR fluctuates a lot and the values are shown now are a few seconds after I allowed it to stabilize. On the other hand, the DCR at the pot stabilizes instantly.

Those aren't pickup measurements. You're only measuring the pot value.

 

[waltschwarzkopf]

Re: Pickups way too unbalanced!

He isn't using '50s wiring and it's pretty obvious the volume pots and wiring between the volume pots and jack (IOW all the wiring besides the leads from the pickup) are not the culprit.

Correct, the guitar has its original wiring, which is "modern" style. The tone removes a LOT of the volume, drastically decoming quieter and cleaner. I'll see if I can make a demo and post it so you know exactly what I'm dealing with. I've had 50's wiring on other guitars and I did not experience such a volume loss. This leads me to think that the tone pots are losing too much signal to the ground. I'll try changing the capacitors and rewiring everything in the same way but with new cables.

Still curious as to how you removed the wax?

I carefully scraped the wax off the pickup. I did not apply force nor heat, I didn't scratch the plastics, nor plate, and the tape on the sides is still in the right place and was not even lifted! It goes without saying, but the wires connecting both bobbings were not touched at all and the winding was not even visible, so it very unlinkely that I messed them up. The possibility is that the connection between the bobins and the pickups lead is messed, just like grgora says.

Those aren't pickup measurements. You're only measuring the pot value.

When measuring directly on the pot, I agree because the pickups are wired to the pots. But when measuring directly at the output jack using a mono plug wired to a multimeter, it should read the DCR of the pickups (or close) at vol10. This does work with other guitars, and like I said, it is not the first time that I see this strange behaviour on an Epiphone.

 

[Aceman]

Re: Pickups way too unbalanced!

50's wiring should be THE standard. They got it right the first time.

 

[Chistopher]

Re: Pickups way too unbalanced!

I carefully scraped the wax off the pickup. I did not apply force nor heat, I didn't scratch the plastics, nor plate, and the tape on the sides is still in the right place and was not even lifted! It goes without saying, but the wires connecting both bobbings were not touched at all and the winding was not even visible, so it very unlinkely that I messed them up. The possibility is that the connection between the bobins and the pickups lead is messed, just like grgora says.

Scraping the wax off the pickup does little to affect the tone. If you want to have an audible change you have to find a way to remove the wax from the inner coils.

 

[waltschwarzkopf]

Re: Pickups way too unbalanced!

Scraping the wax off the pickup does little to affect the tone. If you want to have an audible change you have to find a way to remove the wax from the inner coils.

I only did it because I didn't want a huge block of wax over and around the coils. That is why they are called "waxbuckers", if you remove the cover you find exactly what I described, so I removed the excess wax so it would look good. I did think about "unpotting" the pickup and removing all the wax by heating it up, buzt I was afraid to mess it up and damage the pickup.

 

[waltschwarzkopf]

Re: Pickups way too unbalanced!

50's wiring should be THE standard. They got it right the first time.

Right! I also think it rocks, that and LOG pots for the volume AND tone. So far that is my favorite configuration.

 

[gregory]

Re: Pickups way too unbalanced!

The tone pots would have to be less than ~200k before they starts dumping volume.

Did you measure the DCR between the lug connected to the cap and the lug connected to the lead coming from the volume control when the pot is at 10?

Have you disconnected the pickups and measured their DCR?

 

[Wattage]

Re: Pickups way too unbalanced!

Have you re-hit all the connections with the soldering iron?

I use a hairdryer to get rid of the wax, makes it quick and easy

 

[waltschwarzkopf]

Re: Pickups way too unbalanced!

The tone pots would have to be less than ~200k before they starts dumping volume.

Did you measure the DCR between the lug connected to the cap and the lug connected to the lead coming from the volume control when the pot is at 10?

Have you disconnected the pickups and measured their DCR?

No and no. I will try to unsolder everything this weekend and measure resistance on all components and rewire everything using new cables; I'll even try to change the wires of the pickup themselves.

Have you re-hit all the connections with the soldering iron?

I use a hairdryer to get rid of the wax, makes it quick and easy

Also no. I'll do what I said above and see it now it works. I thought about using a hairdryer, but I didn't have one at the moment. Any other way to remove the wax without a hair dryer? If I heat the plate with the soldering iron, will I damage the coils?

 

[gregory]

Re: Pickups way too unbalanced!

If the tone control is >200k (I'm intentionally being this generous) then it is not the culprit. Even if the cap is bad, it cannot be the culprit, either.

If the tone pot checks out then the only wiring that could possibly be at fault is what is connected between the volume control and the pickups. Everything else has been verified to be in working order, which includes connections you have not probed.

Trying to fix what isn't broken can only serve to make your current situation worse.

 

[waltschwarzkopf]

Re: Pickups way too unbalanced!

If the tone control is >200k (I'm intentionally being this generous) then it is not the culprit. Even if the cap is bad, it cannot be the culprit, either.

But if the cap were faulty and now has some sort of continuity at all frequencies, wouldn't it work as a second volume?

The only wiring that could possibly be at fault is what is connected between the volume control and the pickups.

The I should start by removing the pickups and measuring DCR there. And if it's wrong, change the cable; if it's right, leave as is and look elsewhere.


I think the problem is on those Epi volume pots, I've seen this issue in the past with Epi guitars.

 

[gregory]

Re: Pickups way too unbalanced!

Also no. I'll do what I said above and see it now it works. I thought about using a hairdryer, but I didn't have one at the moment. Any other way to remove the wax without a hair dryer? If I heat the plate with the soldering iron, will I damage the coils?

You might want to make it clear whether you want *all* the wax removed. Some may be under the impression that you want it gone even between the windings.

Could heating the pickups be the reason you're having a problem? Yes. Is it only the windings that could have been affected? No.