Humming like guitar isn't plugged in

[Phil66]

Hello all,
I have just had some new humbuckers fitted into my Epiphone Les Paul, (see Warman Guitars ) . They sound great but if I turn the volume pots down and the tone pots up I get the same sound from my amp as if I have pulled the lead from my guitar All of the earthing has been checked out to be ok.

Any ideas? I tried 4 of my other guitars through the exact same amp, same pot settings and I only get the "amp switched on" sound.

Phil

[big_teee]

Hello all,
I have just had some new humbuckers fitted into my Epiphone Les Paul, (see Warman Guitars ) . They sound great but if I turn the volume pots down and the tone pots up I get the same sound from my amp as if I have pulled the lead from my guitar All of the earthing has been checked out to be ok.

Any ideas? I tried 4 of my other guitars through the exact same amp, same pot settings and I only get the "amp switched on" sound.


Phil

You might try checking to see if it wired anything like this diagram.
Wiring Diagram
Good Luck,
Terry

[Phil66]

Thanks for that, everything appears in order. Both my guitar tech AND the pickup manufacturer have not had this prob before :/

Phil

[big_teee]

Thanks for that, everything appears in order. Both my guitar tech AND the pickup manufacturer have not had this prob before :/

Phil

Can you take some Gut shot Pictures we could look at for the Hell of It?
Do you have a soldering Iron?
I would try taking the Cap loose on one end?
Does this happen on both tone circuits?
So if you pick the bridge with selector switch, then when you turn up the tone on the bridge you get the noise?
And same way with the neck selected, and same with both selected?
Strange.
Are these 4 wire or 2 wire pickups?
Terry
Edit Note*
I just read your post again.
So if you turn your volume down it should short the output jack to ground.
It sounds like the volume Pots are not grounded.
When you turn down the volume to zero.
It's the same as shorting the plug output to ground.
If you look at the diagram one side of the volume pot has to be grounded to the Pot Ground.
Once you short this out, It would not matter what you do on the Tone Pot!
Check that and tell us what you find!

[Phil66]

Here is a pic as requested. I don't have a clue with the terminology of electronics but if you tell where to put a test wire I'll have a go.


Cheers

Phil

[big_teee]

Here is a pic as requested. I don't have a clue with the terminology of electronics but if you tell where to put a test wire I'll have a go.


Cheers

Phil

Phil
I can't see under the white tubing is the 3rd leg of the volume pots bent over and grounded?
Do you have a Mult Meter with Ohms scale on it?
I can tell you how to test it!
T

[big_teee]

If you have a Multi Meter that reads ohms, this is how to check to see if your Vol. Pots are working right.
Plug guitar cord into your guitar, No Amp.
Put selector switch on Neck Pickup.
Open vol Pot to Full Volume.
Check your guitar cord. Put one meter probe on Shield ground side and touch the other probe to the tip of plug.
Set your meter to Ohms and turn the scale so you can read at least 10-20k Ohms.
It should read around 7-8k Ohms.
Turn the volume off to no volume.
Now read the guitar cord again, and it should be a short circuit Zero Ohms.
Turn Selector Switch to Bridge Pickup, and repeat above.
You should read between 7.5-16k Ohms, depending on the pickups.
I suspect you will not read zero ohms with vol. pots turned off.
Let us know what you find.
Thanks
Terry

[jmaf]

You're missing a ground somewhere.

I was unable to zoom in on the picture but I only see one white lead coming from the jack. You should have a black lead coming from there as well, pardon if there already is one, on my monitor the image wasn't really clear.

[Phil66]

Just done a bit of a test, I put some rag under the strings to stop them making any sound, I then switched the amp on with the guitar connected. As I turned the volume up the humming got quieter the more I turned up the volume.

I'll try to put some better pics on this weekend.

Phil

[spud1950]

Why aren't you insisting that your "tech" take the responsibility for correcting this problem? If the guitar was functioning properly before he did his work,then obviously he did something wrong. You payed him to install the pickups and you have the right to expect everything to work properly.He needs to either correct the problem or give your money back if he's incapable of doing so.

[big_teee]

[QUOTE=spud1950;210369]Why aren't you insisting that your "tech" take the responsibility for correcting this problem? If the guitar was functioning properly before he did his work,then obviously he did something wrong. You payed him to install the pickups and you have the right to expect everything to work properly.He needs to either correct the problem or give your money back if he's incapable of doing so.[/QUOTE


Who Knows?
They may not be in the same place?
Doesn't sound like much wrong, I could isolate it in a few minutes, If I could get a hold of it.
Hard to work on Miles away on the forum! lol
Terry

[Phil66]

Well, the tech has offered to replace the original pickups FOC. I really don't know if the problem was there before the change over.

My local shop has been totally honest and is willing to sort it out at ground level, can't say fairer than that eh??????



;o)

[big_teee]

That's fair enough, but I bet you can fix it.
Hang in there.
Later,
T

[Phil66]

I have spoken to the person that makes the pickups, he is adament that it is a bad earth leak. Especially after I told him that the humming fades as you turn the volume up.

Taking it back to shop tomorrow, they will sort it, it's just that they have never come across it before so it a bit of clutching at straws.

Phil

[Phil66]

Ok, took it into the shop today, we put it through one of Steve Vai's Legacy amps, one of the actual ones he used on his tour, they are the only UK Carvin dealer, that's how they got it.
Ok, there just isn't the same problem in the shop. I'm taking my amp in tomorrow, it's something very strange and we are all scratching our heads.

Phil