EMG noisy

[Co0lCat]

In 2011 I bought brand new a LTD EC-1000D, it came with a quick connect 81/60 EMG set soldered to the controls. I recently unplugged the 81/60 set and just plugged in a 57/66 set, but it's really noisy and hums...I use ENGL tube amps. I have a 94 Gibson SG with 81/85 set and it's not humming or noisy, neither is my LTD MH-250 with 81/H set, I have a 98 Les Paul with old DiMarzio Distortion 2's in it and it's not noisy at all. I don't understand this, I didn't disturb the cavity control, I didn't have to because all I did was remove the pups from the top unplugged them and then just plugged in the new EMGS...(yes properly I double checked).
What could be causing this?
I have some left over EMG quick connect parts to replace all the controls in the EC, would this help? I notice that my soldered setup is like any other with a capacitor on the tone pot, but there is a tiny integrated cap on the tone quick connect...could this be why?
I haven't changed out the parts yet because I want some input.

[Co0lCat]

i think this is a ground loop!

[curtisa]

It won't be a ground loop.

Can you confirm that you have the quick connect on the back of each pickup terminated the right way around?

What happens if you temporarily run a wire from the back of one of the pots to the strings?

[Co0lCat]

2 hours ago, curtisa said:

It won't be a ground loop.

Can you confirm that you have the quick connect on the back of each pickup terminated the right way around?

What happens if you temporarily run a wire from the back of one of the pots to the strings?

yes of course double checked....not sure if they made it so you can't do this, but before quick connects, if you soldered them in wrong you could ruin the preamp in the pickup.,..but I didn't do that, I've swapped out EMGs in my other guitars but they don't make this humming...I removed the black wire from the master tone pot to the two volumes because that was redundant as everything is already grounded through the controls, which proved to be correct after I removed them and checked for the ground continuity on all the controls which was all good....I wonder why they added the extra ground wire, surely I thought this was the ground loop, and it very well may have been part of it...so I removed them but I still have some hum...

[Co0lCat]

4 hours ago, curtisa said:

It won't be a ground loop.

Can you confirm that you have the quick connect on the back of each pickup terminated the right way around?

What happens if you temporarily run a wire from the back of one of the pots to the strings?

I didn't read that last part right... that does nothing, but since I removed those redundant ground wires only the bridge pickup is making the hum now. I'm going to swap the bridge and neck tomorrow to see if it's the bridge pickup that bad...which would be a first in my over 40 years of using EMGs

[curtisa]

1 hour ago, Co0lCat said:

but before quick connects, if you soldered them in wrong you could ruin the preamp in the pickup

The EMG pickup typically includes internal protection to prevent reverse-polarity from damaging anything (it's still relatively easy to install the battery back to front in many guitars. EMG will be aware of this and will have designed their pickups to withstand such an error). From memory the quick connector is not polarised and can be installed either way up on the pickup, hence my query. But if you've discounted that then all good.

1 hour ago, Co0lCat said:

I removed the black wire from the master tone pot to the two volumes

Which black wire? This one (with the red dash)?:

 

Quote

because that was redundant as everything is already grounded through the controls, which proved to be correct after I removed them and checked for the ground continuity on all the controls which was all good

If you've removed the ground wire indicated you're probably still getting continuity via the pot cases being secured to the black conductive paint inside the cavity. That isn't the source of a ground loop though, and the wire will have been specifically run to ensure that the ground continuity between the various points in the circuit remains constant and secure. With the indicated ground wire removed, if the nut on the tone pot became loose you'd end up with pickups that can hum and buzz as the ground connection makes and breaks intermittently in sympathy with the loose tone pot. Even the higher resistance of the black paint compared to a direct wire might be enough to cause hum issues.

[Co0lCat]

29 minutes ago, curtisa said:

The EMG pickup typically includes internal protection to prevent reverse-polarity from damaging anything (it's still relatively easy to install the battery back to front in many guitars. EMG will be aware of this and will have designed their pickups to withstand such an error). From memory the quick connector is not polarised and can be installed either way up on the pickup, hence my query. But if you've discounted that then all good.

Which black wire? This one (with the red dash)?:

 

If you've removed the ground wire indicated you're probably still getting continuity via the pot cases being secured to the black conductive paint inside the cavity. That isn't the source of a ground loop though, and the wire will have been specifically run to ensure that the ground continuity between the various points in the circuit remains constant and secure. With the indicated ground wire removed, if the nut on the tone pot became loose you'd end up with pickups that can hum and buzz as the ground connection makes and breaks intermittently in sympathy with the loose tone pot. Even the higher resistance of the black paint compared to a direct wire might be enough to cause hum issues.

yes that wire...it's connected through the ground on all the pups and 3 way switch, I had already thought about the paint...I'm starting to think it's a bad pickup wince the neck pup is not humming now. tomorrow I'm swapping them out, if it hums in the neck position then it's the pickup and I'm just buying a new one...weird, as I stated I've used EMGs for 50 years I've never had one go bad before

Edited September 10, 2020 by Co0lCat

[curtisa]

Here's another experiment to try: what if you unbolt all three pots and lift them out of the cavity so that the cases no longer make contact with the shielding paint - does it still hum? Note that you'll have to temporarily reinstall the black ground wire you removed between the tone pot and the middle volume pot in order to perform this test.

[Co0lCat]

7 hours ago, curtisa said:

Here's another experiment to try: what if you unbolt all three pots and lift them out of the cavity so that the cases no longer make contact with the shielding paint - does it still hum? Note that you'll have to temporarily reinstall the black ground wire you removed between the tone pot and the middle volume pot in order to perform this test.

Unfortunately that doesn't explain why now the neck pickup isn't humming and the bridge still is...regardless I will be swapping the pup positions this will tell me if the bridge pup is defective...if this doesn't solve the problem I intend to replace all the controls with a complete quick connect system

[Co0lCat]

well I installed a new quick connect system...bridge pup is still humming bad...the neck pup is fine...time to buy a new gold 57

[Co0lCat]

A new emg 57 gold is $139+tax, a new set is 249+tax, I found a new set for $135+tax off Reverb because there's a blemish no one can even see!

Lucky me