Possible grounding issue on a '05 JP6 (with Piezo)

[vflygare]

Hi everyone!
First of all, Just got my first JP6, a guitar i've been dreaming for almost 20 years, and decided to register to the EB forums.
The guitar I bought is made in 2005 and has Piezo system.

For the first couple of weeks the guitar worked great! Felt and sounded great.
But after that the Stereo/Magnetic input started a loud hum everytime I release my hands from strings or metal parts.
Also, the volume and tone almost completely disappeared when using the Stereo input.

I just opened the back cavities and got really really confuced, haha.
I'm newbie on this matter and have very little experience with guitar electronics.
Can anyone help on where I should begin to try to locate the problem?

Thanks!

 

[Etudica]

The hum when not touching strings could be your environment and nothing wrong with the guitar or guitar grounding. I would just make sure that the cavity cover ground wire is pinched under the cavity screw properly (lots of threads with pics online if you are unsure what I'm referring to). Everything else should be soldered in place and secure.

In my last house I found that the recessed overhead LED lighting in one particular room was the cause for the same sort of hum on my JPs. It became even worse when using an appropriate dimmer switch for LEDs. Not all guitars will behave the exact same way so it may be difficult to pinpoint the interference (only my JPs picked up the hum). Very first thing to try would be to take it to another house or location and see if the hum remains in a completely different environment.

If it still happens far away from any artificial lighting or obvious EM interference, then you may want to reach out to customer service. Even though it is not under warranty, they will sell you replacement preamps and parts if they think that one of those parts may be the issue. The prices are very reasonable in my opinion.

Edit: Also replace your battery with a brand name 9v and don't use a rechargeable one

 

[Vadauco]

the Stereo/Magnetic input started a loud hum everytime I release my hands from strings or metal parts.

Try plug into another rig, in another house. If you can, also try your own rig in a different house. This won't fix your problem, but it will tell you whether your house/rig has an electrical problem or not.

 

[beej]

Hi there-

Congrats on the guitar and welcome to the forum!

Also, the volume and tone almost completely disappeared when using the Stereo input.

Can you elaborate on how your guitar is connected? Are you using a mono cable to one amp, stereo cable to two amps? Etc.

 

[vflygare]

Thanks guys for helping me! Very nice of you all.

I would just make sure that the cavity cover ground wire is pinched under the cavity screw properly (lots of threads with pics online if you are unsure what I'm referring to). Everything else should be soldered in place and secure.

I took couple of pics of the cavity. Can you see if the it is pinched correctly. I'm not even sure if we are talking about the same screw The black one i guess, which holds all the black grounding wires?

Very first thing to try would be to take it to another house or location and see if the hum remains in a completely different environment.

All of my other guitars work fine in the apartment I am living, but I guess it will cause no problem for me to try it somewhere else too

Try plug into another rig, in another house. If you can, also try your own rig in a different house. This won't fix your problem, but it will tell you whether your house/rig has an electrical problem or not.

I also have "Line6 Pod Studio UX2" connected to my computer and the same problem occurs when playing thru it, so I'm pretty sure the problem is not with my rig.

Can you elaborate on how your guitar is connected? Are you using a mono cable to one amp, stereo cable to two amps? Etc.

I'm currently only using one input at the time. The guitar is connected to Bugera head/cab with harley benton guitar cable. When using the Piezo input, the setup works great , but When i switch to magnetic, the loud hum starts and the tone and volume fades to almost nothing.


Here are couple of pictures from the inside cavities. Can you guys spot anything that isn't correct?
My untrained newbie eyes didn't see anything out of order or any of the wires didnt seem to be (too) loose or anything

 

[Daniel]

Hi everyone!
First of all, Just got my first JP6, a guitar i've been dreaming for almost 20 years, and decided to register to the EB forums.
The guitar I bought is made in 2005 and has Piezo system.

For the first couple of weeks the guitar worked great! Felt and sounded great.
But after that the Stereo/Magnetic input started a loud hum everytime I release my hands from strings or metal parts.
Also, the volume and tone almost completely disappeared when using the Stereo input.

I just opened the back cavities and got really really confuced, haha.
I'm newbie on this matter and have very little experience with guitar electronics.
Can anyone help on where I should begin to try to locate the problem?

Thanks!

Hi vflygar,
Ernie Ball Music Man guitars are designed so that the player completes the ground. That black wire running to your tremolo springs is that ground connection, along with the bare wire that sits is under your control cavity cover connect you to the ground. It's fairly normal, if you let go of the strings, for the guitar to hum. The JP6 is a loud guitar and it's active preamp will pickup noises in the signal chain that your other guitars won't. Another thing to consider is any other devices connected to the same house power can cause noise issues. This would include your computer, microwaves, fridges, etc.... I recommend trying the guitar in a different power circuit or even a different location.

 

[beej]

I'm currently only using one input at the time. The guitar is connected to Bugera head/cab with harley benton guitar cable. When using the Piezo input, the setup works great , but When i switch to magnetic, the loud hum starts and the tone and volume fades to almost nothing.

So, you're using the stereo ouput with a mono cable, into a single amp? That's what the mono output is for (it combines both magnetic and piezo outputs for a single cable).

With the stereo output, use a TRS (stereo) cable, and then you can feed two amps at once (one signal per amp). With a TS (mono) cable you're grounding one of the outputs.

 

[beej]

Hey- sorry- a bunch of these posts (including my response) were flagged for moderation and I missed them.

 

[vflygare]

Thanks so much guys!
I guess my problem is now solved; I tried my amp in a different and less crowded electrical socket in a different room and the guitar works great again!

I had my computer, speaker system, modem and amp all located in the same electrical socket. I guess that created the noise issue.

Thanks again to everyone for being so helpful

 

[Daniel]

Thanks so much guys!
I guess my problem is now solved; I tried my amp in a different and less crowded electrical socket in a different room and the guitar works great again!

I had my computer, speaker system, modem and amp all located in the same electrical socket. I guess that created the noise issue.

Thanks again to everyone for being so helpful

Glad it worked out. Let me know if you have any questions!

 

[Vadauco]

I had my computer, speaker system, modem and amp all located in the same electrical socket.

Beware an overheating, dude...