First PRS - Custom 24-08 - Humming on humbucker and single coil

[Andrema2]

Hi,

This is my first PRS guitar and my first post. This guitar is a week old. Since I got it I hear a humming or buzzing from the pickups. If I put my finger in the strings it stops. If I put my finger on the screw that adjust the pickup height the humming gets louder. It happens in humbucker mode too is a little bit lower on it.

I'm not sure if this is a normal pickup behaviour as it is with a single coil pickup or if I have a ground issue or something else ?

I read some other posts and i didn't find a clear answer.

 

[Lewguitar]

If you bought it locally take it back to the store and compare it to others of the same model.

It sounds like the ground is reversed somewhere and that the metal pickup body and polepieces of the pickup are hot instead of grounded.

When you're using a humbucker and you touch the strings any hum should pretty much stop.

You should be also be able to touch the metal of the pickup with your hand and stop the hum because it should be connected to the same ground wire in the control cavity that your tailpiece and your strings are.

Something's not right.

 

[László]

It's completely normal for a single coil, or a split humbucker to pick up electromagnetic and radio frequency interference. Dimmers, computers, proximity to the amp's transformers, lots of things cause it.

Some dimmers will even make humbuckers buzz a little, since the coils rarely perfectly out of phase.

I'd call PRS customer service (don't email, it takes forever). See what they say and perhaps let your dealer handle any issues.

 

[darkbluemurder]

It is completely normal that the buzzing is reduced as soon as you touch the strings or the bridge. The reason is that the strings are grounded (normally through a wire that connects the bridge to ground, either on the back of a pot or directly to the ground connection of the jack). When you touch the strings, your body gets grounded and becomes a shield against outside interference. This appears irrespective of the pickup type.

There is not much you can do to solve that. In the 70s Gibson used a complex grounding and shielding system, consisting of shielded wires, a metal box for the electronics, a shielded jack and covers on the humbuckers. That worked so well that they were able to omit the bridge ground. However, if you take off the covers or replace the pickups with uncovered ones, the peace is over . In addition, it is very difficult if not impossible to install such a system on any other guitar.

If the noise increases when you touch the pickup adjustment screw, this means that for some reason the screw is not grounded. It should be because it is connected to the pickup's base plate. It looks like the base plate is not grounded. I would check that with a multimeter. This issue is also independently of whether the pickup is used as a humbucker or as a single coil.

Good luck,
Stephan

 

[sumitagarwal]

This thread is a bit older now but I recently installed a set of TCI "S" pickups (recent all-black revision out of an SE 24-08) and experienced the exact same issues: higher overall noise than my vintage-style Strat, slight noise reduction when touching the strings (as is normal), but large noise increase when touching the height adjustment screws of the selected pickup.

I checked through and tested my wiring, but saw that this seems to be a common issue with TCI "S"s, especially the more recent 24-08's. See threads below, including some with PRS customer support feedback:

https://www.reddit.com/r/Guitar/comments/t17ldk

https://www.reddit.com/r/guitars/comments/116jxzk

Advice needed: SE Custom 24-08 wiring/grounding issue

Hi folks, did anyone here take a look inside their SE Custom 24-08? I have a serious suspicion the wiring/grounding on mine is off. What comes out of the neck pickup is a red heat shrink tube that only has the four red/white/black/green strans - no bare wire. The bridge pickup has a green heat...

forums.prsguitars.com

Basically PRS took the unusual step of leaving the metal humbucker baseplate ungrounded, presumably to achieve a more traditional split-coil tone. So there is a big chunk of ungrounded metal immediately adjacent to the coils. I think this is a sort of design translation from the USA TCI pickups which look like they have fiberboard baseplates instead of metal baseplates, and so they avoid the problem of that big ungrounded piece of metal right there.

It also appears that at some point in the TCI "S" revisions, they may have switched from nickel baseplates to brass baseplates, which could have exacerbated the issue which is why it seems more common on SE 24-08's.

Net-net: a simple fix the noise is running a wire from the pickup mounting screws to ground. Or, maybe, the TCI "S" pickups can be upgraded in noise and tone by swapping the metal baseplates for fiberboard ones?