PRS 509 Bridge Humbucker Feedback

[TeaJayAye]

Hi there. New to the forum! I recently purchased my third PRS Core guitar, which is a PRS 509. I have a CU24 and a McCarty 594, which are two of my all-time favorite guitars.

I've been having an issue with my PRS 509 that I'm not sure is normal. When using the bridge pickup in humbucking mode, the feedback is uncontrollable with any amount of gain beyond what I would describe as "classic rock" level.

I own a Mesa Mark V and an EVH 5150 iii, and this thing squeels like you wouldn't believe when playing the Mark IV setting on my Mark V or the blue channel on my 5150 with the gain around noon and a little boost out front.

Is this normal? Pretty disappointed, if I'm being honest. Purchased second hand and can't return it. Guitar plays phenomenally, but the feedback is just uncontrollable.

Any ideas?

Thanks and Happy New Year!

 

[Birdsofprey]

Have you tried adjusting the pickup height? Sounds to me like it’s way to close the strings.

 

[TeaJayAye]

Have you tried adjusting the pickup height? Sounds to me like it’s way to close the strings.

Thanks for your reply! Yes, that was what I thought - that the pickup was too close to the strings and the output of the pickup is just too much for the amp. Sadly, that did not solve the problem. Wondering if maybe I need to have the pickup wax-potted....

 

[Maertl513]

As far as I concern - by the report of a dear friend and owner - this is normal.
The argument with too much output of the pickups is wrong, because they are low output pickups.
509 pickups are wax-potted.
My recommendation is to review your standing position towards the amp/box.

 

[TeaJayAye]

As far as I concern - by the report of a dear friend and owner - this is normal.
The argument with too much output of the pickups is wrong, because they are low output pickups.
509 pickups are wax-potted.
My recommendation is to review your standing position towards the amp/box.

Thanks, this seems to occur even when standing 8-10ft away and facing away from the amp.

 

[Maertl513]

I do have two 513s, one with PCB, one with PtP. The PtP is by design more sensitive to external influence than PCB, but I didn't recognize any feedback issue. And PtP is aswell part of the internals of 509s.

In the constructive context I have no additional recommendation, the pickups are waxed.

In the processual context you increased the distance towards the amp and turned your back to it, too.

Additionally you could increase the distance between pups and strings - but - educated guess - the guitar was likely tested in the factory without annoying feedback. Other than that they would have adjusted a different set-up.

Thereby you better focus on your amps. Roll back highs and mids and the gain, too.
And, if master and channel volume could be adjusted, experiment with their ratio.

 

[Herr Squid]

If that feedback is a high-pitched squeal that doesn't change with the notes you're fretting, then it's probably a microphonic pickup. That's a defect and your dealer should help you get it fixed by PRS.

 

[bodia]

If that feedback is a high-pitched squeal that doesn't change with the notes you're fretting, then it's probably a microphonic pickup. That's a defect and your dealer should help you get it fixed by PRS.

Good call. I seem to recall someone posting the same issue and that was the fix. Wasn’t all that long ago, either.

 

[TeaJayAye]

If that feedback is a high-pitched squeal that doesn't change with the notes you're fretting, then it's probably a microphonic pickup. That's a defect and your dealer should help you get it fixed by PRS.

I'm thinking this is the issue. I don't have the feedback issue with the center or neck pickups (including with the neck pickup in humbucker mode). This was purchased in a private sale second-hand (though in mint condition), so I don't have a dealer to help me with this. I do have a well-known luthier near me who is willing to take a look at it.

I'm going to bring it there. It doesn't make sense that the feedback issue would persist after dropping the pickup height quite a bit and keeping distance between me and the amp.

 

[Maertl513]

These pickups aren't average pickups. I take as the evidence the pictures of my 513, because the whole contruction of the pups remained the same, though they are wired differently.

The PCB as a ground plate is very sensitive. When you or the guitar tech breaks it by unscrewing not slow and sensitive, the whole pickup will become trash.
I personally would appoint the next official PRS dealer to ask, if he could route the guitar - depending where you live - to Stevenville's PTC or PRS Europe's PRS Tech Centre in Cambridgeshire. Either ways I would discuss that issue first with PRS Customer Service (USA), if they would provide an educated guess prior any repair.

 

[dogrocketp]

Unless the luthier was trained at the PRS FACTORY, I wouldn’t let him at the pickups. They’re very idiosyncratic and bad things can happen. It’d be off to the factory for me.

 

[TeaJayAye]

To anyone reading this in the future:

It seems when you add gain after this particular guitar, there's a massive frequency spike in the 2.2khz range. That results in a terrible whistling sound and lots of feedback. If you're having this problem, use an EQ to cut a narrow band in that range. See if it solves your problem.

 

[Alnus Rubra]

These pickups aren't average pickups. I take as the evidence the pictures of my 513, because the whole contruction of the pups remained the same, though they are wired differently.

The PCB as a ground plate is very sensitive. When you or the guitar tech breaks it by unscrewing not slow and sensitive, the whole pickup will become trash.
I personally would appoint the next official PRS dealer to ask, if he could route the guitar - depending where you live - to Stevenville's PTC or PRS Europe's PRS Tech Centre in Cambridgeshire. Either ways I would discuss that issue first with PRS Customer Service (USA), if they would provide an educated guess prior any repair.

If this is your guitar Martin, brave man removing those pickups.

 

[Maertl513]

It's absolutely mine. I did it driven by curiosity about the detail of the mod. Being very aware of the sensible baseplates of the pups, I turned the screws very slow and alternate, to get the pickups free. To mount them again, the same.
The proper pickup height was adjusted by my trustful tech, I wasn't glad with my own attempt's result.

 

[Glide-bpm]

Good call. I seem to recall someone posting the same issue and that was the fix. Wasn’t all that long ago, either.

I had mine replaced in my first 509 right before we ordered the Brian's Run 509's.......

 

[d^rren]

Is it "musical" feedback, or is it an uncontrollable, microphonic squeal? It could be a broken coil or failed potting of the pickup. It probably needs to be repaired by PRS.

 

[Glide-bpm]

Is it "musical" feedback, or is it an uncontrollable, microphonic squeal? It could be a broken coil or failed potting of the pickup. It probably needs to be repaired by PRS.

Microphonic non-musical squeel. My current 509 Purple Iris does this some with me particularly with higher gain tones!

 

[TeaJayAye]

Is it "musical" feedback, or is it an uncontrollable, microphonic squeal? It could be a broken coil or failed potting of the pickup. It probably needs to be repaired by PRS.

It was an uncontrollable squeal. When I turned the gain down low enough, it went away. I noticed when I turned off my noise suppressor (a ISP Decimator G String II, running both in front of and in the loop of my Mesa Mark V) that there was a "whistling" frequency somewhere in the upper mids. When I identified that frequency and pulled some of it out via the multi-band EQ on my amp, the problem went away. I then ran a few of my other humbucker equipped guitars through my set up. When I pushed that frequency too high, same problem. Something about my signal chain created the issue and it just took me a while to sort it out. My 509 just seems to have more of those upper-mid frequencies.

 

[TeaJayAye]

Microphonic non-musical squeel. My current 509 Purple Iris does this some with me particularly with higher gain tones!

I think a lot of high-gain amps push the upper-mids to get that cutting "searing" type distortion sound. The pickups in the 509 just seem to push those same frequencies more than other pickups. I was able to tame the issue, thankfully. My 509 is also purple, but I think it's a different finish than purple iris. Beautiful guitar.