MFD squealing once again

Hey Guys!

Had a previous post for this but it kinda sunk under. So i got a new Doheny which had a microphonic bridge PU at first, got a new pickup set in by Thomann guitar center.

And now its the same problem all over again. The bridge pickup starts squealing (although later than the first one) on high(er) gain in the OD Channel as soon as the volume pot is higher than 7.
Do normal P90s fit the cutout or are there any other alternatives to the MFDs? Really pissed of by this BS right now, since I ordered it in january and it spend nearly 7 weeks just in shipping back and forth now.

Out of curiosity, did your replacement pickup ever not squeal? It's odd that such an issue would happen suddenly. If the guitar is still in warranty I would not recommend anything other than contacting the retailer to have them make it right - But the solution is probably that the pickup does not have sufficient wax potting. This is something you can do yourself if you're careful (at risk of voiding the warranty I'd imagine) or have a luthier do.

If you are set on replacement pickups, then while I have not ever tried doing so- my understanding is that the MFDs in a Doheny have the same footprint as Jazzmaster pickups. I have used many Seymour Duncan Jazzmaster pickups without squealing issues, though I can't vouch for how they'd combine with the neck MFD, and still hope you can get this resolved under warranty.

The MFDs on my G&Ls are the only pickups I roll the tone knob back on by default. Especially when playing through high gain, but you may want to try that before you go down a pickup rabbit hole. Start with your volume up all the way and try rolling back the tone just a bit to see if that stops the squealing.

Check out this post in our Knowledgebase (if you have not already seen it),
as it covers the areas where an MFD pickup can cause it to go microphonic: How do I fix MFD bridge pickup squealing problem?.

Hope this helps.

Out of curiosity, did your replacement pickup ever not squeal? It's odd that such an issue would happen suddenly. If the guitar is still in warranty I would not recommend anything other than contacting the retailer to have them make it right - But the solution is probably that the pickup does not have sufficient wax potting. This is something you can do yourself if you're careful (at risk of voiding the warranty I'd imagine) or have a luthier do.

If you are set on replacement pickups, then while I have not ever tried doing so- my understanding is that the MFDs in a Doheny have the same footprint as Jazzmaster pickups. I have used many Seymour Duncan Jazzmaster pickups without squealing issues, though I can't vouch for how they'd combine with the neck MFD, and still hope you can get this resolved under warranty.

I'd really love to have them pay for it and get it right, but right now it's either giving it back and go for a Fender or fix it myself. I saw some tutorials on potting on youtube, it doesnt really seem to be that complicated, guess its just melting parafin and bees wax and dunking it for a while, right?

Last resort would be dumping the MFDs for a full set of Jazzmaster Pickups. Is there a set you would recommend?

Answering your first question, i dont really know...ordered this guitar first week of january and right after I unpacked it i noticed it had the squeal. Had to send it back to Thomann, they said there is nothing wrong and they "checked" the wiring as well. Got the guitar again, same fault, same procedure. Send it back to have them change the bridge PU, got it back yesterday and took it to rehearsal...guess what.

Are those pickups just not made to be played on higher gain?

Is it necessary to get the plastic cover off the PU for potting? or does it go as one piece into the bath?
Decided to do this on my own for now, as it is the easiest and quickest fix if it works out.

What is your setup that you are playing the guitar through? In my practice setup I'll play through my computer using software amp/effects models. I can't use ANY distortion settings at reasonable volumes without getting massive feedback. This is true regardless of the guitar I am using. Perhaps adjusting your settings could help?

Playing a HT50 Head on the OD channel, with a boosting TS9 infront for the Drive Setup. Havent had any issues with any other guitar except for the Doheny.
Same issue on a silver jubilee, not even cutting out the ts9 made a major impact so far...

There’s not anything mechanical that should make the G&L pickups more susceptible to producing feedback - though I don’t have any experience with the Doheny in particular, I’d imagine that (like other MFDs) they can be used with a decent amount of gain. Have you tried playing in a different room or with the amp angled/on a stand? Sometimes you just end up in the ‘sweet spot’ for a squeal on that particular guitar.

If you pot, you don’t need to pot the cover. To be extra secure you could also add additional/more firm padding behind the pickup to keep it from moving. If you swap pickups, I like the Seymour Duncan ‘hot’ Jazzmaster set. Good luck.

Make sure when you pot these that you keep the temperature 60 C (140 F). Lindy Fralin has a good post about his method. If you pot them too high you run the risk of damaging the pickup. Good luck!

Guys, thank you for all your answers! Going to pot them tomorrow and hopefully this will fix the squeal! Is there anything to look out for when removing the covers? are they just clipped in?

When potted correctly, it is difficult to remove the covers as the wax will hold the cover in tightly. If not, then the covers should pull off very easily. I recently had to re-pot an 80s era MFD Jumbo, the potting had failed (same squeal) and it pulled right off. Its matching bridge pickup was held in tightly by the existing wax...

More on wax potting an MFD pickup, see: My MFD went massively microphonic! Suggestions?.

Hope this helps.

Again not sure how close the Doheny pickup pattern will Follow Fender’s mold - but Jazzmaster pickup bobbins tend to leave plenty of room for the cover to slide on, once potted. The cover is glued on recent Squiers, and needs some careful pulling to remove without splitting the bobbin. Covers on MFDs that are not Doheny do tend to be on tighter from my experience; not sure what to expect, please let us know how it goes

Hey Guys,

short update on potting, job is done now and i'm going to test in on real-world conditions tomorrow. Guitar seems to work fine for now.

If you want to see the buchery for yourself, take a look at your own risk

https://imgur.com/gallery/XeY9ZsS

This was all pretty much done the DIY-way on a tight time-budget in a friends kitchen, so no fancy crockpots or luthier-tools involved.

Let us know how it works... I think I responded in your previous thread. I'd have assumed these pickups come right out of the factory potted. Just being potted doesn't mean the pickups can't feed back. Or that feedback is a problem.

It all depends on how your amp is setup and how long your cables are.

I haven't had a lot of electric guitars but I've never seen a pickup I can't make feedback on my Orange amp. My USA Doheny is no exception, it feeds back if I gain everything up enough. But that is not a problem, it is controllable and can be awesome.

Are you playing a clean amp at modest volume and still getting uncontrollable feedback?

This is very subjective. To give an idea of what I'm talking about my amp is an Orange Rocker 15. On the gain channel I usually play with the gain up about 2 o'clock. My Doheny will not feedback like that even with the volume on 10 on the guitar, but if I then turn on either my Overdrive (JHS Morning Glory) or my Op-Amp Big Muff Pi it'll go into feedback territory at higher settings on the guitar volume knob. I use a 10ft cable to my pedal board and 10ft cable from the pedal board to the guitar. If I'm in this scenario where I can make feedback start I can control it either my moving further from the amp, dialing back the volume on the guitar, or turning the pedal down. It is not hard to control.