Page 1 of 1

The "magnet trick"

Posted: Sun Sep 27, 2020 12:00 pm
by Isaac
I'm going to try a simple mod I read about on Talkbass.

I was playing my 79 MG 4001 at band practice the other day, and noticed, as I have before, that both pickups, the way I usually play, is fine. Bridge only is fine, and a bit louder. Neck only is not fine. Oh, nothing wrong with the sound, but the volume drops out.

Here's the mod: get a rare earth magnet such as neodymium - the usual size recommended is 60mm x 10mm x 3mm and place it under the neck pickup. The increased magnetic flux will increase the output of the pickup. No need for any adhesive; it will stay in place magnetically. Depending on the configuration of the pickup, the magnet might have to be broken in two to let the wire exit. That's it.

I opted for 30mm x 10mm x 2mm. I won;'t have to break the magnet, and the 2mm thickness ought to be lower strength. Some have observed that, after this mod, the neck pickup is stronger than the bridge, and that's not what I'm looking for. And if I don't like it, I'll just remove the magnets. No harm done.

One other observation made by someone who tried it it that he had fret buzz after. Seems that the stronger magnetic field was pulling down on the strings enough to cause it. It seems to me that that should cause a change in tone, or sustain, or something!

Re: The "magnet trick"

Posted: Sun Sep 27, 2020 2:42 pm
by rickenbrother
That's a good fix that's been discussed here as well. Now that you have more magnetic flux, be careful of the pickup height as you might get some odd sounding notes, especially when playing in the upper register.

Re: The "magnet trick"

Posted: Mon Sep 28, 2020 8:47 am
by Dirk
I have never heard of this "trick", you might as well replace the pickup with one that works properly?

Or you could leave the magnet out and just adjust the pickup height to properly compensate.
It shouldn't be that much of a difference unless perhaps there's and issue with the pickup itself.
Could it be your bridge pickup is adjusted too high?

I would think this hack should be measurable, try it certainly as it shouldn't hurt.

Good luck,
Dirk

Re: The "magnet trick"

Posted: Mon Sep 28, 2020 1:00 pm
by Isaac
rickenbrother wrote:That's a good fix that's been discussed here as well. Now that you have more magnetic flux, be careful of the pickup height as you might get some odd sounding notes, especially when playing in the upper register.
I have wondered if this might be the case, and it's something I'll be looking out for.

Re: The "magnet trick"

Posted: Mon Sep 28, 2020 1:07 pm
by Isaac
Dirk wrote:I have never heard of this "trick", you might as well replace the pickup with one that works properly?

Or you could leave the magnet out and just adjust the pickup height to properly compensate.
It shouldn't be that much of a difference unless perhaps there's and issue with the pickup itself.
Could it be your bridge pickup is adjusted too high?

I would think this hack should be measurable, try it certainly as it shouldn't hurt.

Good luck,
Dirk
A $5 magnet is a lot less expensive than another pickup!
The pickup works properly. It simply has lower output than the bridge pickup. I assume that is because the bridge pickup has a larger magnet. It's quite possible, probable, even, that this is by design. With the bass blocking "vintage sound" cap in the circuit, the output of the bridge pickup is lower, and matches up better with the neck. But I like the bridge pickup full range, and, when I use the neck pickup soloed, I want it to thunder. Well, unless I choose to play it gently.
As you say, Dirk, it certainly shouldn't hurt. And if it doesn't do what I want it to, it's easily reversible.

Re: The "magnet trick"

Posted: Mon Sep 28, 2020 4:37 pm
by ilan
I've done that in the past but I prefer lowering the bridge pickup until you get equal output. If you have the handrest on, it will hits the strings as it lowers with the pickup, so you need to make a spacer, usually 3mm is just about right in my experience. Just done it last week on a friend's Shadow.

Re: The "magnet trick"

Posted: Mon Sep 28, 2020 11:17 pm
by iiipopes
The opposite solution: see if there are any grommets between the underside of the pickguard and the pickup. If so, you can remove them or cut them down to raise the pickup marginally. Just know that you cannot raise the pickup any higher than the height of the four corner screws.

Re: The "magnet trick"

Posted: Tue Sep 29, 2020 7:54 am
by teeder
Just know that you cannot raise the pickup any higher than the height of the four corner screws.
Unless you take those screws out and use some thin wire to hold the PU together. :wink:

Re: The "magnet trick"

Posted: Tue Sep 29, 2020 2:35 pm
by radapaw
I'm surprised there hasn't been more toying with magnets, "rubber" isn't exactly what they're raving about over on the bkp or duncan forums, and it seems fairly inexpensive especially when compared to the price of a new pickup.

Personally my approach is to start by jacking up the neck pickup as high as I can, then adjust the bridge to taste. I typically like the bridge a hair louder because 'needing a bit more 'cut'' is why I usually solo the bridge in the first place.

Re: The "magnet trick"

Posted: Wed Sep 30, 2020 1:22 am
by paologregorio
I've used the "magnet trick" on the underside of a couple of instruments; currently, I think just on my rick 381V69/12; the bridge and neck pickups have the same output ohms, but the bridge did not sound as loud due to proximity to the bridge, so I placed a ceramic bar magnet on the underside of the pickup from a broken hi-gain to bump up the bridge pickup output. I was happy with the results. :)

Re: The "magnet trick"

Posted: Mon Oct 05, 2020 1:14 pm
by Isaac
When I took the pick guard off, I found that the neck pickup was all the way up. There were grommets, but the corner screws were flush against the guard.

I could have used a 60mm x 10mm x 3mm magnet, as my pickup leads don't come out the center of the pickup. I understand that this varies by year; mine is a 1979.

Magnets popped right on. Didn't seem possible to put them on wrong. I had thought that it would be that way, but someone said that the magnets were so strong that they would adhere even if put on wrong. Not a problem in my case.

It did increase the output of the pickup, but not so much that it overpowered the bridge pickup. Pretty much exactly what I wanted. I haven't noticed an appreciable change in tone. I'll give it a more extensive test tomorrow. I did not notice any effects from increased pull on the strings.

So far, I like it. I'm thinking that I'll try it on my 2016 4003W next.

Re: The "magnet trick"

Posted: Mon Oct 05, 2020 1:34 pm
by admin
Isaac it is always nice when one of these tricks works out. Well done. :)

Re: The "magnet trick"

Posted: Tue Oct 06, 2020 1:10 pm
by Isaac
Taking the 4001 to band practice today. Looking forward to trying it on my 4003W!