Any point to having a bottom plate on a dual-rails Tele bridge PU?

[Mark Hammer]

Heading pretty much says it all.

I was given an older Duncan Tele bridge PU of the dual-rails type. And given that the sensing area is between the two rails, I was wondering if a bottom plate would play any role whatsoever.

[jrfrond]

Rails-type pickups are almost always bottom-loaded, with a bar magnet set between the rails. A bottom plate is not just pointless, but might be impossible to fit. I've never looked at the Duncan version from the back, but I would bet on the rear bar magnet.

[Mark Hammer]

Well your guess is accurate. It's a bar on the bottom and blades on either side, and a fairly high DCR (around 13k). It was given to me a couple years ago, and I think it came with a bottom plate, but can't be sure whether the plate sitting in the pickup parts drawer is from that or another.

But yeah, my gut sense was that it would serve no useful role in distributing the magnetic field. I was just wondering whether it was supposed to add some steel to affect inductance or something like that. It appears to be an older model that is not part of the current Duncan catalog, so I have no guidance there.

[FunkyKikuchiyo]

My guess is that would sound horrible. Adding the metal mass would probably cause more losses of high frequency content (ducks throwing vegetables) which solid blade pickups seem to lack to begin with.

13k is high! Old generation hot rails, maybe?

[Rick Turner]

DCR can be very misleading. I wind humbuckers directly on ceramic 5 cores at close to 11 K per coil for a total of about 22 K. I'm using 44 ga. wire, though, so it doesn't mean the same thing as if I were winding 42 gauge.

[FunkyKikuchiyo]

I hear you Rick, but the last time I checked DCR on a Duncan rails model, it was in the 3-4 kohm range.

[Mark Hammer]

This PU is from about 10-12 years ago, if not farther back. The original owner gave it to me because he said it was just too darn hot for his tastes (and probably will be for mine, too). So I gather this was overwound, rather than a result of using wire with a higher resistance per linear foot.

Rick has a cogent point, but my guess is this pickup is afflicted with Dimarzi-itis, circa 1978.

[jrfrond]

You could always run the coils in parallel, or do the series-parallel switch thing, ANOTHER original DiMarzio feature!

You could also swap magnets for a sonic change. I don't recall what those pickups were loaded with, but I THINK it was ceramic.

[David Schwab]

The Hot Rails are 16.9K for the bridge and 10.8K for the neck and middle. Cool Rails are 10.3K and 9.4K.

A steel plate on the bottom would short out the magnetic circuit.

The best bet is to wire the pickup in parallel. I find a lot of these dual rail pickups try to imitate a full size humbucker too much. I installed a Little '59 in a Tele, and hated it. It was very muddy sounding. I have some no name dual rail bridge pickup in my Tele, and that sounds a lot better, but it's still wound a little too hot. I use it in parallel a lot of the time.

You wont be able to swap magnets because you wont find an alnico magnet that narrow.

[jrfrond]

You wont be able to swap magnets because you wont find an alnico magnet that narrow.

Wasn't sure if that PU was Alnico or Ceramic. If it were Alnico, he could switch from 5 to 2. Wouldn't change the DCR though.

[FunkyKikuchiyo]

TI find a lot of these dual rail pickups try to imitate a full size humbucker too much. I installed a Little '59 in a Tele, and hated it.

Couldn't agree with you more. I never understood the whole "humbucker in single coil size" market. The little '59 I think is better than most... not my cup of tea, but not bad. They all end up sounding incredibly nasal.

I'll never forget the Martin I played with a steel top, bigsby and Tone Zone S... no, I'm not joking. Yes, it sounded as horrible as you think.

The magnet in it is ceramic. Very seldom will you find a blade pickup with alnico. They tend to be very muddy. I may experiment with it some day - but it isn't high on my list at the moment. Swapping with alnico would probably make it worse. However, if you could swap the blades and you're ambitious enough to make a laminated blade, then you'd be on to something...

[David Schwab]

Wasn't sure if that PU was Alnico or Ceramic. If it were Alnico, he could switch from 5 to 2. Wouldn't change the DCR though.

I don't think an alnico magnet that narrow would hold a charge. You need a 1/4" wide magnet.

[David Schwab]

Couldn't agree with you more. I never understood the whole "humbucker in single coil size" market. The little '59 I think is better than most... not my cup of tea, but not bad. They all end up sounding incredibly nasal.

I'll never forget the Martin I played with a steel top, bigsby and Tone Zone S... no, I'm not joking. Yes, it sounded as horrible as you think.

The magnet in it is ceramic. Very seldom will you find a blade pickup with alnico. They tend to be very muddy. I may experiment with it some day - but it isn't high on my list at the moment. Swapping with alnico would probably make it worse. However, if you could swap the blades and you're ambitious enough to make a laminated blade, then you'd be on to something...

The problem with some are they are wound too hot, then they either get midrangy, or too bass heavy. The Little '59 was too bass heavy to me. But I guess if people like pickups like the JB they would like the Little '59 (or the JB Jr., which I haven't tried). I like the pickup in my Tele, but I'd like it better if it were wound a little cleaner.

The Cool Rails and similar (like the DiMarzio and Barden) sound pretty good. For me I want a dual rail single coil size pickup to sound like a single coil, or somewhere between a single coil and humbucker.

[jrfrond]

I don't think an alnico magnet that narrow would hold a charge. You need a 1/4" wide magnet.

You are probably right. Not enough mass to maintain the gauss level.

There's certainly nothing wrong with the SC-sized HB pickup idea, but as Dave pointed out, the "hot" versions are often TOO hot, and become one-dimensional. I lost my taste for overwound pickups a long time ago. They were fine in the 80's when everyone was using uber-EFX rigs, and the actual guitar tone really didn't mean much. You just needed a hot, midrangey signal to punch through the multiple stages of gain loss. I'd rather here the pickup breathe a little. Barden has it right for Tele rails, in my opinion. There are some decent stacked designs too, but a lot of them "feel" hard and sound a bit sterile, plus suffer from a lack of depth due to low-frequency phase cancellation, which is inherent in the stacked design.

[Rick Turner]

The issue with Alnico holding a charge is not it's width, it's the width to length aspect ratio which, with Alnico 2, for instance needs to be better than 1:5. You can have very narrow Alnico magnets hold reasonable charge if the length is right.