Is anyone here making the pre-50's P90s?

[Steve A.]

Hi, I didn't forget this thread, but it took forever to dig up that pickup. I seem to have misremembered it. The bobbin is some bakelite like material, very thick, dense and slightly warped. There are two P90 style magnets. Oh, and a lot of rust.

I saw these pickups on some of the 50's lap steels that Gibson made. It seems like it was only the 1947-49 pickups that had the magnetic pole pieces.

Thanks!

Steve

[David Schwab]

Hi, I didn't forget this thread, but it took forever to dig up that pickup.

You need to set your camera on macro mode. Then it will focus up close.

[Ronsonic]

What I need is a camera that actually has a macro mode. No little flower on my menu or selector switch.

[frankfalbo]

Get farther away and use the zoom. That should be better than fish eye-ing up close.

[RedHouse]

Steve, a little off-topic but ...I gotta love your avitar!

Quick-draw McGraw ...yeah baby!
(dang where'd I hide my El Kabong avatar...)

BTW are you the same SteveA from AX84 years ago? if so ...good to see/hear from you.

[JGundry]

I have rewound a couple of these that were dead. I think the bobbins may be Delrin. All I have seen are very warped.

[David Schwab]

I have rewound a couple of these that were dead. I think the bobbins may be Delrin. All I have seen are very warped.

Delrin was invented in 1952. DuPont got patent in 1956 and first started making it in 1960. Celanese started making it under the names Celcon in 1962 and Hostaform in 1963.

So I don't think there are any pre 1960 P-90s made from Delrin.

Polyoxymethylene plastic - Wikipedia, the free encyclopedia

[JGundry]

The plastic seems too soft for it to be bakelite IMO. I think it is some sort of cellulosic nitrate plastic.

[David Schwab]

I think it is some sort of cellulosic nitrate plastic.

I agree.

[Possum]

Steve, I just won one of these on Ebay for real cheap. Did you write down the control circuit diagram in that lap steel by any chance? I also bought another one that was in an ES125 but it arrived dead so sent it back for refund. It was same design but had hand cut bobbin flatwork, alnico rods and had the harness with it, with standard controls 500K and .020uf tone cap. It must have been awful bright. I offered to fix it for free for the dealer but he has it in his mind that this is some really rare pickup worth alot of money, lol. Rare they are but desirable they just aren't. To my knowledge Gibson never patented either of these alnico rod pickups and they weren't made for very long. I also saw another version like the P90 flatwork type but the poles were flush with the flatwork and the dog ear cover was undrilled.

[Possum]

Found it:
http://bb.steelguitarforum.com/userp..._diagram_2.jpg

[RedHouse]

Steve, I just won one of these on Ebay for real cheap....Rare they are but desirable they just aren't....

And so begs the question ...why bother?

[Steve A.]

Steve, I just won one of these on Ebay for real cheap. Did you write down the control circuit diagram in that lap steel by any chance? I also bought another one that was in an ES125 but it arrived dead so sent it back for refund. It was same design but had hand cut bobbin flatwork, alnico rods and had the harness with it, with standard controls 500K and .020uf tone cap. It must have been awful bright. I offered to fix it for free for the dealer but he has it in his mind that this is some really rare pickup worth a lot of money, lol. Rare they are but desirable they just aren't. To my knowledge Gibson never patented either of these alnico rod pickups and they weren't made for very long. I also saw another version like the P90 flatwork type but the poles were flush with the flatwork and the dog ear cover was undrilled.

These pickups are rated very highly by many lap steel players in the Gibson steels that used them: the Century, the Ultratone and the BR-9. Yes, they are very bright, especially mounted with the poles 1" away from the bridge. But that was typical for many lap steel pickups back then usually mounted right next to the bridge. The trick was to start with the tone control set to 0 and then crack it open very slowly until you got the tone that you wanted.

In my Century 6 all 3 controls were reverse audio so you could just barely breathe on the middle (treble-cut) tone control and it was already way too bright. So I switched the wires at the outside terminals to get an audio taper, although fully clockwise is 0 and fully CCW is 10. (Gibson very thoughtfully cut off the unused terminal so as to not confuse the assemblers so it was kinda tricky to solder to it.)

The pickup in the Gibson lap steels is often referred to as their "wide oval" pickup and were usually wound to 9k or 10k. The string spacing is very wide- definitely unusable in a regular guitar (~ 2 3/8" center to center of the two outside poles). Although the lap steels using that pickup are valued highly by many players, the pickup itself is of little value unless you need one for your lap steel.

BTW Fender applied for a patent for the tele bridge/pickup assy in January of 1950 which might have something to do with Gibson discontinuing to use it since their pickup was very similar to the tele, but with a shorter and wider coil.

Steve Ahola

[Possum]

Why bother? Its a historically interesting piece. These things were completely hand made, baseplate, bobbins, everything. I was particularly interested in the core dimensions, and the design differences between this one and the one used in ES125's, of which there were few. I learn something from everything I've looked at, and its literally touching the past. I would have kept the one I sent back but $300 for a dead pickup was a bit too much, plus I was able to document everything about it and take alot of photos, so I got all my questions about it answered, except how does it sound? I know it was bright but still would have loved it if it had been a working coil. It died in shipping, he told me his ohmeter was giving him "varying readings" which I should have realized meant it was on its last breath. I'm mocked up a repro to throw in neck position once I wind it, happened to have some alnico magnets darn close to what was in it, so curious to hear the tones. I found two net posts on DCR for the lap steels at 6.63K and 7.64K, the ES125 version was 7.8K before it died.

[Steve A.]

I had Pete at Vintage Vibes make me a replacement for the dead one in my Century 6 (there was corrosion around the pole pieces on the bottom plate which evidently ate through the windings). He made me one with 3 taps- 6.5k. 7.5k and 10k figuring that one of those would work for me. The 7.5k tap sounded the best to me so that is what I used. I recently got a BR-9 with the same style pickup; it has a DC resistance around 9.5k and sounds really nice. Some lap steel players prefer the smoother sound of the P-90 style pickups used in the 50's but they both have their charm. (The P-90 has the wider string spacing, too.)

Steve