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

[Steve A.]

This is for a 1948 Gibson Century (BR-2) lap steel. It uses the non-adjustable magnetic pole pieces and has a very flat bottom and is secured with 2 screws to the plate that also holds the bridge.

The pickup is only about 0.50" tall and the string to string spacing is roughly 0.45" (from the 1st to the 6th string the distance is 2.33" center to center). These are the dimensions that are the most critical.

The basic shape is like an oversized and overweight strat pickup. The length is 3.25" and the width is 1.4".

The pickup leads come out of two holes in the bottom plate of the bobbin which need to line up with two holes in the metal mounting plate.

I estimate the DC resistance to be something like 10k. There is a break between the coil wire and the pickup lead but I did measure 10k probing around very carefully.

Oh- and the pole pieces are 0.2" diameter with an average height of 0.52".

(I guess a picture *would* be worth a thousand words here... )
If I can find someone who builds these pickups that would be great!

Thanks!

Steve Ahola

P.S. Does anyone have the wiring diagram for the 3 controls on the Century and Ultratone lap steels. This is for a single pickup so I believe that the controls are Volume, Bass and Treble. (I will be pulling the controls out and will draw up what I find.)

[jason lollar]

I dont know if you got my reply yesterday but I do make those however I have never seen one that had magnets for poles- all the ones I have seen have fixed poles sort of like a long humbucker slug with two bar magnets underneath like a P-90. Doesnt suprize me though if you found one with magnets- thats how the console grands are made.
I just made one of these fixed pole pickups out of solid tortiseshell last week- check your junk mail, I sent you a photo but maybe it regected it due to the file attachment

[Sweetfinger]

If you can probe around and get a 10K reading, I'd think that the break is near the surface and the pickup can be repaired rather than rewound.

[Steve A.]

How *NOT* to repair a pickup!

How *NOT* to repair a pickup!

If you can probe around and get a 10K reading, I'd think that the break is near the surface and the pickup can be repaired rather than rewound.

I got that reading sticking the probe in the hole in the bottom bobbin where the hot pickup lead came out. I thought that there might be discontinuity between the pickup lead wire and the coil wire so I tried heating up the pickup lead and letting some solder drip down. No such luck. There was corrosion on two of the pole pieces so I have a hunch it rotted out the coil wire in places.

So much for the 10k tap. I tried a new approach: I fed 22GA tinned bus wire where I was getting a reading with my DMM. I would drip solder down the wire when I was get a reading of 9k. As soon as I would take pressure off the wire I would lose the continuity, so I would try again with a second piece of bus wire inserted into the hole. After doing that repeatedly I finally got a reading that stayed when I let go and wiggled it around a bit. Woohoo! I'm in luck! So I mixed up some Gorilla Glue epoxy just to keep everything in place. When the epoxy cured I was still getting 9k. But when I went the lead to thread it through the hole in the bridge plate I lost continuity.

They say that the definition of insanity is repeating the same thing over and over again and expecting the results to be different. But I disagree- to my way of thinking that is just stubborn persistence! I carefully removed the epoxy and started over. This time I found a 6k tap that remained secure. I think what I managed to do was sandwich that coil wire between two pieces of bus wire that were soldered together.

So I seal it up with epoxy (why tempt fate?) and reinstall it in the lap steel with the controls bypassed. Plugged straight into my guitar amp set for a tele it is horrendously bright! I had to turn the treble and mid controls almost all of the way off to get a decent sound. I then reconnected the controls- volume, treble cut and what seems like a passive mid boost. Wow! It is like day and night! It delivers a killer blues tone, both clean and with some dirt added in. Damn- this is the slide guitar/lap steel sound I've been trying to get for 30 years.

I am perplexed how that tone circuit (see attached pic) got such a great sound out of such a harsh pickup.

I don't know if you got my reply yesterday but I do make those however I have never seen one that had magnets for poles- all the ones I have seen have fixed poles sort of like a long humbucker slug with two bar magnets underneath like a P-90. Doesnt surprise me though if you found one with magnets- thats how the console grands are made.

I got your very prompt reply (thanks!) but was checking here to see if someone here had made a drop-in replacement pickup with the magnetic pole pieces because they seemed to be quite rare. So Gibson borrowed the idea from their console grands. That makes sense because they reportedly made versions of the Century with 7, 8, 10 and 11 strings.

I attached some stock photos of the guitar and my butcher/repaired pickup, along with some sound samples I recorded tonight.

Thanks to everyone!

Steve Ahola

[Possum]

....

What is the diameter of the poles, and length of poles. Do they stick out of the top? What is the coil height of the pickup? Does it sit on steel and is attracted to it?
It'd be cool if you can figure out the controls and diagram it out. The alnico rod P90's do exist and were used in one certain archtop for a pretty short time, I've been trying to snag one for years....

[Steve A.]

What is the diameter of the poles, and length of poles. Do they stick out of the top? What is the coil height of the pickup? Does it sit on steel and is attracted to it?
It'd be cool if you can figure out the controls and diagram it out. The alnico rod P90's do exist and were used in one certain archtop for a pretty short time, I've been trying to snag one for years....

The poles are 0.20" in diameter and 0.52" high. They do peek over the top bobbin a bit. It is secured to a ferrous sheet metal plate which also goes under the bridge (I'll attach a picture of that). In that regard it is kinda like a tele pickup. I was thinking about replacing the metal plate with plastic or cardboard just to see how that would affect the tone (I think it would).

I'm going to pull the controls out to shield the control compartment (this is a player not a collector!) and can sketch out the circuit when I do that. Gibson lined the control compartment with an aluminum foil bonded to paper as far as I can tell. I thought that someone had added it until I saw pix of the Ultratone controls (the Ultratone is like the Century's rich Uncle Scrooge ).

Steve Ahola

P.S. Does anyone know if the similar pickups on the Gibson consoles also use a metal plate behind the pickup?

P.P.S. I am looking at my Chandler RH-2 with their special CC90 pickup. The top bobbin has the distinctive hexagonal shape of a Charlie Christian pickup but it is just a skinny P90 with tiny magnets on the bottom. And non-adjustable pole pieces which are not magnets. I think I will have a copy of that made with magnetic pole pieces, a tapped coil and a ferrous metal bottom plate. It looks like there is room in the control compartment for a third control- woohoo!

[Possum]

...

Cool, thanks for the info. Gauss readings off the poles?

[jason lollar]

thats funny- that is exactly the same as a console grand pickup- same lead wire exit locations, bobbin shape and pole piece arrangement and mounting plate. Exactly what I make in an 8 string- I also have 7's and 6's but i dont list them on my site. Leran something new every day.

[Quarter]

thats funny- that is exactly the same as a console grand pickup- same lead wire exit locations, bobbin shape and pole piece arrangement and mounting plate. Exactly what I make in an 8 string- I also have 7's and 6's but i dont list them on my site. Leran something new every day.

Good to know you make 7's and 6's. I've used your 8 in a couple new builds and the owners love them. Here one in in a walnut / birdseye build

[jason lollar]

thats slick!~

[Steve A.]

thats slick!~

That lap steel looks really great! I need to check the measurements on your 8 string Gibson console grands to see if it will line up with the strings on my 8 string Joe Morrell Maple Pro. The sound sample on your site for that pickup is amazing!

Steve Ahola

[Quarter]

Thanks Jason and Steve, I enjoy building them and its a great creative outlet for me. Here are some misc pics of some of my other steels

I need to check the measurements on your 8 string Gibson console grands to see if it will line up with the strings on my 8 string Joe Morrell Maple Pro.

Even if you had to route and change out or modify the stock bridge, it would be a worthy upgrade.

[Ronsonic]

How *NOT* to repair a pickup!

I attached some stock photos of the guitar and my butcher/repaired pickup, along with some sound samples I recorded tonight.

Thanks to everyone!

Steve Ahola

I have a very similar pickup from a BR9 that had sprung itself open. The problem with this one seems that the flatwork warped terribly and tore the winding. Or at least that was the theory. I haven't dug into it as I wasn't prepared to build a pickup and this will need new flats and rewound. Almost a ground up build around the old magnets.

I'll dig it up and post some photo's.

This was from a severely boogered piece brought in by a little old lady and it had been "refinished" with house paint. To get it back to her working , I hacked in a random humbucker (modded the p/u frame to fit, not the piece) replaced the tuners, strings, fixed the electrics and basically no charged the whole thing. A couple years later, someone dropped it off at the shop, explaining that she wasn't playing anymore and she knew I liked it. Wow. I still can't play it worth a damn.

[Steve A.]

This was from a severely boogered piece brought in by a little old lady and it had been "refinished" with house paint. To get it back to her working , I hacked in a random humbucker (modded the p/u frame to fit, not the piece) replaced the tuners, strings, fixed the electrics and basically no charged the whole thing. A couple years later, someone dropped it off at the shop, explaining that she wasn't playing anymore and she knew I liked it. Wow. I still can't play it worth a damn.

That just goes to show that no good deed goes unpunished.

Thanks for sharing your story and I can't wait to see the pix. To me these pickups that Gibson used just for 2 or 3 years are like a missing link (you do have the oval one with the magnetic pole pieces- right?)

Steve Ahola

[Ronsonic]

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.