P-90 neck, “Tele” bridge partscaster help

TyronicusRex

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I’m trying to get a relatively balanced sound between a Duncan P-90 neck pickup and a generic (StewMac maybe?) Tele bridge pickup. I built this guitar on a whim when I realized I had enough scrap parts, and it played OK, but the P90 way overpowered the bridge PU.

The deets: Neck P-90 measures 9k ohms Bridge Tele measures 7k ohms. Originally I used 250k volume and tone pots, and a capacitor marked 473M for the tone bleed.

Research on this forum suggested I should switch to 500k pots, and “wire a 470K resistor to the terminal of the pickup selector switch where your bridge pickup is wired with the other side (tail) of the resistor to ground. This will make the bridge pickup continue to electronically 'see' a 250K (or close enough to it) pot.”

Having forgotten everything about electronics, I tried to follow these instructions, but ordered a 470 ohm resistor, not 470k, and replaced the pots w 500k. IIRC, the guitar put out no signal at all when I was done.

So, I pulled the resistor, and wired it like any regular Tele. Now both pickups work, but the neck pickup is a bit shrill, and the middle position sounds out of phase, like a wah pedal cranked all the way forward. It did NOT sound that way before.

So, any recommendations on how to fix it?
 

Carcinogen

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Your neck pickup has a higher output than the bridge pickup, so it’s going to take the already louder string vibrations near the neck and give them a boost.
 

jfgesquire

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Well, the theory is correct for the pot and resistor, with the right size. So try again, running a 470k resistor from the lug on the switch where the hot wire from the bridge pickup attaches and the other end to ground.

It’s the same for a humbucker in the neck. In fact if you google search “HS TELE 470k” you’ll get lots of images of diagrams.

The only other thing I would do is add a no load tone pot. My P90 was not as bright as I wanted and the no load on 10 completely eliminates itself, so the pickup is straight to output with only the 500k volume pot in the path.

As for the out of phase sound, check your polarity and wrap. I can help with an easy test for that if you have a multimeter.

I played with the magnets and wiring on my P90 so that it would be RWRP with my bridge pickup. I installed a 4-way, so series and parallel are available and it is dead quiet.

Good choice, by the way, it will end up worth it. 9CDA3133-F697-4163-AB18-82B6C8AE3251.jpeg
 

Carcinogen

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Yes, you’ve accurately described the problem. The question is, what can be done to remedy it?
Adding resistors to make the bridge see 250k and the neck 500 isn’t going to fix a volume disparity. You can drop the neck pickup down till it’s inside the pickup cavity but then you’ll loose all your definition and attack. You’ll need to either find a really low output p90 to go in the neck to match with the existing bridge pickup, or get an extremely hot bridge pickup to match with the existing p90. Like, a 5-6k p90 or a 10-11k bridge pickup. You might be able to do something with concentric volume pots so you can have the bridge dimed and then pull back on the neck to match volume, cts makes a stacked 250/500k unit. A treble bleed could be useful on the neck pickup if that’s the case.
 

birdawesome

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I can’t speak for the output discrepancy you’re having, and I’ve not tried to remedy this in the past.

As for the thin/out-of-phase-sounding pickups, check to make sure that, well, they aren’t wired out of phase. Also check that you’re still getting the same readings on your multimeter from the pickups in case they were somehow damaged along the way...maybe even a lead got chewed up in between the pickup and the switch and is barely holding on internally. If you can verify that your wires are correct, maybe go back over your solder joints again. A cold or dirty joint could be causing a bad connection. Worst comes to worst, I’d replace your switch followed by the pots and just working backwards from the pickup until you’ve solved the problem.
 

JRapp

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I did the P90/Tele bridge pickup thing back in the 90s and a P90 will overwhelm a stock Tele pickup due to its bass response, etc. Solution---remove 1 magnet from the P90. That will drop some low-end and output. Yes, it will work and some very early P90s only had one magnet.
 

schmee

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P90's sound good away from the strings most often. Try putting it 1/4" from the strings and the pole screws down and the bridge pickup up close to the strings.
Or get a good hot bridge pickup, like a Tex Mex for $30

Sounds like something is grounded or wired wrong now though, your neck pup should not be "thin".
 

TyronicusRex

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As for the out of phase sound, check your polarity and wrap. I can help with an easy test for that if you have a multimeter.
Yes please! I was flummoxed by this. I also don't exactly have the hang of soldering those braid-shielded wires on the P-90.
P90's sound good away from the strings most often. Try putting it 1/4" from the strings and the pole screws down and the bridge pickup up close to the strings.
Or get a good hot bridge pickup, like a Tex Mex for $30
You can get a good Tele pickup for $30? I need to know where!
 

schmee

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Yes please! I was flummoxed by this. I also don't exactly have the hang of soldering those braid-shielded wires on the P-90.

You can get a good Tele pickup for $30? I need to know where!
Full sets of Tex Mex were about $75-80 for a Strat! (3 pickups)
Tele's were about the same for the two.
Not sure if they have gone up or not, but not too much I dont imagine.
Here's a new single for $45: https://www.ebay.com/itm/2340010448...K9yQn2Nh8tEEAVkzLJLAvXYQ==|tkp:Bk9SR8T1tsjXYA
Set for $80 now: https://www.ebay.com/itm/2949652070...539J8ukFY6jfLd7r0PW+OH6fiG|tkp:Bk9SR8T1tsjXYA

Maybe someone here has a single to sell you for less.
 

Boreas

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I would see how close you can get by lowering the neck and raising the bridge. If the bridge doesn't have a metal plate, you could try adding one. Sometimes that helps with definition. But if you track down the cause of the OOP middle position, you may also find you get a boost on the bridge if it is a bad solder joint.
 

jfgesquire

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Yes please! I was flummoxed by this. I also don't exactly have the hang of soldering those braid-shielded wires on the P-90.

You can get a good Tele pickup for $30? I need to know where!
The P90 is similar to the Tele neck pickup as far as how the wires are concerned. There are leads soldered to the start and finish coil ends.

The other end of the wire attached to the start wire will also be soldered to the metal base plate and also the shielded part of the main pickup wire that goes to the switch/pot. The finish wire will be the hot wire. To "reverse" the wind, if necessary, you'll need to disconnect the leads coming off the coil and reverse them. Do it where they meet the coaxial wire, not at the pickup end.

Hope that makes sense.
 

TyronicusRex

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I would see how close you can get by lowering the neck and raising the bridge. If the bridge doesn't have a metal plate, you could try adding one. Sometimes that helps with definition. But if you track down the cause of the OOP middle position, you may also find you get a boost on the bridge if it is a bad solder joint.
Good call. I've lowered the neck PU as far as I can, so I'd have to rout the cavity a little deeper. Actually, the 5th string pole piece is maybe stripped? It spins but doesn't get any lower.

I'll re-solder the whole thing as soon as I get that 470k resistor!
 

Happy Enchilada

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Linda Lou, my beloved thinline parscaster, has a P90 in the neck and a hot single coil in the bridge, and they play nice.

What I'd recommend here is get a different bridge pickup that's hotter (I like the Bootstrap "Pretzel," and you can buy it ala carte for around $25). Stick with 250K pots. Try a different tone cap (I use .033 Soviet surplus PIOs - 2 for $10 on Amazon). But first I'd make sure your wiring is kosher.

1661532494568.jpeg


That's what we did on Linda Lou, and I get all the P90 goodness out of her neck and plenty of power out of the bridge. The neck P90 is Bootstrap's "Mean" version, which pairs nicely with the "Pretzel" hot bridge.

Good Luck!
 

TyronicusRex

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Linda Lou, my beloved thinline parscaster, has a P90 in the neck and a hot single coil in the bridge, and they play nice.

What I'd recommend here is get a different bridge pickup that's hotter (I like the Bootstrap "Pretzel," and you can buy it ala carte for around $25). Stick with 250K pots. Try a different tone cap (I use .033 Soviet surplus PIOs - 2 for $10 on Amazon). But first I'd make sure your wiring is kosher.

View attachment 1021378

That's what we did on Linda Lou, and I get all the P90 goodness out of her neck and plenty of power out of the bridge. The neck P90 is Bootstrap's "Mean" version, which pairs nicely with the "Pretzel" hot bridge.

Good Luck!
Bootstrap is new to me. Hard to argue with that price for alnico pups, if they're good.
 

TyronicusRex

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I finished re-wiring La Partida, using a 470k resistor and the diagrams from https://sixstringsupplies.co.uk/. (Their videos are great for a hack like me.)

The sound balance does seem to be a little better between neck and bridge, but it definitely sounds out of phase in the middle. Is there a good solution, other than getting a new PU with the right polarity/wind?
 

cousinpaul

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A Tex Mex would be a good call. There's no base plate. You could swap its two leads and correct the out of phase. Just remember to groumd the strings.

9k sounds like your P-90 might might be a bridge pickup. You might find a P-90 neck pickup that's not wound so hot. Something in the 7k range would be easier to mate with the tele bridge.
 
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