T-riffic pickup mismatch

[royaltyetc]

Hello,
Just found this forum after feeling so alone fooling around with the guitarnuts shielding and s-tastic/t-riffic projects (which are great)

I was hoping if someone could confirm my suspicion:

I have a tele that I have performed the t-riffic mod on. The neck pickup is a diMarzio twang king (about 6.2K I read somewhere) and the bridge is a seymour duncan quarter pounder (about 15K or so).

Positions 1 (neck) and 2 (neck and bridge in parallel out of phase) sound like full dependable tones. However, the remaining 3 settings all sound thin as if the bass has disappeared.

Particularly strange is the bridge pickup alone (setting 5) which sounds very "out of phase" and thin on the bass, even though I thought it was operating alone (without the other pickup)

I read somewhere that a mismatch where the two pickup impedence measurements differ by a factor of 2 or more will cause the lower impedance pickup to shunt signal from the higher impedance pickup and cause it to sound weak.

Does anybody think this is what my situation is? Or did I wire it like a macaca (political suicide word for monkey)?

Thanks to all,
Jon

[sumgai]

roy,

Hi, and to the forums.

While I'm not the guy to dispense exact help with your particular bridge pickup, but I can say that you're describing the classic symptoms of a mis-wiring job. But the QuarterPounder is a single coil pup, according to the website.

Unless you have the dual-output tap option. It now sounds like you do have such, because the only way for a pickup to sound thin all by itself is to be mis-wired. And that takes more than two wires to accomplish.

Of course the pup itself could be bad, even if you do think that Pos 2 (bridge and neck, oop) sounds good. That particular combo is meant to sound thin, so that's not a good guide to go by.

My advice is to first re-check your wiring job. If you just don't see anything wrong, have a friend look at it for you. A fresh pair of eyes, and all that.

HTH


sumgai

[UnklMickey]

hi Jon,


you can learn a lot, just by doing some resistance measurements, before you even take it apart.

connect your ohmmeter (shuddup, i don't wanna hear how you don't have one. just pay the $5 and buy one.) to the tip and sleeve of the cable.

in the 5 positions, according to the t-riffic layout and your estimates for the pickup resistances, you should read (approximately):


1 -- 6k -- Neck
2 -- 4.5k -- Neck+Bridge in Series and Out of Phase
3 -- 4.5k -- Neck+Bridge in Parallel
4 -- 21k -- Neck+Bridge in Series
5 -- 15k -- Bridge


how your measurements deviate from this, might give us a clue to your wiring errors.

(BTW the shuddup part was just for emphasis. no offense intended.)


unk

[ChrisK]

unk,

1 -- 6k -- Neck
2 -- 4.5k -- Neck+Bridge in Series and Out of Phase
3 -- 4.5k -- Neck+Bridge in Parallel
4 -- 21k -- Neck+Bridge in Series
5 -- 15k -- Bridge

1 -- 6k -- Neck
2 -- 21k -- Neck+Bridge in Series and Out of Phase
3 -- 4.3k -- Neck+Bridge in Parallel
4 -- 21k -- Neck+Bridge in Series
5 -- 15k -- Bridge

Maybe it's:

2 -- 4.3k -- Neck+Bridge in Parallel and Out of Phase

[UnklMickey]

thanks Chris,

Jon indicated #2 as being parallel, but i believe it is actually series.

so 21k should be about right.

also i shouldn't have written 4.5k

i should have written 4½ k

i don't want to imply too much accuracy until we determine the values of bridge only and neck only.



I FORGOT TO MENTION:

volume control at max for this test.

tone control doesn't matter.




unk

[royaltyetc]

unk thanks for the strategy for testing with the cable in. Well everybody, it looks like my nect PU is measuring about 6.2 K and the bridge is measuring a whopping 1 Meg.

Looks like the PU might be shot...it was used after all. I even unsoldered one of the leads to test the pickup alone. I'll probably pull it out and shoot it!

Thanks for the help and that diagnostic is really going to pay off. I was able to test a couple other guitars just to see if I was in the ball park just to make sure I wasn't hallucinating the 1M resistance.
Jon