Dimarzio noiseless single - neck hum?

[GuitarStv]

I just wired up a set of Dimarzio single coils - Injector neck, Area 67 middle, and Injector bridge. They all make a loud noise in the correct switch position when I tap on them. The volume knob works to turn the sound down and the tone knob works to make the taps sound duller. It's completely noiseless in B, M/B, and B positions. In the N/M position there's some 60 cycle hum, and the neck solo'd hums very loudly - just like a regular single coil, the hum changes depending on the direction the guitar is pointing.

I'm guessing that I've somehow screwed up the wiring, but am not sure how - it's just standard strat 1v, 2 tone wiring. Any ideas where I should be looking in the circuit to debug?

 

[jeremy]

im assuming that you only have one coil working on the neck pup if its humming so start there

 

[GuitarStv]

There are four wires on the back of the pickups - red/green are full length and black/white (about an inch long and taped together at the factory). I was getting the right resistance reading from the red/green wires but I guess I can start by cutting open the black/white and make sure they're connected properly.

 

[jeremy]

one coil not working is the first thing to check, but if the dck is right then maybe its something else. maybe a bad ground on that pup?

 

[GuitarStv]

one coil not working is the first thing to check, but if the dck is right then maybe its something else. maybe a bad ground on that pup?

Ground should be good I think. I twisted all three green wires from the pickups together and soldered them on the back of the volume pot, so if it was bad I'd expect that it would be bad for all of them.

I'll re-flow solder over the red wire from the neck on the switch though.

 

[GuitarStv]

Re-flowed solder on the neck pickup hot connection and then re-flowed solder over the grounds for the hell of it too. Cut apart the red/white wires and I'm getting a 6.68k and 1.55k reading on the two coils, then re-soldered and taped them back together. Still hums unfortunately.

I also tried disconnecting the neck tone pot from the switch in case that was somehow introducing the hum - no luck there either.

As far as I can see, there's only the green wire acting as ground on these pickups - no bare wires to worry about.

 

[Masta' C]

Is the neck pickup new? Can you do a warranty return?

 

[GuitarStv]

Is the neck pickup new? Can you do a warranty return?

Yes, it's new. I just bought it about three months ago. Unfortunately, the bridge pickup that I ordered at the same time was backordered and didn't come in until last week - which is why I didn't install before now. I'll try contacting the store I bought it from, but think it might be too late.

Edit - Yep, they won't take it back.

 

[GuitarStv]

Well, I've confirmed that it's the pickup. Pulled it out of my pickguard and wired it directly to the jack and it's noisy as fuck. Dammit.

 

[jeremy]

seems like bad pup?

 

[GuitarStv]

seems like bad pup?

Yeah, I guess so. It's weird, I don't get how it's bad. The magnets work, the upper and lower coils are unbroken. I guess the only thing left would be wrong winds or something?

 

[jeremy]

out of phase? you could try swapping wires

 

[GuitarStv]

out of phase? you could try swapping wires

Yep, I'm going to give that a try tonight. That's the only other thing I can think it could be.

 

[Hank-]

What happens if the injector neck is placed in the bridge position, give it a quick check. These pickups don't have a bare wire shield, if the cavity is unshielded then these hum once your fingers are off the strings. Although it seems like you have run into a bad pickup, still try it in the bridge spot wired to the bridge terminal of the switch, you may get lucky and it turns out to be the switch. Or it's RWRP but that wouldn't make it hum by itself.

 

[GuitarStv]

I wired the injector directly to a jack, and it was humming like crazy. Then I wired a regular humbucker directly to a jack and it was dead silent. It's definitely the pickup.

Swapping wires around last night to see if it was a phase issue with itself I wasn't able to get hum to stop. Near as I can figure the dummy coil (or the regular coil) must have the wrong wind on it and it's just not cancelling hum. Dimarzio apparently has a 5 year warranty in the US, so I'll try contacting them about it and see if it holds for Canada too.

 

[Teleplayer]

Swapping wires around last night to see if it was a phase issue with itself I wasn't able to get hum to stop. Near as I can figure the dummy coil (or the regular coil) must have the wrong wind on it and it's just not cancelling hum.

It is really odd. The DCR seems about right, so I'm not sure how they can create a humbucker that doesn't cancel hum unless the winding direction is wrong as you suggest.

 

[Bill Dennis]

Talk to Dimarzio directly if the store will not help you.

 

[GuitarStv]

Talk to Dimarzio directly if the store will not help you.

Yep, I did. They said that since the pickup is brand new, I can send it to them and they'll replace it.

 

[ErikH]

I was about to say, contact DiMarzio directly and tell them the situation. There’s a good chance they’ll take care of you on it since you just got it and it’s new. Sure enough, they’re doing just that. I’ve always had good experience with their support. And it’s usually Steve who replies.

 

[GuitarStv]

Replacement pickup has arrived and doesn't hum! I'll get everything wired up this weekend.