Mystery Hum from SH6 distortion put in Blacktop Strat (HH) bridge

[dgvro]

I recently got a used Fender Blacktop HH Strat. I shielded the cavities with nickel shielding paint and I put a different pickup in the bridge but am now getting BIG hum/noise from the bridge pickup. I don't think the shielding messed anything up because the neck humbucker is very noise-free. but the bridge humbucker... it sounds almost like a singlecoil in terms of noise, but I wired it up foolproof by literally just connecting my new humbucker's 4 cables (well, 5 including bare wire) to a portion of the old pickups 4 cables I left in place - basically I didn't have to touch any connections on the pots and switch etc, it was just connecting 4 cables to 4 cables.

The original stock bridge humbucker on the Strat wasn't this noisy, not at all. My new one is a littler more high output (Duncan Distortion SH6) but I have had the same duncan SH6 in a different guitar up until now and it was the most noise-free guitar I had, the pup was perfect.

I have even tried a different, 3rd pickup (Duncan SH15, "Alternative 8") in the guitar wired up exactly as stock again and still get the insane hum/noise.

Here is a comparison audio between:
https://drive.google.com/file/d/0B2Jr81F-onCoU0tVc2JrTDYwQlk/view
1. a guitar of mine (Squier '51, shouldn't be a million miles off from a Blacktop, and even then you'd expect to sound worse rather than better) with a BKP Miracle Man in it that has somewhat normal amounts of hum (though still more noise than my Duncan Distortion used to have in another guitar)
2. The new blacktop Strat with the Duncan SH6 in it (full bridge humbucker position)


You can hear the noise kick in half way through when the audio changes to the 2nd pickup. Does anyone recognise the kind of noise I'm getting and what the cause of it might be? My other guitars haven't been like this at all under the exact same recording environment.


- the Strat's pickguard was already shielded with aluminum foil stuck to it.
- I used the attached image below to co-ordinate connecting the Duncan pickup wires to the stems of the stock Fender pickup left wired up to the pots etc:

 

[dgvro]

Re: Mystery Hum from SH6 distortion put in Blacktop Strat (HH) bridge

Also, I feel like the SH6/distortion, aside from the noise, is a little bit wimpier in this guitar than in the deluxe style tele I had it in before. Could this be down to a capacitor/tone pot that saps a bit more output on the high frequencies? Is there a handy mod anyone would recommend to the stock Blacktop Strat pots/caps to give the bridge pup a bit more teeth?

I understand the stock capacitor is like 0.047uf so I might just swap that out for whatever I had in my old tele where the SH6 sounded beefier (maybe it was a .022uf?)

 

[daenius]

Re: Mystery Hum from SH6 distortion put in Blacktop Strat (HH) bridge

That's CERTAINLY not expected of a Distortion!
Do you happen to know what value of the volume and tone pots are? If they're 500k, then the cap and pots are not likely the culprit here.

You also tried another Duncan pickup so unless they're both broken (unlikely), this seems like something else.

Take a multimeter and measure the pickup, if the values look good, it could be the switch that's busted.

You might just want to check how Fender's stock wiring is, because depends on how they wire their harness, it may require modifications for the Duncan's to work. Notice that the diagram can only tell you what the Duncan's series link is and can't guarantee that the same type of wiring applies to other brands.

Like I said check the switch to make sure it's not broken and that it's wired correctly: make sure that when you're in the bridge position setting, the switch is sending the black hot to the pot input, and that it has red and white soldered together, and that bare and green are both going to a ground somewhere

 

[Darg1911]

Re: Mystery Hum from SH6 distortion put in Blacktop Strat (HH) bridge

Forget the wire splicing that you did and just bite the bullet and wire the humbucker directly to the controls. In so doing, you would eliminate the already existing old wiring plus any poor solder joints from being the soruce of the problem ... assuming you are capable enough with a soldering iron of course.

 

[dgvro]

Re: Mystery Hum from SH6 distortion put in Blacktop Strat (HH) bridge

I've fixed it! 'Bucker is dead quiet now when not playing any strings.

What was wrong, in order of probability, because it may have been either one or both:

- the way the above cable colour codes guide translates duncan to fender had me wiring up my duncan cables to unexpected fender cables, but I didn't question it at the time since I knew the original pickup worked great just as it was installed. I don't know if the fender bit of the guide is just wrong (I've used it enough times to know it's correct for Duncans) or the original humbucker in the guitar was just wired up weird such that doing a like-for-like substitution of the cables meant my new humbucker was either in a weird polarity (surely wouldn't cause hum when just on bucker-only position though?) or somehow only using 1 coil.
- I re-did some tidier solder connections instead of the ones from yesterday. It's possible one of them involving a ground cable cleaned up the noise too


Thanks a million for the help. Now to investigate why my other guitar with the Bareknuckle in it sounds noisier than the SH6!

 

[Mincer]

Re: Mystery Hum from SH6 distortion put in Blacktop Strat (HH) bridge

We are happy you figured it out! Tracking down hum problems can be very frustrating. It gets worse for me as I work on it longer and get more tired.