Installing new pickups.. need help with hum...

Jim_H

Junior Member
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Thanks in advance for any assistance here.

I'm fairly new to the electronics side of things.

I purchased and installed a brand new set of Fender Vintage Noiseless pickups in a strat today. 
http://www.amazon.com/Fender-Vintage-Noiseless-Stratocaster-Pickups/dp/B0002E3D44/

Everything works well, except for one glaring issue, that I just can't seem to solve.  There is a significant hum.  It is almost completely eliminated if I touch my hand to any ground (bridge, jack plate, switch body, etc...).

The tone knobs don't seem to have any affect on the hum at all.  The volume changes the volume and the pitch (frequency?) of the hum, but it doesn't ever go away completely unless I touch a ground.

One thing that I should point out.  The kit came with three pots, two capacitors, and a resistor, and NO instructions!.  One of the pots was 1 Meg, and two were 500k.  The capacitors were standard fare 22k and 680k (pF?).  I wasn't sure what to do with the resistor or the 680k capacitor, so I just used the 22k on the neck tone pot as per the drawing.

Since there were no instructions,  I thought I'd play it safe and use a standard 5 way , 1 volume, 2 tone setup like this.
http://www.guitarelectronics.com/product/WDUSSS5L1201/Strat-Style-Guitar-Wiring-Diagram.html

I've double and triple checked everything.  I'm fairly certain my wiring is correct, and I have gone over all of the grounds with my ohm meter and everything is grounded. 

After getting the hum, and not being able to eliminate it, I started searching around the web and found an annotated review showing the resistor and  680k capacitor across two lugs on the volume pot "as per the instructions" (according to the amazon reviewer).  So I added these to my config and saw no change.

I triple checked the output jack lugs to make sure they weren't reversed, so at this point I'm stumped.

I have a very rudimentary understanding of how this stuff works.  I suspect there may be a short somewhere, either in the switch, or possibly with the 1 Meg volume pot (its just an uneducated hunch).

I have spare switches around, and some 250k pots.  I'd really like to see how these sound with the included 1meg pot, so I think I might try replacing the switch first.

It's late tonight, so I'm going to sleep, and will get back on this tomorrow.

If anyone has any suggestions, or can shed some light on this, I'd appreciate it.

Thanks,
Jim

Edit: I attached the picture from the Amazon review showing how the resistor and smaller capacitor are installed.  This is not my actual stuff...
 

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You have  a grounding issue. Something that you probably think is connected to ground isn't.
 
Ummm ... I had a similar issue sometime back.

Checked all wiring, and all was correct. But still hummed like yours sounds like.

Others will laugh at my fix ..... but it worked.
Shove a wire between the switch control casing, and send that to an earth.
 
Thanks for the replies!

I can't imagine I'm missing a ground connection.  I'll double check when I get to the shop this afternoon.  The switch body is definitely grounded ( I checked with the meter).

I think at this point either the switch or one of the pots is bad, and has a short to ground.


I'll be in the shop this afternoon, and check it all again. 
 
If its responding to you grounding out the circuit, it sounds like a cold joint. Just re-solder your grounds, make sure you have a nice roughed up surface to solder to and use a good quality flux core solder. I've had these issues before and usually revamping my grounds sorts it out. The other option is to re-wire your switch. Sometimes phase reversal and other such issues create hums with strat style 5 ways, albeit the time I had an issue with that was with one of the Suhr super switches that has about 20 contacts.

Good luck!
 
Thanks for the input everyone. 

I have to say that this has been the single most frustrating experience for me since I started working on my own guitars.

I have an American Deluxe Strat with this exact same set of pickups in it and it works beautifully.  I took the pickguard out and layed them side by side and compared everything.. tracing every wire, checking every ground with the meter...  Everything is *exactly* the same (except the hum).

I even tried swapping out the switch (no change) and the suspect 1Meg volume pot (no change). I then isolated each pickup individually to just the volume pot and got the same hum. 

I know it's not the cable or the rig, as the does not exist on other guitars or on the identically configured strat. 

I've wasted an entire weekend on this catastrophe, so I'm going to put it away for now.  I took the pickguard out of my American Deluxe into this new strat.  I'm going to site down and play for a few hours.

I'll get back to the madness after the frustration fades...
 
I put the (original series) Vintage Noiseless pups in my Strat about 6 years ago.  I'm not thrilled with the 1meg pot and I don't remember anything about a resistor.
Short of pulling off the strings & pickguard I can't really say, but it's got no hum to it.  I like them so much that I probably won't ever change them out.
If by strange coincidence I do break a string before you get it sorted I'd be happy to snap a shot 'under the hood' of my wiring.
 
Thanks Autobat, but don't worry about it.

Like I said, I have a set of these same pickups in an American Deluxe strat, that work perfectly.  They are the reason I decided to put them in this new strat.

I finally gave up and decided to do something else with what was left of my weekend. I did put the pickguard from my American Deluxe strat in this new one, and they work like a champ.  I'll figure out whats going with the new set one of these days, and put them into my old strat.

Thanks for everyone's input...

jim
 
Tried putting each individual pickup straight to the jack? You've included the volume pot every time, surely it's time to eliminate that now?
 
That's just it.. i did eliminate the volume pot.  I eliminated *everything* at some point. 

I think at this point, I'm just going to pull everything off and build the pickguard up from scratch. 

But not until I've had some fun doing other stuff (I finally finished a Bass project tonight that I'm really happy with).
 
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