QP buzz

[95strat]

I just installed a Quarter Pound in my tele bridge last week and I'm getting a ton of buzz. When I touch the tone or volume knob it drops. I'm guess it has something to do with the grounding. I've got it soldered to the back of the volume pot.

Any idea what's causing this? I'll open it up and see if the solder joint looks cold, but I could have sworn I got the ground wire on there with a nice hot joint.

 

[Rich_S]

Re: QP buzz

Hmmm... doe the QP have a metal base plate? If not, you've probably lost your string ground connection. Most guitars have a wire from the common/shield to the bottom of the bridge. But I believe some Tele's don't have this string ground wire, because the negative bridge pickup lead connects to the pickup base plate, which connects to the bridge via the mounting screws.

Put in a pickup with a fiber base plate, and there goes your string ground.

I miss having a Quarter Pounder, it's a great pickup. I want to build another Tele, set up as a simple 2-knob Esquire: tapped QP bridge, volume, and spin-a-split. That would be a fun axe.

 

[Benjy_26]

Re: QP buzz

the QP does not have a baseplate. You need to run a wire from the back of the pot to the bridge.

 

[95strat]

Re: QP buzz

the QP does not have a baseplate. You need to run a wire from the back of the pot to the bridge.

What exactly do you mean by the bridge? To the pickup or just the bridge plate? And how do you solder to a chrome plate? Sorry for the ignorance. Thanks for the help.

 

[Benjy_26]

Re: QP buzz

Bridge plate. You don't need to solder to it, just put the bare wire under the bridge plate and clamp that plate down tight.

 

[95strat]

Re: QP buzz

Gotcha. Thanks Benjy!

 

[idsnowdog]

Re: QP buzz

The QP's are loud and prone to hum. You could add a grounded shield to the coils to reduce hum.

 

[95strat]

Re: QP buzz

The QP's are loud and prone to hum. You could add a grounded shield to the coils to reduce hum.

Sounds intriguing, but I have no clue what that is. Please enlighten me!

 

[idsnowdog]

Re: QP buzz

You put a foil shield around the coil that is grounded, the RFI is then sent to the ground and not the guitars circuitry. IIRC the QP's do have a cloth shield so you only need foil, solder and a ground wire. I have shielded a few single coils and it does reduce the amount of hum.

 

[95strat]

Re: QP buzz

You put a foil shield around the coil that is grounded, the RFI is then sent to the ground and not the guitars circuitry. IIRC the QP's do have a cloth shield so you only need foil, solder and a ground wire. I have shielded a few single coils and it does reduce the amount of hum.

Just wrap the foil around the outside of the cloth shield, run the wire from the foil to the volume pot? Sounds easy enough. Where can I get some foil?

 

[Benjy_26]

Re: QP buzz

Hobby shops are good places to look for foil.

 

[idsnowdog]

Re: QP buzz

Adhesive backed copper shielding foil would be the easiest to use and solder. You can find it at Carvin or Stewmac. Otherwise you could use aluminum adhesive backed flashing tape, but it is hard to solder.

 

[uOpt]

Re: QP buzz

Shield the cavity first.

Kitchen aluminium foil does fine hum-wise, it's just not that easy to work with.

 

[95strat]

Re: QP buzz

Should I just shield all cavities while I'm at it? I don't mind getting good shielding, but if aluminum foil works just as well I do that. I found an online tutorial.

And stick with copper for the QP...correct?

 

[uOpt]

Re: QP buzz

I think you don't even have grounded strings. That's the first step.

 

[95strat]

Re: QP buzz

I think you don't even have grounded strings. That's the first step.

True. But that will be taken care of if I ground to the bridge plate...correct?

 

[uOpt]

Re: QP buzz

Yeah, and it might be sufficient.

 

[95strat]

Re: QP buzz

Yeah, I'll start there and work toward the foil thing.

 

[95strat]

Re: QP buzz

Alright, got the bridge grounded and wow does that make it 1000 times better. I play at live tomorrow so we'll see if I'll take it a step further and shield the cavity.

Thanks for the help guys.