Mustang bridge grounding

blacktaxi · Post by **blacktaxi** » Sun Nov 16, 2008 11:08 am

okay, stress-testing of my mustang shown that it (sadly) needs shielding and rewiring.
while i'm rather new to this and it still seems not very hard, there's one thing i need an advice with.

in the pots/jack cavity, there's a wire that comes from metal bridge postholder i guess. this one:

my question is: is there a way to replace it nicely? is it possible to have the thing wired without grounding bridge/strings?
i really want to do all this rewiring/shielding once and nice, so i won't have to dismount the pickguard for a long time.

Post by **Mike** » Sun Nov 16, 2008 11:17 am

What?

You need to have the bridge and strings grounded or it will hum like a bastard. If you're adding sheilding to reduce hum then by removing the bridge ground you will be making things MUCH worse, shielding or otherwise. Just make a hole in your shielding and pass the wire through and solder it to the shielding. Make sure you connect the shielding to the rest of the grounds in the circuit.

blacktaxi · Post by **blacktaxi** » Sun Nov 16, 2008 4:49 pm

Mike wrote:What?

You need to have the bridge and strings grounded or it will hum like a bastard. If you're adding sheilding to reduce hum then by removing the bridge ground you will be making things MUCH worse, shielding or otherwise. Just make a hole in your shielding and pass the wire through and solder it to the shielding. Make sure you connect the shielding to the rest of the grounds in the circuit.

right. i've just found out how to replace the wire. if you hold the body faced down the postholders just fall out.
now, i know that bridge (and hence strings) are usually grounded on guitars to reduce hum, but when you lift off your hands and don't touch any metal parts, what's the effect of it? on my 'stang, when you don't touch anything metal, there was significant hum increase. does that mean anything?

Post by **Mike** » Sun Nov 16, 2008 5:05 pm

It means they're not grounded properly. You need to check the bridge cups are grounded to the rest of the grounds and that the bridge is making electrical contact with the cups (no tape on it)

blacktaxi · Post by **blacktaxi** » Tue Nov 18, 2008 8:38 am

okay, i did it.

i put it apart and stick it with aluminium tape all over the place.

made stitches commutate, and sealed with insulation tape. triple checked everything, checked like 30 random pairs of points for commutation and contacted pickup cavity shielding with pickguard and controls cavity with control plate. everything seems solid. while i were at it, i put another single coils there just out of curiosity, one texas special into bridge and one MIM strat low-output into neck. these are microfonic as shit so i think i'm gonna put original back...

well, anyway, moving to the point. this all things i did significantly reduced hum levels. before, there was a difference if i touch the strings (when not touching there was more hum). now, it's gone, and also, volume pot at half doesn't give 50Hz hum anymore! this all looks nice, but is this good?? not like i'm insane or something

i ask just because every guitar i had was humming at half volume.
oh, and also, before this shielding, when both pickups were off it was buzzing, and now it doesn't. is that good also?

if this isn't good, what could i do wrong?

Post by **Mike** » Tue Nov 18, 2008 8:43 am

blacktaxi wrote:before this shielding, when both pickups were off it was buzzing, and now it doesn't. is that good also?

That means before you did the work, the grounding was broken and now it is fixed. It has nothing to do with the shielding. But yes it is good. It seems that now your guitar is functioning as it should.

blacktaxi · Post by **blacktaxi** » Tue Nov 18, 2008 8:49 am

Mike wrote:
blacktaxi wrote:before this shielding, when both pickups were off it was buzzing, and now it doesn't. is that good also?
That means before you did the work, the grounding was broken and now it is fixed. It has nothing to do with the shielding. But yes it is good. It seems that now your guitar is functioning as it should.

awesome! thanks.

blacktaxi · Post by **blacktaxi** » Mon Nov 24, 2008 9:31 am

yesterday i disassembled my mustang once more...

i rewired it a bit to make earthing star-style, CBA to replace all wires, i think i'll do it some time later..
instead of screwing ground wires to the body like people on the internetz suggest, i just solidly soldered them to bridge grounding wire, the one that is held by bridge cup. now, controls cavity shielding is connected with common ground through control plate, which is in turn connected through pots (or the input jack? now i'm not sure on this one, but i checked it with multimeter and there's a contact..

). i then put an small overlap of aluminium foil from control cavity to bridge pickup cavity, which makes pickguard foil earthed when screwed down, and which in turn makes pickup cavity shielding earthed.

hope at least tiny bit of that is understandable... well, anyway - the shit works! i borrowed friend's metalzone for a couple-a-days, and with both pickups in phase, there's no HUM and NOISE, with the fucking metalzone at MAX! this is just awesome... i can hear the sound when i just touch the neck or body, but no noise.

however, i think i've became a noiseless-nazi a bit, because when only one pickup is on, there's the noise, and AFAIK you can't get rid of that. well, that's leaning to humbucking pickups, but i hope i won't go that far.

Post by **Mike** » Mon Nov 24, 2008 9:36 am

Well done, it sounds like you've absolutely nailed it. Everything should be grounded together.

Pickup, pot, jack and switch grounds, bridge cups, shielding.

robroe · Post by **robroe** » Mon Nov 24, 2008 1:29 pm

all my guitars hum like all fucking hell. even the humbuckers hum. ive just gotten used to playing in a 5' x 7' tiny room with a computer, a monitor, a PA, 2 amps and all sorts of other ill shit plugged into the wall all at once.

if i use a mega long lead and walk out into the living room everything stops humming.

blacktaxi · Post by **blacktaxi** » Mon Nov 24, 2008 1:46 pm

robroe wrote:all my guitars hum like all fucking hell. even the humbuckers hum. ive just gotten used to playing in a 5' x 7' tiny room with a computer, a monitor, a PA, 2 amps and all sorts of other ill shit plugged into the wall all at once.

if i use a mega long lead and walk out into the living room everything stops humming.

if your guitars are in stock configuration, take your time and shield/rewire your guitars, or ask someone to do it for you. really helped me... it took very much time, but it's worth it. humbuckers shouldn't hum.
i had this humming all the time since i got my first electric, and always was wondering how do they make them sound so clear on recordings. if your guitars are already nicely wired, then maybe the problem lies within amp earthing, or some powerful electric device running in that room, or in the room next to it.

btw, computer does nice amount of hum. i have a laptop now, and instead it does a good amount of hisssssss if i sit close to it, which is probably even worse.

robroe · Post by **robroe** » Mon Nov 24, 2008 1:52 pm

exactly my point. my room here with all my equimpment is so small i am constantly playing very close to the computer so i get buzzing from it.

it also depends on how i possition my PA cabinets. right now they are facing my guitar amp creating some cazy out of phase sounds when i have cd's plying thru it and me playing guitar thru the amp at the same time.

a couple of times i have had them actually cancel each other out so much that i thought i unplugged every thing, tripped on a wire, or blew a fuse or something. but its just the sound waves hitting each other head on and phasing out.

to say the least its an interesting room to play in.

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Bacchus · Post by **Bacchus** » Tue Nov 25, 2008 9:34 am

I always find that turning off the monitor stop shum when I'm playing with the computer on.