Grounding - Bzzzzz

30yroldpig · #1 04-21-2002, 11:41 PM

Hey guys I am having one hell of a time trying to figure out how to get rid of this annoying buzz.

First off As most of you know I have completed a mod on my UV777BK which consisted of replacing the mirrored pickguard with a plain simple black one and removing the single coil.

When I removed the single coil I accidentally unsoldered some connections and have only till now gotten to fixing it (I live in an appartment and my Half-Stack is at my parents...)

http://www.jemsite.com/tech/img/t_wd_777.gif is the diagram that I refered to, minus the single coil.

I know that this is a grounding issue because the second I touch any metal component, the buzz dissapears. Problem is I can't for the life of me figure out what else to do! I have one ground wire going to the trem claw and the other going to the screw under the 5 way selector switch. Any Ideas?

Project Guitar · #2 04-22-2002, 04:04 AM

Ok a couple ideas for you to look into. First off that second wire going under the five way, is that the wire that normally would end up being screwed into the body itself under the single coil right in the middle of the electrostatic sheilding paint? becaue the orginal pick guard probably had a sheild coating which grounded to the sheilding paint in the cavity.

The other thing you might want to check is to be sure you don't have the wires reversed on the output jack (simple but happens). If it's a three lug the hot wire should go to the medium length lug the other two (longer and shorter) are the grounds. If it's a Mono Jack chances are the short lug is the hot wire.

Other than that I would just say recheck the wiring, chances are the problem is stearing you in the face and you've over looked it...

30yroldpig · #3 04-22-2002, 12:54 PM

Quote:

becalvert on 3:04 am on April 22, 2002
Ok a couple ideas for you to look into. First off that second wire going under the five way, is that the wire that normally would end up being screwed into the body itself under the single coil right in the middle of the electrostatic sheilding paint? becaue the orginal pick guard probably had a sheild coating which grounded to the sheilding paint in the cavity.

Damn it I completely omitted to check that!!! The entire original UV pickguard is shield coated !!!! That's probably my problem :doh: :doh: :doh:

As for the second ground wire It is screwed into the body itself but in no way is it near the single coil. I never touched that. BTW this has been a great experience. Whoever soldered this guitar at the factory did a s&*t job....

Thanks for your help Becalvert, I'll post to let you know!!

Pat

30yroldpig · #4 04-23-2002, 11:45 AM

Well I bought the shielding paint (36$!!!!) but before applying it, I tried something else. I glued some aluminium foil to the back of the pick-guard. I can't really tell if it's doing anything yet though cause my main ground problems are still there...I get a nasty hum when I touch the knobs...

I'll keeps yalls posted.

30yroldpig · #5 04-24-2002, 12:50 PM

Well, the buzz is gone and most of the p-ups are working just fine. Problem is now when I touch the p-ups there is a buzz.

You know..I fix these kinds of problems regularly at the studio and I can't, for the life of me, figure out what the hell I am doing wrong :idunno::idunno::idunno:!!!!

Gresh · #6 04-25-2002, 04:03 PM

Hey Pat,

I am having a similar issue with my UV and it is totally stock. *My buzzing seems to come only when the guitar is positioned like it were laying flat, as on a table. *When holding the guitar in a playing position, the buzz goes away. *Tilt the body away from you, and it comes back. *Ground wire in the trem cavity is fine...haven't pulled off the pickguard to look inside yet...

You got any ideas before I take the sucker apart??

toshiro · #7 04-25-2002, 09:25 PM

Gresh:

Sounds to me like you have 'ambient' hum.. The guitar is picking this up from something else, which is why it goes away when you move to a certain position. Florecent lights, computer monitors, TVs, etc can cause this..

Just for fun, worst case of hum I've ever worked on was a double-neck acoustic-electric Washburn.. Replaced wires, new preamp, everything we could think of.. After the last repair, he returned with it again, and I about freaked.. Took it into the back room, where there were no hum-causeing items, plugged it in, and no hum.. Turns out the wireing in his house was causeing it, probably from the beginning.. Ouch.

Gresh · #8 04-26-2002, 12:04 AM

Man, how expensive was that lesson!?!?!?

I will check it out in a different location, but my 2027 is dead quiet at exactly the same spot which leads me to believe that it is something internal to the guitar.

30yroldpig · #9 04-27-2002, 12:25 AM

I would say to not take anything apart. Ha hell if you can take an up-close picture of theinnards in your UV and e-mail em to me!!!

Nothing is working right now...

toshiro · #10 04-27-2002, 02:56 AM

Expensive? Don't really knopw, as he got the pre-amp himself from Washburn, hopefully he got it under warrenty or something..

We don't usually charge labor if something comes back in within a few weeks of it going out(unless there's something new wrong), so his bills weren't to bad.. It was more a case of him getting irate with us, and me getting mad at his guitar.. Then, of course, he found out it wasn't the guitar, or my working on it, but his house.. Made me feel a bit better, a was going insane trying to figure out what was wrong.. It wasn't humming in the store that much, even in the beginnin,g not near as bad as he explained.. Oh well, case closed on that one.

Yeah, check that thing out in other environments before tearing it apart.. The only real thing that can be done about 'abient' hum is shielding.. And while the paint is nice, I still prefer the copper-foil-tape method.

30yroldpig · #11 04-27-2002, 12:10 PM

So does anybody have any wiring diagramms for 2 hums, 1 vol, 1 tone and a 5 way switch? I've been looking around, found some stuff that GhesQ posted but nothing worked. Right now I am using the JEM777 wiring diagram minus the single coil p-up (http://www.jemsite.com/tech/img/t_wd_777.gif)

It's just not happening, I am going something wrong:angryfire: ...been spending all my spare time on this. I think I am going to try installing a 3 way..may be a little easier.

toshiro · #12 04-28-2002, 01:25 AM

This is what I use on my H-H guitars, works really well, and is completely humcancelling.

Only problem is that it needs a multipole 5-way(read: Megaswitch).

http://www.dimarzio.com/w_d_3_1.html

30yroldpig · #13 04-28-2002, 12:50 PM

I have seen that web site and that is exasctly what I need. I think I am gonna go out and buy one. What exactly is the difference between a 5 way multipole and the ones found in the UV7BK?

toshiro · #14 04-28-2002, 06:04 PM

I think the UV's have two sets of 4, 3 plus output per side, contacts on the switch. The notch postions combine the neck-middle/bridge middle automatically, inside the switch. The multipole has 4 sets of 6, 5 plus one output per set, contacts on it.. This doesn't combine anything automatically, so you have to wire it to use more than one pickup in a position. They give you 4 sets of contacts, so you can get tapping, and other extra things.. I know, bad desciption.

The reason for the megaswitch, is that you can pick and choose what is on in each position. It's pain in the butt to wire from scratch, without a diagram, but you can pretty much do anything with one. Having a diagram makes it easy, though. *:biggrin:

30yroldpig · #15 04-28-2002, 09:46 PM

Quote:

toshiro on 5:04 pm on April 28, 2002
Having a diagram makes it easy, though. *:biggrin:

Amen to that. So the dimarzio site's diagram works just fine then? I want position 1 to be Neck 2-3-4 to be off and 5 for bridge.