It is currently Mon Mar 16, 2020 1:02 pm

All times are UTC - 7 hours



Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next
Author Message
Post subject: loud hum from newly wired pickguard
Posted: Sat Jul 21, 2012 9:10 am
Offline
Hobbyist
Hobbyist

Joined: Wed Mar 14, 2012 9:13 am
Posts: 15
I wired up a new pickguard with Texas specials, new CTS 250K ohm pots, new Fender 5 way switch, aluminum shield (57 style) and cloth 22 ga. wire. It is wired as per Fender's drawing for SRV guitar with .047 uF cap. When I plug it in the amp all I hear is a loud hum. I checked the amp with another guitar and cable, both worked fine. I bench tested the pickguard out of the guitar with the jack soldered to it and noticed that when I move it around or have my hand close to tone pots the hum changes tone. ( I am standing on a rubber mat). I have removed the aluminum shield and added ground wires between the pots (no difference). Grounded the 3rd. prong onT1 (no hum with volume at 10 but as soon as I moved it to 8 and below it returned) tried grounding the 3rd prong on T2 (no difference), unsoldered these since they are not shown soldered in the drawings. All my pickup grounds and jack ground are soldered to the volume pot with the 3rd prong soldered to the case. I have checked and double checked the wiring and connections. I must admit I am stumped as to the cause of this annoying noise. Any help would be appreciated. Thanks!


Top
Profile
Fender Play Winter Sale 2020
Post subject: Re: loud hum from newly wired pickguard
Posted: Sat Jul 21, 2012 11:05 am
Offline
Rock Star
Rock Star
User avatar

Joined: Tue Jul 24, 2007 7:33 am
Posts: 8461
Location: Mars, the angry red planet.
ironhoss wrote:
I wired up a new pickguard with Texas specials, new CTS 250K ohm pots, new Fender 5 way switch, aluminum shield (57 style) and cloth 22 ga. wire. It is wired as per Fender's drawing for SRV guitar with .047 uF cap. When I plug it in the amp all I hear is a loud hum. I checked the amp with another guitar and cable, both worked fine. I bench tested the pickguard out of the guitar with the jack soldered to it and noticed that when I move it around or have my hand close to tone pots the hum changes tone. ( I am standing on a rubber mat). I have removed the aluminum shield and added ground wires between the pots (no difference). Grounded the 3rd. prong onT1 (no hum with volume at 10 but as soon as I moved it to 8 and below it returned) tried grounding the 3rd prong on T2 (no difference), unsoldered these since they are not shown soldered in the drawings. All my pickup grounds and jack ground are soldered to the volume pot with the 3rd prong soldered to the case. I have checked and double checked the wiring and connections. I must admit I am stumped as to the cause of this annoying noise. Any help would be appreciated. Thanks!


Let us see some CLEAR pictures of what you've done.

_________________
You dig?


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sat Jul 21, 2012 12:01 pm
Offline
Amateur
Amateur

Joined: Fri Jun 22, 2007 6:19 am
Posts: 108
You have a ground issue. Get yourself a $10.00 meter and check all the connections for continuity.


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sat Jul 21, 2012 12:41 pm
Offline
Rock Star
Rock Star

Joined: Mon Apr 05, 2010 2:37 pm
Posts: 8708
Location: Natural Bridge, Virginia
ironhoss wrote:
I wired up a new pickguard with Texas specials, new CTS 250K ohm pots, new Fender 5 way switch, aluminum shield (57 style) and cloth 22 ga. wire. It is wired as per Fender's drawing for SRV guitar with .047 uF cap. When I plug it in the amp all I hear is a loud hum. I checked the amp with another guitar and cable, both worked fine. I bench tested the pickguard out of the guitar with the jack soldered to it and noticed that when I move it around or have my hand close to tone pots the hum changes tone. ( I am standing on a rubber mat). I have removed the aluminum shield and added ground wires between the pots (no difference). Grounded the 3rd. prong onT1 (no hum with volume at 10 but as soon as I moved it to 8 and below it returned) tried grounding the 3rd prong on T2 (no difference), unsoldered these since they are not shown soldered in the drawings. All my pickup grounds and jack ground are soldered to the volume pot with the 3rd prong soldered to the case. I have checked and double checked the wiring and connections. I must admit I am stumped as to the cause of this annoying noise. Any help would be appreciated. Thanks!


The only pot lug that should be grounded is the emptly lug on the volume control. I don't see anywhere mentioned that you ran a ground wire to the body and a ground wire to the trem claw as shown in the schematic. If you are testing the pickguard outside of the guitar and do not have these two grounds connected, of course it will hum. I test all pickguard wiring with the pickguard installed in the guitar and all ground wires properly connected. Even with everything installed and grounded, you will still get 60 Hz hum if you are not touching metal on the guitar. That's a fact of life with single coil pickups.

_________________
Bill

Image


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sat Jul 21, 2012 4:14 pm
Offline
Professional Musician
Professional Musician
User avatar

Joined: Sun Feb 15, 2009 3:52 pm
Posts: 2005
ironhoss wrote:
I wired up a new pickguard with Texas specials, new CTS 250K ohm pots, new Fender 5 way switch, aluminum shield (57 style) and cloth 22 ga. wire. It is wired as per Fender's drawing for SRV guitar with .047 uF cap. When I plug it in the amp all I hear is a loud hum. I checked the amp with another guitar and cable, both worked fine. I bench tested the pickguard out of the guitar with the jack soldered to it and noticed that when I move it around or have my hand close to tone pots the hum changes tone. ( I am standing on a rubber mat). I have removed the aluminum shield and added ground wires between the pots (no difference). Grounded the 3rd. prong onT1 (no hum with volume at 10 but as soon as I moved it to 8 and below it returned) tried grounding the 3rd prong on T2 (no difference), unsoldered these since they are not shown soldered in the drawings. All my pickup grounds and jack ground are soldered to the volume pot with the 3rd prong soldered to the case. I have checked and double checked the wiring and connections. I must admit I am stumped as to the cause of this annoying noise. Any help would be appreciated. Thanks!



Do you have flouresents over you bench? What else is on your bench while testing?

_________________
-T

"You can't spend what you ain't got, you can't lose what you ain't never had" ~ McKinley Morganfield


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sat Jul 21, 2012 5:57 pm
Offline
Aspiring Musician
Aspiring Musician
User avatar

Joined: Sun Apr 06, 2008 12:07 pm
Posts: 383
Is your bridge grounded?
Does the hum disappear when you touch the bridge?


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sun Jul 22, 2012 8:06 am
Offline
Hobbyist
Hobbyist

Joined: Wed Mar 14, 2012 9:13 am
Posts: 15
Martian wrote:
Let us see some CLEAR pictures of what you've done.


As soon as I figure out how to do that. I guess I have to open an account at one of the image hosting sites.


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sun Jul 22, 2012 8:19 am
Offline
Hobbyist
Hobbyist

Joined: Wed Mar 14, 2012 9:13 am
Posts: 15
91Stratplayer wrote:
You have a ground issue. Get yourself a $10.00 meter and check all the connections for continuity.


Thanks for the reply!
I checked all the grounds for continuity to the output jack ground, all checked out fine. The cavity is painted with conductive shielding paint with a copper foil link to the aluminum plate under the pots. The tremolo is grounded to the pots. I also checked the ohm reading of my pickups and traced them through the 5 way switch to the pots and to the output jack. All readings were within the specs that I originally took of each pickup.


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sun Jul 22, 2012 8:31 am
Offline
Hobbyist
Hobbyist

Joined: Wed Mar 14, 2012 9:13 am
Posts: 15
bluesky636 wrote:
The only pot lug that should be grounded is the emptly lug on the volume control. I don't see anywhere mentioned that you ran a ground wire to the body and a ground wire to the trem claw as shown in the schematic. If you are testing the pickguard outside of the guitar and do not have these two grounds connected, of course it will hum. I test all pickguard wiring with the pickguard installed in the guitar and all ground wires properly connected. Even with everything installed and grounded, you will still get 60 Hz hum if you are not touching metal on the guitar. That's a fact of life with single coil pickups.


Thanks for the input!
The only lug I have grounded is on the volume pot. I reassembled the pickguard and body. Soldered the tremolo ground to the pots, the body is grounded to the aluminum plate under the pots via a copper strip ( I checked for continuity to the output jack). When I touch the bridge the hum decreases but is still there!


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sun Jul 22, 2012 8:38 am
Offline
Hobbyist
Hobbyist

Joined: Wed Mar 14, 2012 9:13 am
Posts: 15
tyronne wrote:
Do you have flouresents over you bench? What else is on your bench while testing?


Thanks for the reply!
I have a 4 ft. 4 bulb fixture in the ceiling above me, nothing running nearby or on the bench. I even shut the lights of but the hum is still there.


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sun Jul 22, 2012 8:44 am
Offline
Rock Star
Rock Star

Joined: Mon Apr 05, 2010 2:37 pm
Posts: 8708
Location: Natural Bridge, Virginia
ironhoss wrote:
bluesky636 wrote:
The only pot lug that should be grounded is the emptly lug on the volume control. I don't see anywhere mentioned that you ran a ground wire to the body and a ground wire to the trem claw as shown in the schematic. If you are testing the pickguard outside of the guitar and do not have these two grounds connected, of course it will hum. I test all pickguard wiring with the pickguard installed in the guitar and all ground wires properly connected. Even with everything installed and grounded, you will still get 60 Hz hum if you are not touching metal on the guitar. That's a fact of life with single coil pickups.


Thanks for the input!
The only lug I have grounded is on the volume pot. I reassembled the pickguard and body. Soldered the tremolo ground to the pots, the body is grounded to the aluminum plate under the pots via a copper strip ( I checked for continuity to the output jack). When I touch the bridge the hum decreases but is still there!


The body cavity should also be grounded directly to the back of the pot with all the other grounds. All grounds should be at one location (typically the volume pot) or to the volume pot and one tone pot with a heavy wire linking them. Do not run a ground to the shield plate.

_________________
Bill

Image


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Sun Jul 22, 2012 8:52 am
Offline
Hobbyist
Hobbyist

Joined: Wed Mar 14, 2012 9:13 am
Posts: 15
Guitarist1983 wrote:
Is your bridge grounded?
Does the hum disappear when you touch the bridge?


Thanks for the reply!
The tremolo clay is grounded to the pots. I checked for continuity from the bridge to the casing of the output jack and it shows it is grounded. When I touch the bridge the hum decreases but is still audible.


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Mon Jul 23, 2012 7:38 am
Offline
Hobbyist
Hobbyist

Joined: Wed Mar 14, 2012 9:13 am
Posts: 15
To-day I replaced the output wires running from the volume pot to the output jack with a single conductor with braided shield wire. Also I covered the back of the pickguard completly with conductive copper tape. The hum is reduced to being very faint, probably just the nature of single coils. This is the first Strat I have built with passive pickups since the other one I own has active (Powerhouse Strat) so I have nothing to compare it to. Thats where this board plays a big roll in keeping us thinking to solve our own problems, thanks to each of you that contributed! This board rocks!


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Mon Jul 23, 2012 7:55 am
Offline
Professional Musician
Professional Musician
User avatar

Joined: Sun Feb 15, 2009 3:52 pm
Posts: 2005
Hmmm...seems like overkill to reduce the hum that much but I don't know the environment you are playing in which can create issues too.

Glad you were able to reduce it to manageable levels.

_________________
-T

"You can't spend what you ain't got, you can't lose what you ain't never had" ~ McKinley Morganfield


Top
Profile
Post subject: Re: loud hum from newly wired pickguard
Posted: Tue Jul 24, 2012 8:10 am
Offline
Hobbyist
Hobbyist

Joined: Wed Mar 14, 2012 9:13 am
Posts: 15
tyronne wrote:
Hmmm...seems like overkill to reduce the hum that much but I don't know the environment you are playing in which can create issues too.

Glad you were able to reduce it to manageable levels.


Thanks tyronne, I was ready to try anything at that point. The only difference with my setup and the SRV wiring diagram was the full shield on the back of the pickguard. I am not sure which of the two fixes I did cured the problem (shield or wire change) but just glad it worked. Strung it up to-day played away, sounds great.


Top
Profile
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Go to page 1, 2  Next

All times are UTC - 7 hours

Fender Play Winter Sale 2020

Who is online

Users browsing this forum: No registered users and 1 guest


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to: