Author Topic: Do I have a problem? (Read 7270 times)

Andy RV · « **on:** May 21, 2006, 02:31:01 PM »

Hey guys, This has been happening for a while and its about time I sort it out.

I get a hum when I'm not touching any metal parts on the guitar, When I touch anything metal (strings, switch, bridge ect) the Hum goes away.

I've read on a site that this is normal with guitars that have passive pickups? Surely it can't be normal, none of my other passive guitars have this problem....

If its not normal then I'm guessing its an earth/ gound cable that is wrong somewhere?

I've got a cable coming from the top of the volume pot to the spring claw, so it is correctly grounded, the arn't any cold solder joints, everything seems to be in the right place, So I'm lost, any idea's?

Elliot · « **Reply #1 on:** May 21, 2006, 03:10:56 PM »

Its a ground problem for sure, nowt to do with passive pickups. By touching the metal you are acting as the ground. I once put my pickup screws in wrong (they weren't shielded by their rubber jacket) and the same thing happened. It was just a case of re-screwing the pickups into place to make sure they sat properly in the jacket. Hey presto the hum went away.

_tom_ · « **Reply #2 on:** May 21, 2006, 03:57:30 PM »

Quote from: Elliot

Its a ground problem for sure, nowt to do with passive pickups. By touching the metal you are acting as the ground. I once put my pickup screws in wrong (they weren't shielded by their rubber jacket) and the same thing happened. It was just a case of re-screwing the pickups into place to make sure they sat properly in the jacket. Hey presto the hum went away.

Rubber jacket? what? No pickups on my guitars came with rubber jackets for the screws :?

Elliot · « **Reply #3 on:** May 22, 2006, 01:49:49 PM »

On Fender strats the pickup screws have something chewy that tastes like rubber - BKP give you silicone type jacket that is better quality but doesn't taste as good. The thing I am talking about is probably called something else to those in the know :D

indysmith · « **Reply #4 on:** May 22, 2006, 02:10:27 PM »

BKP didn't give me any silicon... none of my guitars have rubber jackets either

blue · « **Reply #5 on:** May 22, 2006, 02:22:48 PM »

there may not be a grounding problem with the guitar, when you touch the strings or metal parts, you're not grounding the guitar, it's grounding you! odd i know, but apparently true. you would generally tend to be touching the strings when you're playing ( :P ) so i've gotten into the habit of rolling the volume off when i stop playing.

of course, there may be a grounding problem...

hunter · « **Reply #6 on:** May 22, 2006, 02:41:05 PM »

I have the same issue, but only if I'm too close to my computer.

Is this hum anyhow location related?

Bainzy · « **Reply #7 on:** May 22, 2006, 03:02:08 PM »

The reason guitar wiring systems ground out the player is because a human acts like an antenna for interference. Ever wondered why you get a better TV signal when you force your mate to hold up the aerial?

Andy RV · « **Reply #8 on:** May 22, 2006, 03:15:01 PM »

I've just checked to see if it changes if I move somewhere else and it's the same.

Also I've just noticed that when I touch the tone or/ and the switch the hum increases.

Here's how I've wired the guitar.

The 1st tab on the Volume pot is bent upwards and soldered onto the top of the pot grounding it, then the wire with the resister is soldered onto that.

If you can see anything wrong please let me know.

blue · « **Reply #9 on:** May 22, 2006, 04:03:31 PM »

there's no earth on the tone pot and the switch. just put a wire across them to the back of your volume pot and that should solve it.

Andy RV · « **Reply #10 on:** May 22, 2006, 05:46:41 PM »

I've just done that and it stops the hum getting louder when I touch the tone and switch, but I still get some hum and a 'tapping' sound when I touch the strings, controls ect.

Muttley · « **Reply #11 on:** May 22, 2006, 05:50:02 PM »

Quote from: hunter

I have the same issue, but only if I'm too close to my computer.

Is this hum anyhow location related?

That's inteference from your CRT monitor most likely. Turn the monitor off and see if it stops.

This is why I want a flat-screen for my recording PC.

PhilKing · « **Reply #12 on:** May 22, 2006, 06:50:39 PM »

The cyan wire from the tone should go to the centre tab.

Bainzy · « **Reply #13 on:** May 22, 2006, 07:10:29 PM »

I've no idea why you've got a resistor attached to the tone control, and the idea of a tone control is to form a resistor/capacitor tone network so it should have a capacitor inbetween a lug and ground or between the volume pot and the input lug of the tone control.

Ignore the splitting switch in the diagram, but this is what it should look like:

Andy RV · « **Reply #14 on:** May 22, 2006, 07:31:18 PM »

Ok i've changed it so thats its the same as that Diagram, and I still have the same problem, i'll probaby just take it to the guitar shop tomorrow and get them to sort it out,