debugging a noisy guitar circuit: is this logic?

[cordura21]

I am going to rebuild a noisy strat circuit. I don't know what makes the noisy.

My theory is that if I go from the simplest circuit, and then begin adding components, at sometime I'll find the offending little bastard.

So I'm gonna start attaching one pickup to my amp cable, the red lead to the tip, and the white one to the sleeve.

My questions are:

1- should that work without noise, or doing this simple connection will bring noise too?
2- Shouldn't it make ground thru the sleeve, or should I put another ground (like the manufacturers, who use the bridge as ground)?
3- Can I make it and test it outside the guitar, or doing this brings more noise (being that it's not under the plastic case or the metal plate)?

Cheers, Andrés

 

[Fangar]

I am going to rebuild a noisy strat circuit. I don't know what makes the noisy.

My theory is that if I go from the simplest circuit, and then begin adding components, at sometime I'll find the offending little bastard.

So I'm gonna start attaching one pickup to my amp cable, the red lead to the tip, and the white one to the sleeve.

My questions are:

1- should that work without noise, or doing this simple connection will bring noise too?
2- Shouldn't it make ground thru the sleeve, or should I put another ground (like the manufacturers, who use the bridge as ground)?
3- Can I make it and test it outside the guitar, or doing this brings more noise (being that it's not under the plastic case or the metal plate)?

Cheers, Andrés

Andres,

Before you begin, you might want to get some specs and schematics as your questions hint that you may be in over your head. Not a slam, I would just like to see you have the best time you can.

Fangar

 

[cordura21]

good advice. I already have all the schematics. I am learning to do this, but the first one I assembled works fine (maybe it was luck).
It's also more of a thing I wanna know: if I just connect the pickup to the output, should that work without noise?

 

[Lopp]

Just connecting the pickup to the output will work if done correctly.

However, since it is a Strat with assumably single coils, I am curious if you get noise when the volume pot is at zero. In particular, single coils are noisey when compared to humbuckers. Also, there may be other sources of noise causing the problem. For example, a computer monitor can cause nasty noise problems. Also, interference in your house wiring can also cause noise. Furthermore, your amp be the culprit. Thus, there may be other sources of noise aside from your Strat wiring.

Then again, you may have already considered these factors and have definitely narrowed it down to your Strat wiring.

 

[cordura21]

you don't get noise when the volume pot is set to zero.

I considered everything else in the room, so I guess is the strat.
I have to say that this guitar seems very prone to catch buzz and hums from monitors, lights, etc... I have another one which is an exact copy, and it gets much less noise from the same sources.

 

[Even]

One huge and often overlooked consideration in electronics noise in a guitar is the cavity itself. Be sure to line the cavity that the pots go in with a copper base. You can pick up rolls or sheets of tape lined copper to stick to the entire routed cavity. Secondly, use either single strand wires or tin dip {pre solder the wire lengths) your wires.

 

[toyL]

...if your other "exact" guitar is wired the same and it is less susceptable to noise there is no real need to test further...or am I missing something?

 

[Clive Hugh]

www.guitarnuts.com

Try this site, they have a very good posting about shielding strats.

 

[cordura21]

...if your other "exact" guitar is wired the same and it is less susceptable to noise there is no real need to test further...or am I missing something?

No, I meant that when they were both working without the humm, one was less prone to make noise than the other.

 

[Fangar]

No, I meant that when they were both working without the humm, one was less prone to make noise than the other.

In that case cordura, I would lean towards the pickups as being of a lesser quality or more susceptible to interference. Single coils will often have ths problem over a traditional humbucker, or stacked humbucker for a traditional fit.

Fangar