Why is my wiring always so noisy?

mynameistrouble

I like to do my own electronics, and I’ve got pretty adept with a soldering iron such that my joints resemble neat shiny things rather than awful brown-tinged sloppy messes.

However, without fail when i have had a go at a guitar’s innards, it becomes way noisier. Everything is properly grounded, but if i take my hands off everything there is a very audible hum that wasn’t there pre-meddling.

What is the likely cause of this? Unsuitable wire? It’s the fact that I manage to make previously quiet wiring noisy that i find so frustrating - I recently changed the volume pots in my Cole Clark (alpha, same brand as the existing ones) and the only other changes were a few very short replacement bits of wire. It was just what i had to hand, stuff from maplin. Much noisier than before.

Any pointers much appreciated!

ICBM

Did you connect the pot casing to ground?

If it’s much noisier then it’s a certainty that you haven’t connected a ground or shielding correctly.

Funkfingers

What resistance values were the Alpha pots that you removed and the ones that you installed? 

mynameistrouble

ICBM said:

Did you connect the pot casing to ground?

If it’s much noisier then it’s a certainty that you haven’t connected a ground or shielding correctly.

Yes all pot casings connected to ground.

I did a complete rewire of my firebird last night and it’s as straightforward as you can get - one switch and one master volume. All components are stock and connected to ground. Super noisy. The wire was a combination of a two core shielded wire and vintage cloth covered wire. There are some long runs from switch to control cavity.

I’m thinking it must be the wire not being shielded - there’s no shielding in the cavities themselves and i know the fb wasn’t this noisy before i took all the old wire out (long gone now). 

mynameistrouble

Funkfingers said:

What resistance values were the Alpha pots that you removed and the ones that you installed? 

Stock were 500k replaced with 250k.

ICBM

mynameistrouble said:

Yes all pot casings connected to ground.

I did a complete rewire of my firebird last night and it’s as straightforward as you can get - one switch and one master volume. All components are stock and connected to ground. Super noisy. The wire was a combination of a two core shielded wire and vintage cloth covered wire. There are some long runs from switch to control cavity.

I’m thinking it must be the wire not being shielded - there’s no shielding in the cavities themselves and i know the fb wasn’t this noisy before i took all the old wire out (long gone now). 

There’s the problem.

You need one or the other. For a Firebird the long wiring run to the switch must be shielded cable, that will be extremely noisy if it’s not. You need to keep the exposed cores at the ends as short as possible too, unless the cavities are also shielded.

mynameistrouble

ICBM said:

mynameistrouble said:

Yes all pot casings connected to ground.

I did a complete rewire of my firebird last night and it’s as straightforward as you can get - one switch and one master volume. All components are stock and connected to ground. Super noisy. The wire was a combination of a two core shielded wire and vintage cloth covered wire. There are some long runs from switch to control cavity.

I’m thinking it must be the wire not being shielded - there’s no shielding in the cavities themselves and i know the fb wasn’t this noisy before i took all the old wire out (long gone now). 

There’s the problem.

You need one or the other. For a Firebird the long wiring run to the switch must be shielded cable, that will be extremely noisy if it’s not. You need to keep the exposed cores at the ends as short as possible too, unless the cavities are also shielded.

Can you recommend some shielded wire that would be up to the task?

Also, the bridge pickup braid wire is too short to reach the switch and needs an extension- what’s the best way to mitigate against the inevitable bit of exposed wire where the extension meets the pup wire?

ICBM

I use vintage-style braided shielded wire, or foil-shielded 4-conductor pickup cable to the switch (ground both the bare wire and the 4th core you’re not using).

If you need to extend a pickup cable you can use braided cable - push back the braiding a long way, join and heatshrink the cores, then pull the braiding forward to cover it and solder it together - if it doesn’t quite meet you can wind a bit of plain wire over the gap, a small one won’t matter.

By the way, I should mention that the word ‘pup’ (other than referring to a young dog) irritates me so much that I usually don’t read threads where it’s used... 

mynameistrouble

Thanks very much for your help - it’s great that I’m able to get such clear advice here.

Noted re ‘pups’ - pure laziness on my part due to writing on my phone. I will not repeat that mistake and risk you not helping in future!

ICBM

mynameistrouble said:

Thanks very much for your help - it’s great that I’m able to get such clear advice here.

Noted re ‘pups’ - pure laziness on my part due to writing on my phone. I will not repeat that mistake and risk you not helping in future!

lol

I don't know why it annoys me so much, it just does for some reason . It's as bad as 'axe' or 'plays like butter'...