Further wiring woes and a request for advice

Kalimna

A quick update. I re-soldered the switch last night, and heatshrink-wrapped the joins. Seemed to work, but then put it all back into the (in hindsight, too small) cavity and was getting a simillar almost on-off volume and tone that was working but not too much.
And then there was an intermittent complete loss of output - suggestive of a problem on the switch with either the solder joints or the switch itself.

So. Back with the 'iron tonight and a fresh switch. I am tempted to re-wire the whole thing but as that's a fair old job (and I don;t have any spare A500k pots right now) I will start with just the switch and try to enlarge the cavity as much as I can - there is maybe 2-3mm of extra width and 3-4 extra length available.
I was also thinking of replacing the braided cable with some 4-conductor pickup wire I have lying around, but again that would be for another day.

It had occurred to me that maybe the pots had been damaged by excess heat from soldering - is there an easy way to check that?

Lastly, is 15nF a little on the small side for neck/mid pickups?

Cheers for all comments/advice so far.

Adam

Funkfingers

Dave_Mc said:. 

if I have new pickups which I'm dying to hear, I'll sometimes do an easier job so I can hear them sooner- so I might not bother swapping pots or something like that, even though eventually I might mean to.

I learned the hard way that this is not always a good idea.

e.g. I have a favourite eccentric trio of Seymour Duncan pickups that I try to keep together. These sounded great in a cheap Sterling SUB Silo HSS guitar via CTS A250k pots.

More recently, I tested the same pickups in an old Charvel Model 3 via its stock A500k pots. Their signal strength was fine but their tone was horribly thinned out. 

The Charvel guitar now sports DiMarzio pickups.

ICBM

Kalimna said:

A quick update. I re-soldered the switch last night, and heatshrink-wrapped the joins. Seemed to work, but then put it all back into the (in hindsight, too small) cavity and was getting a simillar almost on-off volume and tone that was working but not too much.
And then there was an intermittent complete loss of output - suggestive of a problem on the switch with either the solder joints or the switch itself.

Sounds to me like you've still got some sort of short, and still probably downstream of the volume pot. It could even be inside one of the braided cables, if they're bent at a sharp enough angle - the weave of the cloth can separate enough for the core to touch the shield.

Kalimna

ICBM said:

Kalimna said:

A quick update. I re-soldered the switch last night, and heatshrink-wrapped the joins. Seemed to work, but then put it all back into the (in hindsight, too small) cavity and was getting a simillar almost on-off volume and tone that was working but not too much.
And then there was an intermittent complete loss of output - suggestive of a problem on the switch with either the solder joints or the switch itself.

Sounds to me like you've still got some sort of short, and still probably downstream of the volume pot. It could even be inside one of the braided cables, if they're bent at a sharp enough angle - the weave of the cloth can separate enough for the core to touch the shield.

Would you recommend replacing the braided wire with unshielded multi-core? or perhaps just the portion within the switch cavity? If that makes sense, as it's fairly unlikely that there is a spike of braid poking through one of the straight-ish lengths.

And forgive my naive question, but when you say 'downstream of the vol pot', do you mean between the vol pot and output jack, or between the pot and the rest of the electrics?

Cheers,
Adam

ICBM

Kalimna said:

Would you recommend replacing the braided wire with unshielded multi-core? or perhaps just the portion within the switch cavity? If that makes sense, as it's fairly unlikely that there is a spike of braid poking through one of the straight-ish lengths.

Not unshielded unless the cavities are shielded, and you don't think they are.

If possible I would try to determine at exactly what point of stuffing the wiring back into the cavities the problem occurs, which should help in identifying where it is. I appreciate this may be tricky, but I always prefer to try to identify the actual cause of a problem rather than just guessing and changing stuff.

Kalimna said:

And forgive my naive question, but when you say 'downstream of the vol pot', do you mean between the vol pot and output jack, or between the pot and the rest of the electrics?

The first. Signal flow is from the pickups to the amp, thus 'downstream of' something is between the component and the amp.

Kalimna

ICBM said:

Kalimna said:

Would you recommend replacing the braided wire with unshielded multi-core? or perhaps just the portion within the switch cavity? If that makes sense, as it's fairly unlikely that there is a spike of braid poking through one of the straight-ish lengths.

Not unshielded unless the cavities are shielded, and you don't think they are.

If possible I would try to determine at exactly what point of stuffing the wiring back into the cavities the problem occurs, which should help in identifying where it is. I appreciate this may be tricky, but I always prefer to try to identify the actual cause of a problem rather than just guessing and changing stuff.

Kalimna said:

And forgive my naive question, but when you say 'downstream of the vol pot', do you mean between the vol pot and output jack, or between the pot and the rest of the electrics?

The first. Signal flow is from the pickups to the amp, thus 'downstream of' something is between the component and the amp.

Thank you - that is pretty much what I thought, but confirmation is always nice
Cheers - time to get the 'iron and DMM out when I get home!

Dave_Mc

Funkfingers said:

Dave_Mc said:. 

if I have new pickups which I'm dying to hear, I'll sometimes do an easier job so I can hear them sooner- so I might not bother swapping pots or something like that, even though eventually I might mean to.

I learned the hard way that this is not always a good idea.

e.g. I have a favourite eccentric trio of Seymour Duncan pickups that I try to keep together. These sounded great in a cheap Sterling SUB Silo HSS guitar via CTS A250k pots.

More recently, I tested the same pickups in an old Charvel Model 3 via its stock A500k pots. Their signal strength was fine but their tone was horribly thinned out. 

The Charvel guitar now sports DiMarzio pickups.

Oh yeah definitely. I meant more subtle swaps than that- if the guitar had a stock linear pot (I prefer log) I might not bother swapping that until later. Or if I had a replacement higher quality pot on hand, but there wasn't really anything wrong with the original pot. That kind of thing. Definitely if you want to hear the pickups "right", having the correct value of pots is very important!

ICBM said:

Kalimna said:

A quick update. I re-soldered the switch last night, and heatshrink-wrapped the joins. Seemed to work, but then put it all back into the (in hindsight, too small) cavity and was getting a simillar almost on-off volume and tone that was working but not too much.
And then there was an intermittent complete loss of output - suggestive of a problem on the switch with either the solder joints or the switch itself.

Sounds to me like you've still got some sort of short, and still probably downstream of the volume pot. It could even be inside one of the braided cables, if they're bent at a sharp enough angle - the weave of the cloth can separate enough for the core to touch the shield.

Yeah definitely. Too small a cavity and braided cables are kind of a recipe for something shorting out.

Actually braided cables (or even the bare wire from a 4-conductor humbucker) plus me are a recipe for shorting out, but that's a whole other problem!

EDIT: Agreed about trying to work out where the problem is- if I have a guitar where I suspect unwanted grounding/shorting is going to happen*, I leave the multimeter connected (and turned on) to a short instrument cable plugged into the guitar jack socket and keep an eye on the screen as I'm refitting the cavity cover and screwing in the screws. If the reading goes wrong you pretty much know that's the point where something is touching and you can often work out what the problem is based on which screw you were screwing in when you lost the reading...

* that's basically every single guitar, then.