Wiring ideas

[ezas]

I got my new neck PU from GFS and I'm redoing the wiring and I could use some ideas. The pickups use two conductor wires and I'm looking for alternatives to running all the grounds to the back of the switch. It's 2 hums, a 3-way switch and a single volume and single tone controls. I'm using the wiring here: http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=2h_1v_1t_3w

I have these things that need to go to ground
The back off the pots
The bridge wire
Neck hum ground
Bridge hum grounds

Last time I did this I ran everything to the back of the switch and it worked but it was a lot of things to solder to the one lug on the back of the 3-way switch.

Being a semi-solid I need to keep an eye on not having wires cross the opening. I have plenty of length of PU lead to work with. I was thinking to run the PU wires over the volume control soldering the braid to the back of the volume pot and then the hot to the switch but that pretty much runs the wires right across the f-hole.

So just looking for some ideas on ways to do a neat job on the wiring. Pictures below:

 

[Jumble Jumble]

How about a piece of stripboard.

http://www.digikey.com/product-detail/en/8022/V2018-ND/565947?WT.mc_id=PLA_565947

Each piece of wire goes in one hole on the same strip, or join a few strips and make a grid where every hole is ground.

 

[ezas]

Not sure how I would make that work in a semi-solid. It would be one more thing to stuff in the F-hole and try to keep out of sight.

While searching for information on 12a/b switchcraft jacks, I came across this idea to cut down on the number of wires to connect to the switch. But then you would have to undo it to  remove one pickup.

 

[Jumble Jumble]

The stripboard is tiny. You could stick it to the back of a pot with a sticky pad, or direct to the wood next to a pot. Seriously, these holes are 0.1" apart:

So if you did three rows of four contacts, giving you nine ground points, you're looking at a piece of stripboard just over 0.3" x 0.4" in size. About the size of the back of a DPDT mini toggle, except flat.

 

[ezas]

Interesting . . . and the wires just poke in the holes or they get soldered in or what?

But I don't see how that would help me with the braid.

 

[Jumble Jumble]

You poke them through on the blank side, then turn it over and solder them on the metallic side.

I see what you mean about the braid, it wouldn't fit through the holes. I think the way I would deal with that is to twist them together with a thin black solid-core wire, solder and tape that join, and then take that to the stripboard. However, if you do that, then the stripboard isn't really helping you very much, as you've already converted your two big braids into one thin wire, which could go anywhere really.

 

[ezas]

I think  i'm going to solder the braids to the volume pot and then run the black wires to the switch. Then I'll just run one wire to the ground lug of the switch and the bridge wire to the tone pot. Then just try to do that in a way that won't show through the F-hole.

 

[Jumble Jumble]

The other thing is, the way people talk, you'd think the pots were being destroyed at the rate of dozens a day by people soldering wires to the backs of them. I've never had one go and when I first started wiring I would hold a 25W soldering iron to the pot for absolutely ages. I think you probably have to be really abusing a pot before you damage it. In this situation I might well just use the pots a ground points for simplicity's sake.

 

[ezas]

I agree that the risk of damages to pots is overblown. I learned to solder doing wiring harnesses and i've yet to smoke a pot, at least in any way I could tell. I've been tempted to ask here 'how do you tell if you burned up a pot' since as near as I can tell i've yet to do it.

 

[Super Turbo Deluxe Custom]

Overblown or not, I don't do it because I can't get anything to stick to it.  It's kind of been accepted because it's done.  In non guitar wiring applications, it's seldom done. 

 

[Jumble Jumble]

Clean the back off the pot off with a wire brush or sandpaper if you're having adhesion problems.

Not steel wool, bits of that get everywhere.

 

[Cagey]

I agree that the risk of damages to pots is overblown. I learned to solder doing wiring harnesses and i've yet to smoke a pot, at least in any way I could tell. I've been tempted to ask here 'how do you tell if you burned up a pot' since as near as I can tell i've yet to do it.

A lot of risky behavior isn't immediately detrimental or fatal, if ever. Things like driving, boxing, skydiving... for instance, It's common knowledge that smoking increases the risk of certain kinds of cancer and pulmonary disease. In fact, it's so likely that millions of dollars are spent annually educating people about it and trying to get the addicts to quit. Yet, here I am after 40 years of smoking with no cancer. Buddy of mine has 45 years on the sticks, and his mother's got 60+. So, is it ok to smoke? Of course not.

The pots used in guitars are designed to dissipate 2 watts, tops. Some are smaller. The internal resistive element is made of carbon-impregnated plastic, which is exposed to a copper alloy wiper that slides along the element to tap it and provide a variable electrical resistance. If you get it any hotter than it's designed to be, it can warp or deteriorate, develop oxidation, in the extreme it may even open up and break the circuit. So, what do you suppose happens when you put a 40 watt soldering iron against the housing? Depending on how long the iron is on there you can have one or more of several effects from none to shortened life expectancy to reduced performance to complete destruction.

Now, it's true that guitar pots have had leads soldered to their housings for many, many moons. I'm sure there are other pieces of poorly constructed gear out there where they've committed the same sin. But, what's interesting is in guitars is they're using 2 watt pots when the circuit is never going to see voltages or currents that would produce anything more than milliwatts of power. So, why do they fail? They're grossly over-spec'd. They should last forever. The only reason they use 2 watt parts is because A) they're common as dirt and so are inexpensive, and B) because they're mechanically robust.

Metaphorically speaking, they fail because they're abused at birth. Fender, Gibson, PRS, Suhr, et al drop them on their heads right at the factory.

Power dissipation is a funny thing, though. Ratings are often understood and treated as instantaneous, but in reality there is a time component to it. A part rated at 1 watt may be able to dissipate 10 watts if the duration is short enough. So, with the solder-to-the-body trick, what manufacturers do is use a very hot iron, perhaps 60 watts or better. That allows them to heat the part up to soldering temperatures very quickly, do the deed, and get off the thing before much, if any damage is done.

Hobbyists and DIY types usually don't maintain a stable of soldering irons to match each application. They have one, and it's a compromise value that lets them do the most with a single tool. That usually means 25 to 40 watts. But, you put an iron that small on a pot body, and the iron will immediately begin to cool off due to the heat sinking effect of the housing. After some time, it'll heat back up to soldering temperature, but so will the hapless pot's internals. Boom, you've injured your part.

So, I don't do it. You can if you want, but don't come crying to me when a pot that should last 1000 years fails in 3 months.

 

[Jumble Jumble]

A lot of risky behavior isn't immediately detrimental or fatal, if ever. Things like driving, boxing, skydiving... for instance, It's common knowledge that smoking increases the risk of certain kinds of cancer and pulmonary disease. In fact, it's so likely that millions of dollars are spent annually educating people about it and trying to get the addicts to quit. Yet, here I am after 40 years of smoking with no cancer. Buddy of mine has 45 years on the sticks, and his mother's got 60+. So, is it ok to smoke? Of course not.

The difference there being, the thing your risking is your life, not a $2 pot. Also Skydiving is way safer than driving or boxing!

So, why do they fail? They're grossly over-spec'd. They should last forever. The only reason they use 2 watt parts is because A) they're common as dirt and so are inexpensive, and B) because they're mechanically robust.

I've never actually had one fail, although I'd say none of my guitars have pots in them that are older than about 10 years.

So, I don't do it. You can if you want, but don't come crying to me when a pot that should last 1000 years fails in 3 months.

No way?! Really, people's pots are going wrong three months after they worked on them? I dunno, maybe they're holding the soldering iron on for like, an hour, but that seems absolutely whack to me. If that's true then fair enough, avoid it.

The only part of a guitar wiring that's actually properly failed me is the solder connection from wire to jack that was part of a stock USA Strat. This was before I knew what I was doing, so I used sticky tape to connect everything back up, and then it stayed like that for 5 years or so until I started modding. You had to hold the cable at a certain angle to keep the wire connected, but fortunately tucking it through the strap achieved that.

 

[Cagey]

Well, we're not talking absolutes, here. I would venture to guess that most people have never had one fail. But, why risk it for a $.10 cent part? Using ground lugs is not only cheap insurance, they're a lot easier to solder to.

 

[Jumble Jumble]

Definitely agreed on that last part. I do avoid it whenever possible, purely because pretty much anything else is easy to solder to.

ccasion14:

 

[ezas]

I solder my pots by holding a 40w iron to the back of the pot for 5 seconds than position the wire and quick zap with solder, and second or two more holding the iron before pulling away. I've never had a problem getting the solder/connection to stick and I've yet to rough up the surface of the back of the pot. I have not done a lot of connections to pots. Probably 15-20 or so on CTS, Alpha and few no-brand pots that came on import guitars. I do keep the tip of my iron seriously clean though so I don't know how much that is helping me. I don't always get as shiny a solder joint as I would like however.

I had one case where I fumbled with picking up something in my left hand to press the wire down (actually a ring terminal) and probably had the iron on the back of the pot via the ring terminal for at least 10 seconds, and maybe as long as 15 and that pot is working fine as far as I can tell.

Before guitar wiring I had only made a few wire to wire solder joints so i'm pretty much learning to solder by doing guitars. So far all my harnesses have worked first time (probably shouldn't have said that out loud, this next one is sure to fail now).

Where I do wish I could do better is getting a nice 'pad' of solder on the back of the pot instead of the solder flowing out in to a thin(ish) layer of solder. Any tips on how to do that?