Operation: Make My Sparrow Rat Rod Gooder.

[muttley]

[mention]WhiskeyJack[/mention]

Take a look at this.
https://www.fralinpickups.com/2017/03/ ... -pots-101/

Its pretty clear and will save me and gerg a bit of typing. If you get hung up on any of it just ask.


On the cap thing. All a cap does is filter high frequencies out of the signal and pass them to ground. All the grounds need to be hooked up together at some point so thats why you see a ton of connections made to the casings and then also to all metal parts of the guitar. Ideally there is a ground "loop" so that the signal isnt compromised. Thats to help with shielding and induction so a pay grade above where you are now.

Essentially all a pickup output is is a hot signal and a ground signal. One end of the coil is ground and always ends up on that loop. The hot signal goes thru the pots and caps which change its strength and tonal shape by sending a quantity of that signal to ground.

Think a bout a sink full of water with an over flow pipe. The higher the over flow pipe the more water the sink holds. Move the overflow pipe lower and the water level is reduced. The water lost down that overflow pipe goes to the same place. Ground....

[Greg_L]

Read this:
https://randomnerdtutorials.com/electro ... ter-works/

Basically, your pickup induces a voltage, it's sent to the outer terminal of the volume pot, through the wiper, and out the middle terminal. From there it goes to the switch, and then on to the output jack, and out to the amp.

With "50s wiring" some of the HF signal from the volume wiper is being shunted to ground through the tone cap and pot...if you use it. The wiper is grounded on the tone pot so the tone pot acts as a variable resistor.

What you currently have is some ass backwards weirdo wiring. Gut it and start from scratch. It doesn't need to be that messy and complicated.

[Greg_L]

Yeah, read Mutt's link. That's good.

[muttley]

On your diagram, the yellow/white would be the hot signal, the part that is going to be manipulated by the pots and eventually the amp via the tip of the output jack. It comes from the finish wire on the pickup. The other wire from the pickup is the ground and comes from the start wire on the pickup. It always goes to ground and eventually ends up at the sleeve of the output jack.

Dont over think the schematic at this stage. You would be just as well off sticking to a standard schematic and wiring it up and take it from there. You learn just as much troubleshooting as researching. You dont need to know how to raise cattle to make a good burger..

[Greg_L]

It's weird that they have the pickup signal going into the wiper of the volume pots. Maybe that's some right handed pots on a left handed guitar shenanigans so the taper acts correctly while being spun in the opposite direction.

[muttley]

It's weird that they have the pickup signal going into the wiper of the volume pots. Maybe that's some right handed pots on a left handed guitar shenanigans so the taper acts correctly while being spun in the opposite direction.

To my mind that pot is gonna work backwards unless the pickup output has been reversed start and finish wires reveresed. Even then you are going to get phase issues. I havent really looked at it closely though. Like I said I think WJ would be best to strip it and redo it following a standard schematic. Then having practiced on breaker parts, get some decent CTS pots and a O drop and do it again...

[Greg_L]

Totally. Gut it down to nothing and start over.

[WhiskeyJack]

thanks dudes. I will read through both links tonight. I skimmed Mutts and it looked like it might be the roestta stone i am looking for.

to my knowledge this should all be "regularly" wired to work for any right handed normal guy to play it. All the knobs turn the right way. I may be wrong. I don't ever use the tone knobs really. But after a bit of monkeying around on other guitars neck pick ups and tone knobs i see myself getting more comfortable in that world.

I am going to gut it and hopefully clean it up and simplify it. I am also going to reread the Kent Armstrong wiring specs and see if maybe this weird jumble is not something their pick ups may require. Mutt sent them to me a while ago i just have to find the bookmark.

gutting tonight and making an order of parts as well. thanks guys!!!

[muttley]

........
I am going to gut it and hopefully clean it up and simplify it. I am also going to reread the Kent Armstrong wiring specs and see if maybe this weird jumble is not something their pick ups may require. Mutt sent them to me a while ago i just have to find the bookmark.
..........

No it isnt that. A pickup is a pickup. Physics is physics..

[Greg_L]

Here I made a little diagram for you. This is a basic Les Paul style cavity wiring.

s-l1600.jpg

BV3 and NV3 are bent back and soldered to the pot case.
NV2 connects to the neck pickup side of the selector switch
BV2 connects to the bridge pickup side of the selector switch
NV1 connects to the hot lead of the neck pickup
BV1 connects to the hot lead of the bridge pickup
The pickups' braided shielding or ground wire can ground at any convenient pot case.
The center of the pickup switch will go to the tip of the output jack.
The output jack sleeve can ground on any pot case.
The bridge/tailpiece wire will poke through the cavity somewhere. Solder it to any convenient pot case.

The grounding is important. See how that black wire loops around the pots in a horseshoe shape? That's what you want. You don't want a closed ground loop. Leave one end open. This way all the grounds travel the same path out of the guitar in the same direction. The horseshoe shape and single output jack ground ensures everything can only go one way out.

[WhiskeyJack]

Thanks Greg. that is also incredibly helpful.

parts ordered from stewmac. 1 to 4 weeks delivery to the fucking north pole.

I think though i will just practice some soldering chops on the stuff i took out of the cavity last night in the mean time. get an idea for how long it takes to do stuff to the back of the pot. Also maybe brush up on some desoldering as well. I should try and salvage those old green caps what ever they were.

How can i figure out what uf those green ones were? With a multimeter?

[Greg_L]

Thanks Greg. that is also incredibly helpful.

parts ordered from stewmac. 1 to 4 weeks delivery to the fucking north pole.

I think though i will just practice some soldering chops on the stuff i took out of the cavity last night in the mean time. get an idea for how long it takes to do stuff to the back of the pot. Also maybe brush up on some desoldering as well. I should try and salvage those old green caps what ever they were.

How can i figure out what uf those green ones were? With a multimeter?

Yeah take it apart and put it back together correctly with the old parts for practice.

The caps may have some markings on them. Tiny little numbers. Post em if you see them. A multimeter won't help unless it can measure capacitance.

[JD01]

[mention]WhiskeyJack[/mention] is there I guy you can go to locally to sort all of this out for you after you fuck it up?

[WhiskeyJack]

@WhiskeyJack is there I guy you can go to locally to sort all of this out for you after you fuck it up?

Yea i got him on speed dial. I can't make it worse than who ever did that last / original job.

[Greg_L]

Santa doesn't work this time of year.

[Greg_L]

[mention]WhiskeyJack[/mention] you can't screw this up. Not with mutt and me guiding you along. The worst you can do is a bad solder joint....and even that can be fine in something as insignificant as guitar wiring. Look at how sloppy it is already...and it works. Just do the basic hookups and you'll be fine.

[WhiskeyJack]

Exactly.

I am in good hands and i trust my own to do their thing. I am not too worried about it.

[muttley]

One thing I would point out is that soldering to the back of pots requires a lot more heat than soldering to the lugs. What Iron have you got? One of the biggest frustrations for noobs at this is either too much wattage or too little.

[WhiskeyJack]

One thing I would point out is that soldering to the back of pots requires a lot more heat than soldering to the lugs. What Iron have you got? One of the biggest frustrations for noobs at this is either too much wattage or too little.

Well to complicate my workspace / workflow i have two irons. I got the standard chain store special Weller pencil type 25W small electronics guy for doing the light duty stuff. Then for the lugs i figure i will use this:



Read more here: https://therecordingrebels.com/viewtopi ... ing#p65459

I only have a big wide chisel tip for the Ungar. My dad can't seem to find all his extra tips in all his boxes of stuff and i went looking for some replacements a few months ago and it's a tough search. they are out there but they are $$$ or i have to buy 500 dollars worth of an entire collection of tips i know i will never use.

I will likely just use both of them as much of a pain as that will be.

[Greg_L]

Well to complicate my workspace / workflow i have two irons. I got the standard chain store special Weller pencil type 25W small electronics guy for doing the light duty stuff. Then for the lugs i figure i will use this:



Read more here: https://therecordingrebels.com/viewtopi ... ing#p65459

I only have a big wide chisel tip for the Ungar. My dad can't seem to find all his extra tips in all his boxes of stuff and i went looking for some replacements a few months ago and it's a tough search. they are out there but they are $$$ or i have to buy 500 dollars worth of an entire collection of tips i know i will never use.

I will likely just use both of them as much of a pain as that will be.

That will definitely handle soldering to the back of a pot. No problem.

It helps sometimes to scuff the back of the pot a little and melt a little puddle of solder by itself before you try to stick things into it. Then you just heat the puddle, add the wire to the wet puddle, remove the heat while holding the wire in the puddle. The solder will cool quickly and the wire will be frozen in time inside of it.