Volume pot not grounded? Advice please!

[arnoldsnarb49]

Hi all,

I've wired up the guitar and things are almost working right. I've attached a pic below. As it stands, the front position on the switch and the back position on the switch seem to be catching signal from both pickups together; the middle position captures no signal. I am guessing I need to wire the jumper connections on the switch more carefully.

My real question is this: I don't get a signal through the cable unless I touch the volume shaft (I have not put the knob on yet). I touch the volume shaft with my finger--everything seems great. I don't touch it, nothing. I assume something is not grounded correctly but this is my first time wiring anything and I have no idea what needs to be grounded that isn't.

Thanks for any help!

 

[Cagey]

Are you sure you're holding your mouth right?

Just kidding.

It sounds to me like you have a defective pot. Touching the shaft puts just enough pressure on the armature to mechanically/electrically allow the wiper to contact the internal resistor strip. When you're not touching it, the pot is open, so no signal gets through.

As an aside, soldering to pot bodies is poor practice. I know a lotta folks do it, but they're not designed for that kind of abuse. Especially not modern pots, which are built so cheaply its a wonder anybody is interested in even being in that business. OEMs get away with it by using higher-wattage soldering irons that allow them to get on and off the thing really fast without burning up the part. But, most folks don't have the sort of luxury that allows them to have more than one soldering iron running. You may want to consider using grounding lugs instead of terrorizing your pots. See this thread.

 

[arnoldsnarb49]

Thanks, Cagey! Just ordered them and some new pots.

I've gotten lots of compliments on the neck you set up and burnished for me.

 

[Cagey]

Great news on all points!

Now, tell all your friends to send me their necks before they're the last little rascals on Earth that don't have a properly treated neck!  :icon_biggrin:

 

[justinianus]

It seems to me like you didn't wire the back of your volume pot to the back of the other pot, I'd start by doing that to make a ground connection.

 

[fdesalvo]

I love ground busses.  I get crazy with these things.  Here are some pics from a couple of my past projects that illustrate how effective these are.  For people that love swapping pickups and other components, you need only heat the pot once to solder the buss.  Next time you swap pickups, resistors, or caps, you put a hemostat between the pot and component and solder away.

 

[arnoldsnarb49]

Thanks! I ended up getting a 5 way switch and new pots and rewiring the whole thing using ground lugs. Now everything works great! When I first tried it out after rewiring in the middle of the day today the volume pot wouldn't turn off and there was a lot of noise. I took a look and *voila* the pickup ground was loose. Soldered that down good and it all seems right as rain now.

I also managed to build a speaker cab while I sorted out all this wiring mayhem. The head is a Toad Suck Tones 70s Marshall rackmount clone with Bendix 6094 power tubes. It's crazy clean, so I grabbed an EP Booster and between the Seymour Duncans and the boost I can get some nice grit going now. The speaker is an alnico Tone Tubby Humboldt.

 

[fdesalvo]

Nice!  Check out the SL Drive - it's tasty if you only have a little space.