volume pot behaving like tone pot

[hammo123]

I'm having a baffling problem hopefully someone can shed some light onto.
I have assembled a tele thinline out of parts which includes 2 x Catswhiskers WRHB & the standard scratchplate/tone/vol pot configuration..so have wired it following the standard thinline diagram [attached]
Results are a lovely clean hum free & beautiful tone on all selections of the PUP switching but the volume pot rather than taper off the volume is acting similar to a tone pot..>:<
The tone pot seems to work normally.
I've checked & resoldered all my joints & checked continuity of connections & earth is ok & ..I'm quite proficient @ soldering ..having recently done another 5 guitars with no issues..
The Pots are standard CTS 500k audio taper & i used a Sprague .047mfd Orange Drop…
Any advice on where to go troubleshooting would be greatly appreciated & thanks in advance

 

[ItchyFingers]

A picture of the wiring diagram is not going to generally give people enough to work with in helping solving your problem. That particular diagram can be a bit confusing due to the identification pointers being the same colour and type as the actual wires.
A picture of your own actual wiring would be better to diagnose. A coloured diagram seems to make things easier as well.

 

[BryMelvin]

Yes please post a pic or pics it sounds like a wiring mistake, So we'd have to see it to find it.


"Darn it's hard to type while covered in cats."

yep even harder when they walk on the keyboard though...and if I get up they wlk on the power or sleep key.....

 

[sjtalon]

Do you have the outer volume pot terminal grounded (earth) ?

Reference your diagram, the vol. term on the right needs to be grounded.

Or the prob could be the pot got fried in the solder process.

 

[BryMelvin]

+1 ^ Thought of the same thing while I was washing dishes !!

 

[dsutton24]

Do you have the outer volume pot terminal grounded (earth) ?

Almost certainly the source of your trouble. It's easy to forget to ground that third lug. If you're building on a plastic pickguard, it's important to make sure you run ground jumpers to the switch frame and the tone pot otherwise you can have controls that growl as your hand gets near them.

 

[hammo123]

Thanks for all your replies guys..
Yes the outter terminal is definitely bent back & soldered to the body of the pot & grounded..
I'm inclined to think maybe I somehow fried the pot or it may have even been faulty to start with as I sure didn't overheat it whilst soldering ..
I will replace the Vol pot as I have a spare & take a pic when i pull the guitar apart to do this..hopefully this will remedy the issue
Cheers again & will report back the outcome

 

[rphunt2002]

Thanks for all your replies guys..
Yes the outter terminal is definitely bent back & soldered to the body of the pot & grounded..
I'm inclined to think maybe I somehow fried the pot or it may have even been faulty to start with as I sure didn't overheat it whilst soldering ..
I will replace the Vol pot as I have a spare & take a pic when i pull the guitar apart to do this..hopefully this will remedy the issue
Cheers again & will report back the outcome

When you have it open, first just disconnect the tone pot and cap, see if the vol still has the problem.

 

[Rob DiStefano]

some good things to keep in mind with regards to passive guitar circuits and pots ...

volume pots actually are "tone" pots. when wide open, they deliver the maximum amount of signal and treble to the jack. when dialed down even a bit, some amount of treble is shunted to the ground side of the pot. this leads to the "overcoat tone" that blankets the treble. strapping on a "bleeder" cap of perhaps .001uf value will guarantee that some amount of treble will always "bleed off" to the jack.

loaded tone pots are also always shunting some amount of treble to ground, even when totally "closed" (they're not). if the tone pot is a no-load, when it's turned off, it's totally out of the circuit.

 

[sjtalon]

if the tone pot is a no-load, when it's turned off, it's totally out of the circuit.

and our good buddy Rob LOVES no loads !!!!




I do have to make one of those one day and give it a whirl Rob. First though, I have had one pickup and two different sets of pups for over a couple months now to put in three geetars I have here...................man, not enough hours in the day !

 

[rphunt2002]

Results are a lovely clean hum free & beautiful tone on all selections of the PUP switching but the volume pot rather than taper off the volume is acting similar to a tone pot

That statement there suggests that the 3rd tab on the volume pot is not grounded, if indeed the volume does not go down to silent.

 

[sjtalon]

Yes the outter terminal is definitely bent back & soldered to the body of the pot & grounded..

Been there, done that

 

[rphunt2002]

Been there, done that

Yeah, I would check a little more. Maybe with a meter to, say, the output jack.

 

[hammo123]

Solved

Just following up on the issue i had..
I re-soldered & checked the connections to the said Pot & still no joy..
Replaced the pot & problem solved..
Thanks again for everyone's help & suggestions

 

[sjtalon]

Happy pickin'

 

[FabriceKaiser]

I'm currently experiencing the exact same problem. I'm about to go and prod under the hood as we speak. Thanks a lot to the whole of you for posting here. This is beyond helpful.

 

[FabriceKaiser]

Fixed!!! After checking out the wiring, I redid the solder joint between the cap, the volume pot leg and the pot casing. There was also a ground wire connecting the switch casing to the volume pot casing... No idea why. It very well could have been something I did while following a dodgy wiring diagram.
In any case, I removed it and the volume pot is now operating normally.
Thanks a lot, guys!