Help with a simple pot project

[TheGingerOne]

Hello all. I am pretty new to all of this, so I am staring out with what seems liek a very basic project. A devise which will take an input from a guitar (1/4 inch input), and be able to control the volume level with a potentiometer and output the signal to an amp (also 1/4 inch). I am following this very basic diagram whcih I found online.

**broken link removed**

I am running into some problems, and it is kind of frustrating because it looks so simple. Maybe some of you can help me. The diagram does not specify which ends of the input/output are positive/ negative. Does this matter? Also, should the circuit be grounded anyplace? Also, could it not be working because I bought the wrong stuff from RadioShack? Any help is appreciated. Thanks.

 

[BeeBop]

Hello all. I am pretty new to all of this, so I am staring out with what seems liek a very basic project. A devise which will take an input from a guitar (1/4 inch input), and be able to control the volume level with a potentiometer and output the signal to an amp (also 1/4 inch). I am following this very basic diagram whcih I found online.


I am running into some problems, and it is kind of frustrating because it looks so simple. Maybe some of you can help me. The diagram does not specify which ends of the input/output are positive/ negative. Does this matter? Also, should the circuit be grounded anyplace? Also, could it not be working because I bought the wrong stuff from RadioShack? Any help is appreciated. Thanks.

Hi Ginger,

The wire which loops over the top of your diagram, and which goes to pin 1 of the pot is the ground. The outside rings of the jacks are connected from in to pin 1 to the outside ring of out. This connection is made with the shield of the cable. The inverted pyramids of lines are ground symbols.
The wire on the inside of the cable is connected to the prong part of the jacks, and goes from the input to pin 3 on the pot. Pin 2 of the pot is connected to the inside wire of your shielded cable to the prong part of your output jack. (Hope this makes sense to you.)

 

[Chippie]

Hopefully you will understand the sketch I've attached...

 

[TheGingerOne]

Thank you for all your feedback.

BeeBop, I tried my best to do what you were saying. What do you mean by "this connection is made with the shield of the cable?"

Heres a picture of what i tried.

**broken link removed**

Input on the left. Output on the right.

When i tried this, i did get some sound through to my amp, but only when i would hold both ends of the inputs. Also, the volume did not seem to be increasing/decreasing when i moved the switch on the pot. Any idea of what i could be doing wrong?

 

[birdman0_o]

Just a quick suggestion, linear will work fine, however normally a logarithmic pot is used for sound because our ears work logarithmically.

 

[Boncuk]

a 1MΩ pot is way too high to control volume.

Better use 10KΩ to 47KΩ.

Replace the single wires with shielded cable connecting the shielding as on the photo, (right hand pin of the pot) and remove only as much insulation of the cable as necessary to get to the pins.

Boncuk