Problem with a 100 k dual manual volume controller

[rajaram04]

Hello sir

I am using a 100k dual volume control as a volume controller for a volume pedal




It is working smoothly & on one side i am getting full output but on either side volume is not fully muting up the sound

a lil.bit output i am still getting & it is enough to make a mark

so how to sort out this problem ?

any special design or what ?

 

[BradtheRad]

Did you connect one terminal to ground? If so then you should be able to reduce the volume all the way down to silence.

If it won't do that, then there might be a break (or burned area?) on the resistive film inside the pot, exactly where the wiper arm reaches the end of its travel.

 

[rajaram04]

Did you connect one terminal to ground? If so then you should be able to reduce the volume all the way down to silence.

If it won't do that, then there might be a break (or burned area?) on the resistive film inside the pot, exactly where the wiper arm reaches the end of its travel.

ya i connect the earth terminal as per diagram exactly here

& replace so many times with a new unit but still have same problm :-(

 

[BradtheRad]

& replace so many times with a new unit but still have same problm :-(

Usually a potentiometer goes bad gradually. It gets 'scratchy'.

But if a new unit goes bad (and then another) it suggests there is too much current going through it.
Pots are only rated for 1/8 W, or thereabouts. At 9V, that is only 14 mA.

So when you dial it to either extreme, it can increase the current inside it, enough to cause burning. I have done this more than once. When smoke comes out of the unit, that is how I know when it happens.

So you must make certain whether there is sufficient safety resistance somewhere.

Have you opened up the units, to examine for damage inside?

 

[FvM]

As a first step, I would check the potentiometer with a multimeter.

 

[rajaram04]

Usually a potentiometer goes bad gradually. It gets 'scratchy'.

But if a new unit goes bad (and then another) it suggests there is too much current going through it.
Pots are only rated for 1/8 W, or thereabouts. At 9V, that is only 14 mA.

So when you dial it to either extreme, it can increase the current inside it, enough to cause burning. I have done this more than once. When smoke comes out of the unit, that is how I know when it happens.

So you must make certain whether there is sufficient safety resistance somewhere.

Have you opened up the units, to examine for damage inside?

sir unit is alright , when we connect it to PA system accessories like amplifiers mixer equilizers etc etc it works properly & not only this one , all our instruments work properly but when i connect this in between any amplifier & my musical instrument its not working fully i mean full volume is properly working but at zero point a lil.bit sound is still coming out & marking its presence