Speaker Crackle

[axro]

I have a pair of powered computer speakers. The kind that just plug into the the headphone jack. I opened it up and the IC is a tda28222m.

The problem with is, you have very carefully move the volume knob(dual pot) to the right location of either 1 speaker will cut out or the other one will and it's really crackly. But If you can get it in the right spot both speakers work.

What would be the most logical cause of this?

 

[Nigel Goodwin]

Most probably just the volume control faulty, try cleaning it - WD40 is as good as anything, and better than most.

 

[cr0sh]

Not sure about WD-40

Personally, I keep that stuff far away from my electronics.

I would actually pick up a can of tuner/contact cleaner at an electronics shop; its made precisely for that kind of stuff - something like this:

**broken link removed**

 

[Dx3]

Yes. That's the answer. You have dirty pots. Clean them. If that doesn't clear it up, you have to buy a new dual pot. This problem is so common that I expect you've seen it before, but didn't think about it until you started thinking in terms of electronic design.

 

[Speakerguy]

Dirty potentiometer. Make sure there is no input signal, and then rotate the pot back and forth all the way many many times. This will scrape off dust, oxidation, whatever. After 50-100 times it should be mostly if not all crackle free.

I actually tricked a friend with this one time. He had some PC speakers with a real cheap, small inline volume control on one of the wires. I told him to stand back and "watch the magic". I grasped the volume control in my hand, and rotated the knob back and forth real quick in a such a way that he couldn't see. After 30 seconds and some "alakazam" ********, I handed it back to him and said "all done". When he rotated the volume knob and there was no crackle, he looked at me and said "You son of a *****!". I really got him good with that, never told him how I did it.

 

[axro]

How would rubbing alcohol work?

Nigel, have you ever used WD-40 on a pot. I've read on the net that WD40 and electrical contacts don't play well together.

 

[transistor495]

That's a phenomena I used to get irritated with vol pots

We'll get good sealed pots for higher prices. Low cost pots often make this crackling after a while when dirts getting in or poor contacts.

Anyway you should be proud of being an owner of a tda2822 desktop speaker system

Dirty potentiometer. Make sure there is no input signal, and then rotate the pot back and forth all the way many many times. This will scrape off dust, oxidation, whatever. After 50-100 times it should be mostly if not all crackle free.

I actually tricked a friend with this one time. He had some PC speakers with a real cheap, small inline volume control on one of the wires. I told him to stand back and "watch the magic". I grasped the volume control in my hand, and rotated the knob back and forth real quick in a such a way that he couldn't see. After 30 seconds and some "alakazam" ********, I handed it back to him and said "all done". When he rotated the volume knob and there was no crackle, he looked at me and said "You son of a *****!". I really got him good with that, never told him how I did it.

Looks like a different idea . I'm not much sure about that though..will try it out.

 

[transistor495]

Dirty potentiometer. Make sure there is no input signal, and then rotate the pot back and forth all the way many many times. This will scrape off dust, oxidation, whatever. After 50-100 times it should be mostly if not all crackle free.

It worked well on the 'inline' volume pot of my headphone. Thank you
I havent used it for many months so recently it was getting lots of crackling because of dust entered.
I might have done it(back and forth method) minimum 50times.