Cheapie 2.1 Speaker Set with static in left speaker

[Peale]

While dumpster diving I found a 2.1 speaker set. Static in the left
speaker.

I swapped speakers, problem persisted. I swapped the op amp out with a
known good one, same thing.

I'm new to this kind of thing, so I'm a bit perplexed as what to try next.
It's not the source, I've tried several different sources. Wiring appears
to be okay. Sound to the subwoofer and the right speaker is okay.

 

[Malissa Baldwin]

While dumpster diving I found a 2.1 speaker set. Static in the left
speaker.

I swapped speakers, problem persisted. I swapped the op amp out with a
known good one, same thing.

I'm new to this kind of thing, so I'm a bit perplexed as what to try next.
It's not the source, I've tried several different sources. Wiring appears
to be okay. Sound to the subwoofer and the right speaker is okay.

--http://www.pealefamily.net

I googled your problem and I got 40,020,203,029,209,102,683,204,603
hits and they all say that you get what you pay for.
But if you want to buy a new speaker system just google your problem
yourself and click on one of the 50,000,000 advertisments on the top.

 

[Dave]

While dumpster diving I found a 2.1 speaker set. Static in the left
speaker.

I swapped speakers, problem persisted. I swapped the op amp out with a
known good one, same thing.

I'm new to this kind of thing, so I'm a bit perplexed as what to try next.
It's not the source, I've tried several different sources. Wiring appears
to be okay. Sound to the subwoofer and the right speaker is okay.

Look at the mixer IC. It generally does tone control/balance/volume. Cost
about $4 to replace. If there are any discrete transistors, and I doubt
there are, try tapping them with something non-metallic and see if it
affects the sound. Otherwise, throw it away, ain't worth your time.

 

[Peale]

I googled your problem and I got 40,020,203,029,209,102,683,204,603
hits and they all say that you get what you pay for.
But if you want to buy a new speaker system just google your problem
yourself and click on one of the 50,000,000 advertisments on the top.

Well, "duh." But what fun is that?

 

[Peale]

Look at the mixer IC. It generally does tone control/balance/volume.
Cost about $4 to replace. If there are any discrete transistors, and
I doubt there are, try tapping them with something non-metallic and
see if it affects the sound. Otherwise, throw it away, ain't worth
your time.

It's a back-burner project, just something I've been tinkering around
with in my spare time. I'll check the mixer IC tonight.

 

[[email protected]]

While dumpster diving I found a 2.1 speaker set. Static in the left
speaker.

I swapped speakers, problem persisted.

in which speaker?

I swapped the op amp out with a
known good one, same thing.

I'm new to this kind of thing, so I'm a bit perplexed as what to try next.
It's not the source, I've tried several different sources. Wiring appears
to be okay. Sound to the subwoofer and the right speaker is okay.

--http://www.pealefamily.net

Just short the audio out at the various points in the signal chain
(dont short power amp output tho). When shorting before a stage made
no difference & shorting after it killed crackling, you know where its
coming from. Prodding with a bit of plastic also helps locate if its a
dry joint.


NT

 

[Peale]

[email protected] wrote in

in which speaker?

LOL...in the left speaker. If the problem traveled, I'd have found my
problem. ;-)

Just short the audio out at the various points in the signal chain
(dont short power amp output tho). When shorting before a stage made
no difference & shorting after it killed crackling, you know where its
coming from. Prodding with a bit of plastic also helps locate if its a
dry joint.

I touched up every joint I could, esp. the connectors on the PCB.

What do you mean, short the points? Take a wire and jump the signal
closer along in the chain to the output?

 

[Dave]

[email protected] wrote in


LOL...in the left speaker. If the problem traveled, I'd have found my
problem. ;-)


I touched up every joint I could, esp. the connectors on the PCB.

What do you mean, short the points? Take a wire and jump the signal
closer along in the chain to the output?

No, jump the signal to ground. You're effectively killing the audio signal
input from that point on. If the crackling persists, that means it's being
introduced downstream of the point you've shorted. Just keep moving
downstream along the signal path until the crackling goes away. The
component just upstream of your jumper point is the likely culprit.

 

[Arfa Daily]

No, jump the signal to ground. You're effectively killing the audio
signal input from that point on. If the crackling persists, that means
it's being introduced downstream of the point you've shorted. Just keep
moving downstream along the signal path until the crackling goes away.
The component just upstream of your jumper point is the likely culprit.

That is the preferred way of pinning down a problem like this, and is often
more effective than using a 'scope to try to distinguish between the crackly
noise, and the inherent stage noise. I would, however, warn agains employing
a direct shorting wire to do the job, unless you have schematics for an amp
to know exactly the 'safe' points to apply a direct ground connection to.
There are places that you certainly don't want to short directly to ground,
if you want the components to keep their magic smoke locked in. I would
recommend that you use a 47uF 35v capacitor, negative leg to ground, as your
'shorting wire'. The actual value isn't critical - whatever comes to hand.

Arfa