my amp left channel still have some sound from the source i.e. CD player even the volume control is turned down all the way.
when i turn the volume up, everything looks like normal and balance between left and right speaker.
I am suspecting the fault is coming from the volume control variable resistor.
1. Could the fault coming from other components?
2. If I don't fix it, would it lead to more serious issue latter?
Thanks.
when i turn the volume up, everything looks like normal and balance between left and right speaker.
I am suspecting the fault is coming from the volume control variable resistor.
1. Could the fault coming from other components?
2. If I don't fix it, would it lead to more serious issue latter?
Thanks.
Normally with the pot in the fully off position the wiper is shorted to ground, so it is most likely the pot, as with a dead short on the wiper no sound should get through. test with the multimeter each channel from middle pin to outer pins. both should be pretty close, with one side measuring as close to zero ohms as your meter will read, and the other side measuring the nominal value of the pot (eg 20K or whatever the pot is rated at).
Finding a good pot that tracks the same for both channels at the low volume settings is difficult. I ended up getting a cheap stepped attenuator for about $10 from Ebay (HK seller).
Tony.
Finding a good pot that tracks the same for both channels at the low volume settings is difficult. I ended up getting a cheap stepped attenuator for about $10 from Ebay (HK seller).
Tony.
Spray contact cleaner into the pot and turn it vigorously a few times. If ( carbon?) dust is the problem it will clear up . If not the pot is probably defective. You might have to replace it. But try cleaning it several times before deciding to replace it.
The problem is most likely the grounding of the pot. In order to turn completely off, both wiper and the grounded end (minimum vol. end) should be at zero potential with respect to signal ground. With the power off, test with an ohmmeter as Wintermute suggests. Also check that the overall resistance from one end to the other (the outer pins) is similar in value for both channels. If the fault is other than grounding, this will not be similar. i.e within say 5%.
Initially, I would resolder the pin connections under the PCB and retry. If you notice variable volume levels or scratchiness at minimum volume , I'd look at cleaning the pot then, assuming it can be cleaned, as some recent types can't.
Re damage: I don't think the problem will be catastrophic if not repaired. The worst that can happen is that the amplifier will swing to higher volume at lower settings but probably still controllable such that you can prevent speaker damage. I doubt you'll put up with it for long in that state, though.
Initially, I would resolder the pin connections under the PCB and retry. If you notice variable volume levels or scratchiness at minimum volume , I'd look at cleaning the pot then, assuming it can be cleaned, as some recent types can't.
Re damage: I don't think the problem will be catastrophic if not repaired. The worst that can happen is that the amplifier will swing to higher volume at lower settings but probably still controllable such that you can prevent speaker damage. I doubt you'll put up with it for long in that state, though.
wintermute, ashok, your suggestions fixed the issue.
One of the pot don't give me complete zero ohm when turn to either end where as the other one shows zero ohm. I don't have contact cleaner but i pour IPA over the pot and turn it a few times. Measuring the pot again, walla!!! is zero ohm for both end.
Powering it on, not only did the volume off was fixed, the obvious lower left volume that is lower than right is also fixed.
thanks a a lot guys.
One of the pot don't give me complete zero ohm when turn to either end where as the other one shows zero ohm. I don't have contact cleaner but i pour IPA over the pot and turn it a few times. Measuring the pot again, walla!!! is zero ohm for both end.
Powering it on, not only did the volume off was fixed, the obvious lower left volume that is lower than right is also fixed.
thanks a a lot guys.
- Status
- Not open for further replies.