Need Help with a vintage amp power meter problem

Audiolab 6000CDT Dedicated CD Transport

santoshmanivannan

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I acquired an audio source one amp + preamp some time ago. The unit has power meters for both left and right channels but the right channel meter seems to be stuck and not moving. Is there any way of fixing the meter? Please do suggest any professional in Bangalore that can help me with this. Thanks in advance!
 

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I acquired an audio source one amp + preamp some time ago. The unit has power meters for both left and right channels but the right channel meter seems to be stuck and not moving. Is there any way of fixing the meter? Please do suggest any professional in Bangalore that can help me with this. Thanks in advance!
It can be a diy fix too. The power meters are drived by a circuit which contains a preset, try adjusting the preset and see.
 

reubensm

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I acquired an audio source one amp + preamp some time ago. The unit has power meters for both left and right channels but the right channel meter seems to be stuck and not moving. Is there any way of fixing the meter? Please do suggest any professional in Bangalore that can help me with this. Thanks in advance!
by stuck and not moving - i assume the needle remains in the same position when the amp is off as well as on - if this is the case, the meter itself will need to be checked. At times, these VUs may get stuck/ceased/jammed and can be easily fixed by opening them up and simply freeing the needle assembly. In some cases, i have noticed that the stuck needle is due to physical damage, something breaking or bending. If this is the case, then one can attempt to repair or simply replace.

If the needle returns to null position when off and is stationary at the position shown in the photo when turned on, then you will have to troubleshoot the circuitry which is wired to the meter (the meter coils and not the bulb/LED). If the meter itself is mechanically and electrically ok, then you have the working channel for comparing voltages to.

Additional info: The process for diagnosing issues with electronics is similar to a doctor's diagnostic methods when we report sickness. More complete information on the symptoms, or operating conditions when the issue was first noticed, a more detailed description of the issue, etc would be very helpful for the exact 'prescription of treatment' which in this case, is the fix :)
 

santoshmanivannan

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Joined
Feb 5, 2021
Messages
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Location
Bangalore
by stuck and not moving - i assume the needle remains in the same position when the amp is off as well as on - if this is the case, the meter itself will need to be checked. At times, these VUs may get stuck/ceased/jammed and can be easily fixed by opening them up and simply freeing the needle assembly. In some cases, i have noticed that the stuck needle is due to physical damage, something breaking or bending. If this is the case, then one can attempt to repair or simply replace.

If the needle returns to null position when off and is stationary at the position shown in the photo when turned on, then you will have to troubleshoot the circuitry which is wired to the meter (the meter coils and not the bulb/LED). If the meter itself is mechanically and electrically ok, then you have the working channel for comparing voltages to.

Additional info: The process for diagnosing issues with electronics is similar to a doctor's diagnostic methods when we report sickness. More complete information on the symptoms, or operating conditions when the issue was first noticed, a more detailed description of the issue, etc would be very helpful for the exact 'prescription of treatment' which in this case, is the fix :)
Thank you for the reply and sorry for not including as much info as needed in the OP. The issue is only with the meter, there is no channel imbalance etc.. The right meter has an offset where it only starts at a little higher than 0. And the needle doesn't move, by which I mean it shows some motion when music is played which correlates to the left VU movement but it only pulses and doesn't move so I think the meter is electrically good but mechanically, the movement mechanism has a problem.

Additionally, the preamp unit that I have of the same company also has issues so I have to get both of them fixed. The preamp has a bad input selector and a channel imbalance as well (not related to the input selector, just in general).
 
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