I have n arcam 8R amp that is stuck on max volume even if i turn the volume knob down it still on max.
What would be the first thing you would look at?
I have three of them so I can swap parts.
Thanks
What would be the first thing you would look at?
I have three of them so I can swap parts.
Thanks
It's got to be the earth (0V) missing from the volume pot. Check the circuit track around the control it will be broken somewhere close. May even be a small crack.
Have the volume control 'floating mid air', signal in and wiper out connected with wires but the ground lugs connected to another ground point,
I guess #6 is mostly right.
I guess #6 is mostly right.
Ok I found the problem. If I remove this earth screw the volume seems to work ok. Now what do I do. Can I put a washer underneath this point and try to ground the chassis straight from the plug’s pin? It needs some sort of safety earth. If I connect the earth pin from the plug to the chassis the volume control still works fine so there seems to be something underneath that earth point.
Also underneath I do not see any cracks but again if I press down at the point of the earth then the volume gets stuck in constant volume.
Also underneath I do not see any cracks but again if I press down at the point of the earth then the volume gets stuck in constant volume.
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Do you have any device connected that uses an antenna input? TV, VCR, Decoder, receiver etc? Or one of those connected to the same power outlet/circuit? I had something similar, it was a ground/screen potential difference. I solved it first by disconnecting the coax antenna input and later with a ground loop isolator.
No I disconnected everything and it still does the same thing. Also I have 4 of these amps as I refurbish them and sell them on. None of the other ones do this thing after plugging them in at the same plug. It seems I can either put the front screws in and leave the main earth screw off or I can put the main earth screw and remove the front screws from the front bracket
Just grabbed this one from the net.
AudioCircuit
https://audiocircuit.dk › ...PDF
Arcam Alpha One/ 7R/ 8R/ 8P Amplifier Service Manual
AudioCircuit
https://audiocircuit.dk › ...PDF
Arcam Alpha One/ 7R/ 8R/ 8P Amplifier Service Manual
Ok found something more. When I connect the chassis of the main selector with the chassis of the amp then the white Siemens relay clicks and the volume goes constant.
So I basically cannot secure this selector with the chassis otherwise I have the fault.
So I basically cannot secure this selector with the chassis otherwise I have the fault.
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Try an ohmmeter search for conduction of selector bushing to signal path. I doubt there should be any conduction if all is correct. Compare with other units for comparison/sanity check.
Good luck!
Good luck!