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View Full Version : Fixing my Arcam Alpha One Amplifier



routercnc
15-12-2025, 08:15 AM
This has been on my list for a long time - well, it's now at the top so lets give it a go.
The issue was the right channel was not working, so more of a mono than a stereo. I managed to download the service manual from 1998 which included the circuit diagram but it looked so complicated!
I've got a scope, multimeter and misplaced confidence so how hard can it be?


https://youtu.be/VJYAkkLQCcU

Muzzer
15-12-2025, 11:58 AM
Intermittent faults with indeterminate fixes are always a concern, as you can never be certain you've actually identified and corrected the root cause. Fingers crossed you don't find this coming back again, not least during the Festering break! Your switch cleaner may have been the strongest bet. Just don't touch anything!!

routercnc
15-12-2025, 04:22 PM
Intermittent faults with indeterminate fixes are always a concern, as you can never be certain you've actually identified and corrected the root cause. Fingers crossed you don't find this coming back again, not least during the Festering break! Your switch cleaner may have been the strongest bet. Just don't touch anything!!

Yes it would have been nice to find something faulty. I’m going to assume a bit of dirt in the volume pot on the right channel that got dislodged when I took it apart. I ended up rotating the whole amp several times getting to screws and so on and maybe disturbed something. Finding something would have made a better / helpful video but here we are. At least if it stops working again I know a bit more about how it works.

Muzzer
15-12-2025, 05:20 PM
Indeed, and the service manual seems pretty comprehensive and freely available. Interesting to see the components are readily available ie nothing exotic - and why should they be. Even the output MOSFETs are industrial IRF540.

routercnc
17-12-2025, 11:33 AM
Right, time to sort out the skipping CD player.



https://youtu.be/RkbyaTZewD0