Faulty Alchemist CD player to transport

[adrianjones]

Hi
I have an Alchemist Nexus MKII cd player that plays cd's but has a relay click between tracks. I guess it is a muting device. The CO-ax output also does not work. I spoke to the guy who designed these and he suggested a power supply fault.
I have now bought an Alchemist DAC and want to use CD player as a transport, so need to fix it. The diodes in the supply section seem to check out ok. I am now thinking of changing the caps in the supply. Any advice would be helpful.
Alternatively, could I use the supply from the digital mechanism (Philips Eco) with a custom circuit to provide better quality output?

[Mooly]

You would need to come up with a circuit really.

PSU fault mentioned... so is it a common fault ? were they not more forthcoming in any details.

Coax doesn't work... you need to hang a 'scope on there and see what it shows. Can it be turned off via software i.e. front buttons. Check all the rails for noise and ripple with 'scope.
Is the relay click a physical relay within the player ? or do you mean a click on the audio output signal between tracks that sounds like a relay.

The contributer to this thread says he has connections to Alchemist.
Alchemist Maxim APD-30-A schematic

[adrianjones]

Thanks for the reply.

I spoke to Chris Found some time ago. He designed this machine, and wanted about £180 to fix it. So, I did not bother as it plays ok as a cd player. But now I want to use the digital co-ax output.

It is a relay inside that clicks. Nothing through the speakers. It clicks at track end, then again at track start.

[stephensank]

Except spmetimes for optical, digital out is rarely driven directly from the DSP chip, so, assuming you have or have access to an oscilloscope, it should be fairly easy to follow the line back from the output jack to find the failed pulse transformer, capacitor, resistor or basic logic inverter(usually some form of 74HC04 or 4069) chip, which is just about all that will be between output & dsp chip.
As for the relay, which is almost certainly an analog muting relay, it should do no harm whatsoever to simply remove it.
Although I see from photos of the innards of the mkI player that it uses Rubycon caps in the power supply, they are a bit young to start dying yet, although I would not rule it out by any stretch. If there are any Elna, Panasonic/Matsushita or Nover(as Brits seem fond of using), then bad caps is far, far more likely.