Question Speaker hum caused by (disconnected) Arcam CD player

[BenStephens]

I have an Arcam Alpha 7 SE CD player paired with Arcam Alpha 6 amp, Beolab 6000 speakers and a Rega P3 (quite a mix!)

The CD player, even when not connected to the amp through RCA cables, is causing a hum through the speakers. Only stops when I unplug it from the mains power.

I took it to a hi fi shop when I bought the Rega and connecting it to their system was fine. No hum. Suggests there isn’t a fault with the CD player.

Any ideas? Thanks!

 

[Strider]

Might be a better answer from the technical bods but I reckon when the Arcam CD player (I once had a 7, 8SE and 9!) is disconnected from the amp that the ground is lost, possibly the CD player is causing ground loop.
If you have any of the RCA shorting plugs give those a go, I know NAD always supplied these with their amplifiers.
like this:
RCA shorting plug

These are fine all you need to do is cut a small wire and place in the spring terminals:
RCA Shorting plugs

 

[StingRay]

Are these 2 units next to each other?

You could try moving them further apart.

Check the wiring in the plugs, just in case the earth has come loose.

Do you have any earthing points on the back of these units?

 

[The Great Soprendo]

How loud is the hum? Is it the same regardless of the volume on the amp? I have an Alpha 7 CD player (upgraded to a 9 with the ring DAC module, but that's not relevant here) and it does seem to introduce some weird interference type noises into the system even when CD isn't selected on the amp. But you have to listen really close to hear it, sometimes with the volume right up beyond listening levels.

In fact, this applies (to a lesser degree) with the CD player switched off. Part of the circuitry on these remains on if it is just plugged in.

I'm not an expert by a long stretch but it's not unusual for a bit of radio frequency noise to be created and picked up somewhere in the system. Question is whether it's intrusive or not.

 

[StingRay]

How loud is the hum? Is it the same regardless of the volume on the amp? I have an Alpha 7 CD player (upgraded to a 9 with the ring DAC module, but that's not relevant here) and it does seem to introduce some weird interference type noises into the system even when CD isn't selected on the amp. But you have to listen really close to hear it, sometimes with the volume right up beyond listening levels.

In fact, this applies (to a lesser degree) with the CD player switched off. Part of the circuitry on these remains on if it is just plugged in.

I'm not an expert by a long stretch but it's not unusual for a bit of radio frequency noise to be created and picked up somewhere in the system. Question is whether it's intrusive or not.

1 post, last seen Mar 17, 2023. Maybe he has gone for good?

 

[The Great Soprendo]

1 post, last seen Mar 17, 2023. Maybe he has gone for good?

 

[Strider]

Ho-hum.

 

[Tazzo]

Maybe it could be the OP's mains?