Subject: Why would having 1800 Turntable connected to Beomaster 3000 produce humming in RL60.2 speakers when playing a record ?

The setup is..

The 1800 turntable with its two RCA wires and grounding wire are connected to the Beomaster 3000 using a 5-pin DIN adapter and the ground wire attached to one of the Beomaster's metal screws on its backside.

When playing a record on the 1800, a background low frequency hum can be clearly heard in both RL60.2 speakers.

Jiggling the speaker connections at the Beomaster 3000 did not in any way stop the humming sound.

Having the ground wire attached or not to the Beomaster 3000 did not affect the humming sound. It was present in either case.

With the 1800 connected to my Beomaster 3300 in the same way as for the Beomaster 3000, there's absolutely no humming to be heard.

What would you say the cause is for the humming when using the 1800 with the Beomaster 3000 ?

Thank you. 🙂