Loud humming when connecting Xone:23 to amplifier

[Jeremiah MParticipant]

Hi,

I just got a new Xone:23 mixer after replacing my Xone:22 of many years (the power connector would not hold). When I connected the Xone:23 from its monitor RCA output to the RCA input on my amplifier (Onkyo TX-8255), the same way as the Xone:22 was, a quite loud humming noise started coming from the speakers even with the Xone:23 powered off and the amplifier set to a different input. The RCA cable is away from most of the other cables. Setting the amplifier to the Xone:23 input made the humming noise slightly quieter.
I’ve ordered XLR female to RCA cables so hopefully that connection won’t have the same problem. Other than that, is there anything else I can do?

Thanks,
Jeremiah

[Mike CParticipant]

Disconnect all the inputs from the mixer and see what happens.

Make sure you are not connecting to the phono input on the receiver.

[volounteerParticipant]

@jeremiah M

It is absolutely mandatory to have a good ground from a TT to the chassis of the x123.
After that there are ways for properly connecting kit to a power source to help avoid hum.

[SteffenRParticipant]

the power connector would not hold

to repair this costs 5€ (7$)… sorry could not withstand

I’ve ordered XLR female to RCA cables so hopefully that connection won’t have the same problem.

the connection to the amp is not the problem I guess…it will not change

[Jeremiah MParticipant]

to repair this costs 5€ (7$)… sorry could not withstand

You’re right. My plan is to repair the Xone:22 and sell/give it away. I’ve had it since 2011.

the connection to the amp is not the problem I guess…it will not change

You were also right. The XLR cables didn’t do anything, but they are nicer than the RCA ones. It turns out that the 1/8″ ->RCA cable connected from my TV to the receiver/amp was the culprit of the humming. When I disconnected it, the noise went away. No combination of connections and eliminating ground loops would make it go away unless I unplugged that cable. I probably need a better way of getting audio from the TV.

So for now I have the inconvenience of having to alternate between having the TV output plugged in and the Xone:23 plugged in, but at least I can happily mix.

Thanks for the help folks.

[Mike CParticipant]

Ah! You didn’t mention the TV connection in your first post.
You just have a good ole fashion ground loop between the TV and the rest of
the system, my guess is if you connect the TV directly to the Onkyo it would
hum as well.

A TV can lots of points for grounding, power, cable system, satellite receiver.

You need some transformer isolation between the TV and the mixer.
Something like one of these….

Rolls

Kopul

ART

[SteffenRParticipant]

or try to connect the TV to the same power socket as the receiver and put the mixer on that as well

[Jeremiah MParticipant]

Everything is on the same surge protector except for the TV which doesn’t have a long enough cable. I’ll try extending it and plugging it into the same connection. I don’t remember 100% but I think the problem was still happening even when the TV power was not connected.

[Mike CParticipant]

I don’t remember 100% but I think the problem was still happening even when the TV power was not connected.

Even unplugged from power but still connected to other sources the TV could still cause
hum from grounding issues.

[volounteerParticipant]

@JeremiahM

you need to learn the basics of electronics and what causes hum

[Author]

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