Hum that's driving me mad

[MosesMagnum]

Hi,

After a lot of moving stuff around and trying various sockets and extension cables I still have a hum.

The setup I have is as below.

Denon AVC-X4700 AVR

Devialet 200 Expert

MiniDSP 2x4HD

Connections are as below.

All 4 subs are connected to the MiniDSP which in turn is connected to the Denon via it’s SUB 1 output. The Denon pre-outs are connected to the Devialet for L+R, all other speakers are run from the Denon. The Devialet is connected to 2 of the subs using just the black wire from the high level cable.

The hum only appears when I connect either the high level inputs or from the Devialet sub out with an RCA to the MiniDSP.

If I use just the Devialet on it’s own for music with 2 subs connected via the high level connection there is no noise.

The Denon on on its own and everything connected, the noise is there.

Anyone have any suggestions?

Thanks

 

[fpitas]

Are the various pieces plugged into the same AC outlet? Or different outlets?

 

[terryforsythe]

Do you have a cable TV coax cable (e.g., RG6 or RG11 cable) connected to your system? That is where my hum came from. I found a power strip/surge suppressor that has a cable input and output, and this addressed my hum problem. Not all such power strips work, though. I have another one that is ineffective. If this is your issue, let me know and I will try to find the manufacturer/part number of my power strip that works.

 

[MosesMagnum]

No cable TV in use.

PC is connected to the Denon by HDMI and by USB to the Devialet, Blu-Ray player, Xbox by HDMI to the Denon. Denon and Devialet are connected by RCA's and trigger cable.

Everything is powered from the same sockets.

 

[sarumbear]

Hi,

After a lot of moving stuff around and trying various sockets and extension cables I still have a hum.

The setup I have is as below.

Denon AVC-X4700 AVR

Devialet 200 Expert

MiniDSP 2x4HD

Connections are as below.

All 4 subs are connected to the MiniDSP which in turn is connected to the Denon via it’s SUB 1 output. The Denon pre-outs are connected to the Devialet for L+R, all other speakers are run from the Denon. The Devialet is connected to 2 of the subs using just the black wire from the high level cable.

The hum only appears when I connect either the high level inputs or from the Devialet sub out with an RCA to the MiniDSP.

If I use just the Devialet on it’s own for music with 2 subs connected via the high level connection there is no noise.

The Denon on on its own and everything connected, the noise is there.

Anyone have any suggestions?

Thanks

Maybe you can post a diagram as I personally not sure how everything is connected.

 

[Snoopy]

Are those class D subwoofers?

U mentioned U use only the black cable of the high level input.

 

[MosesMagnum]

Apologies, let me see if I can explain it better.

Denon is connected to the Devialet by RCA's (Pre-out) and by a...

I literally got to that last bit and realised I had totally forgotten about the trigger cable between the 2 amps.

I just popped it out and hey presto THE NOISE IS GONE!

If anyone fancies slapping me round the head, please form an orderly queue.

Thanks for the help though.