Buzzing/Humming Sound VM

[WAKI]

Hi guys, just setup the Formuler F1 box last night and very pleased with it all after some recommendations on here, however I have noticed there is a humming/buzzing sound coming through the audio when the VM cable is connected which is odd as I have never had this issue with any other box before (Picture etc. is all fine).

As soon as I remove the VM cable the sound stops and reappears when connected/touched to the RF/cable input on the box. Any suggestions or could it be a duff box?

 

[steptoe]

Audio via ?
HDMI?
TV?
Surround sound?
Sound bar?

 

[WAKI]

Box connected via HDMI, then sound is outputted through to sound bar via optical. Tried connecting the box directly via optical cable to sound bar and TV, but still same. As mentioned the buzzing/humming sound stops when I disconnect the VM Coax cable.

 

[steptoe]

Try a different HDMI,
Could be induced.
And check audio settings on box.

 

[grog68]

turn sound bar off and try sound via tv speakers

 

[steptoe]

turn sound bar off and try sound via tv speakers

says he tried that in post #3

 

[grog68]

says he tried that in post #3

'Tried connecting the box directly via optical cable to sound bar and TV'

Doesn't say he's tried taking soundbar out of equation all together.

 

[steptoe]

'Tried connecting the box directly via optical cable to sound bar and TV'

Doesn't say he's tried taking soundbar out of equation all together.

ah
yes, so I've made an ass of ME
when he said to TV I just assumed,,,,,,,,,,,,, not good

 

[WAKI]

Yeah I tried different HDMI, Even disconnected the soundbar etc. which didn't make a difference.

But I've sorted it out after taking it back to basics and looked into all the VM wiring coming in. It turns out there is an issue of ground noise/isolation from the incoming feed which has not been addressed by using an attenuator which I thought was added during installation (in this case it clearly hasn't). Therefore, I used an attenuator from the in-laws house and fitted this directly to the incoming feed and then connected the splitters back up and surprise surprise the noise has now totally disappeared. Take the attenuator off and the noise/hum returns.

The H2h box and other boxes didn't experience this issue with the attenuator missing/not being fitted.

Good learning curve I suppose and hope it helps someone out in the future.

Thanks for the replies/suggestions guys, helpful as always Steptoe and grog68 :)

 

[grog68]

pleased you have figured it out