Nasty HUM through my Onkyo Amp - PLEASE HELP!

J

jimihat

Guest
Hi

I've just finished setting up my Onkyo AV Receiver; I'm using KEF KHT 5001 satellite's and a Yamaha Centre & Sub.
Sound is great with music and action scenes etc but anywhere where there is little background noise (speaking etc) or no sound at all (flicking through menu's etc) there is a very audible electrical hum.

I;ve tired phono connection and optical connection straight from the TV, optical from DVD, and PS3 and get the exact same thing on all of them.

Do you think this is a fault with the amp or is this sort of thing common?

Would the problem be solved by getting a couple of these? High quality ground loop isolator: Amazon.co.uk: Electronics & Photo putting one between the amp and the sub and one between each input into the amp?

The problem is that I want to use optical connections for some of my devices?

:eek:PLEASE HELP:eek:

Thanks,

Jim
 

xmb

Well-known Member
You need to work out where the source of the hum is coming from first. Is it a ground loop or a faulty receiver?

If you disconnect everything from the receiver (including the sub) so only the mains lead and speakers (not sub) are connected can you hear any hum? Now switch to the radio on the receiver and listen for hum. If all OK then your receiver is OK, so move on to looking for the culprit!

Start by connecting the sub back in, is there hum now? If so the loop is between the radio aerial input and the sub (as both are probably grounded). To cure fit an aerial isolator (a wall plate that has isolated sockets (capacitors fitted in series with the centre and screen connections) rather than the normal direct through connections.

Any device connected by an optical lead will not cause a ground loop hum as there is no electrical connection! Continue connecting devices by RCA phono or HDMI one at a time until you locate the culprit.

Good luck.
 
J

jimihat

Guest
You need to work out where the source of the hum is coming from first. Is it a ground loop or a faulty receiver?

If you disconnect everything from the receiver (including the sub) so only the mains lead and speakers (not sub) are connected can you hear any hum? Now switch to the radio on the receiver and listen for hum. If all OK then your receiver is OK, so move on to looking for the culprit!

Start by connecting the sub back in, is there hum now? If so the loop is between the radio aerial input and the sub (as both are probably grounded). To cure fit an aerial isolator (a wall plate that has isolated sockets (capacitors fitted in series with the centre and screen connections) rather than the normal direct through connections.

Any device connected by an optical lead will not cause a ground loop hum as there is no electrical connection! Continue connecting devices by RCA phono or HDMI one at a time until you locate the culprit.

Good luck.
Wow, superb reply, thanks.

It's the receiver. I have nothing plugged in apart from the satellites and center speaker and still have the noise.

Does that mean it's faulty or is there something I can do?
 
J

jimihat

Guest
Does anyone know how to do a factory reset on this unit???
 

dante01

Distinguished Member
Does anyone know how to do a factory reset on this unit???
Hold down the 'VIDEO 1' button while pressing the 'STANDBY/ON' button. “CLEAR” will appear on the display and the receiver will then go into Standby.
 

daveh48

Well-known Member
Does anyone know how to do a factory reset on this unit???
It state's this in the manul for my Onkyo 507.....

To reset the AV receiver to its factory defaults, turn it on and, while holding down the [VCR/DVR]button, press the [ON/STANDBY] button. “Clear will appear on the display and the AV receiver willenter Standby mode"
 
J

jimihat

Guest
Gracias Amigos

I'm sending the unit back; I reckon it's a duff!!!!
 

xmb

Well-known Member
Bad luck on finding you have a faulty receiver, at least you can now be sure you have located your hum and hopefully will get a repair or replacement quickly.
 

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