Buzz on Pioneer A400

[Smiffy]

Hi All
Trying to cure a buzz on a Pioneer A400 amp.Its there on all inputs.It is not there if there are no inputs(nothing connected)I have tried 4 sources(Pioneer laserdisc player,Sony dvd player,Pioneer dvd player and Faroudja dvd player)The only thing earthed to the mains is the A400.I have tried different interconnects.The buzz rises in level as the volume is raised(with source on pause).Have a schematic.Any ideas where to start anyone.Thanks for any inf.Smiffy

 

[anatech]

Hi Smiffy,
Try connecting a source that is not connected to a television or anything else (like cable).

-Chris

 

[Netlist]

A bad soldering or broken ground track around the inputs is my guess.

/Hugo

 

[Smiffy]

Hi Guys
Chris.
I tried the amp with only one input.The dvd players or laserdisc player.Nothing else was connected.
Hugo.
Will check later.
Ta both of u for reply
Smiffy

 

[anatech]

Hi Smiffy,
Therefore, I agree with Hugo. It sounds like an open ground somewhere.

-Chris