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I Need Help

Hi All,
I recently purchased a used Denon AVP-8000 along with the matching amps POA8200 & POA8300. I was told that this thing was just like new. Yea it looks good but not playing like one. I have experienced a buzz, very low but audible, from the center channel only which also gets louder if the unit is played for a extended time ( I think, for you see, Denon has had this longer than I have and I really can't remember). I do remember my wife is ready to kick my ASS if I tear this house up one more time rewiring and etc. It has been to Denon service twice since May and they have not fixed a thing and I have just sent it to them for the third time about 3 weeks ago. First they told me they replaced boards inside the unit(3 of them to be exact) and said it was OK. Hooked it back up and the buzz was still there. 2nd time they replaced another board and said it was fine and guess what?..same buzz. I have done about everything imaginable and now I am lost. Spoke to Denon yesterday and they are going to look at it one more time. They have been looking for 3 months now and still can't find the problem. I was told by them that this noise may be generated by house current and/or may be normal and that all digital equipment has some type of noise generated through the outputs.Swirling, hissing, warbling... PLEASE! If that's the case then why aren't all the speakers buzzing? It is only coming from the center when played in any 5-ch. mode.If I move the center channel output from the pre amp and plug it into ...say right rear input of the amp..the buzz goes to that speaker. Am I missing something? Is there a problem in my house wiring that could only be triggering the problem out of the center channel only? I am using Klipsch R-3 series center and surrounds if it makes any difference.
skin_54

Showing 1 response by bear

bear
141 posts
 
Do this:

With the power OFF for all of the amps except for the
center channel - listen... IF it is still buzzy. Unplug
from the wall, each amp's AC plug and see if the bzzz goes
away.

alternately, take the center channel output with the other outputs NOT connected at all and listen.

IF still there, disconnect ALL the other inputs to the device that is generating the 5 channels of junk sound and see if that makes the buzz go away.

IF it is still there, unplug the digital transport that is the source (and/or turn it off.

Point being this: IF it creates the buzz in the center channel in the 5.1 channel mode by ITSELF then it is not any sort of cable or ground loop.

The idea is to systematically eliminate everything one step at a time to isolate the causal factor.

It very well could be ground loop or simply bad decoding with digital noise in it (a defective circuit).

IF it is still buzzzing with nothing but the center channel amp connected, then try that output with a left or right channel amp connected to it. That will eliminate the amp from consideration IF it still buzzes, and if you use another interconnect (just swap it over) then the interconnect is not suspect either...

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