[mythtv-users] Slightly OT: receiver input buzzing/humming

Steve Adeff adeffs at gmail.com
Wed Jan 11 02:44:04 UTC 2006

On Tuesday 10 January 2006 21:22, matthew.garman at gmail.com wrote:
> I've got a Yamaha HTR-5550 receiver that receives input from (among
> other places) my mythtv box. This is an analog input: the cord is a
> male 1/8" stereo plug (PC side) that splits into two RCA connectors
> (amp side).  The motherboard is the Chaintech 7NIF2.
> Recently, I've noticed that when I'm not playing music or watching
> TV (i.e. silence), there is a distinct buzzing/humming sound coming
> from the speakers. The sound is barely noticeable at the "-40.0"
> volume setting, and quite pronounced by "-30.0".
> I've tried messing with the volume levels on the PC; it does not
> make a difference in the buzzing. I've tried re-seating both ends of
> the cord (to no avail).
> Note that when I switch input channels on the amp, the buzzing goes
> away. So I tried putting the RCA plugs into a different input---no
> help.
> For what it's worth, the buzzing sound is the same as if I pull the
> 1/8" plug out, and touch it to my finger---I'm sure this is a
> familiar sound to many people.
> My guesses are that either the cable is bad (it's an el-cheapo,
> don't know where it came from) or the input jacks on my PC are
> crummy or not properly grounded. This sound is the kind of sound I
> would expect when my plug isn't properly seated, but, as I said,
> I've tried seating and re-seating it several times (across the
> different outputs), and still have no success.
> Does anyone have any suggestions on my next steps to further debug
> this problem?
> Thank you!
> Matt

welcome to the world of ground loops!

Are the computer and receiver plugged into the same socket/extension strip?
 if not, make sure they are.

Does the receiver have a 2 prong power plug? if so, run an independent wire 
from the receiver case to ground.


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