[JohnH]

I have recently added a second zone to my home theater setup using the multi-room feature of my Marantz SR-7000 receiver. I have the Marantz connected to a Parasound HCA-855 amp, to a pair of B&W WP-1 speakers. When I turn the Parasound on, and then turn on any of my source equipment (DVD, CD, VCR, etc.) that are connected to the Marantz, I hear a loud buzz through the second zone B&W speakers. The odd thing is that when I turn off the source equipment, the buzz continues for about 20 seconds and then disappears. The tone and volume of the buzz are also affected by whatever is playing on the source equipment (flipping the channels on the TV clearly alters the tone). I suspected a ground loop, but disconnecting the CATV has no effect. My interconnects are decent (Audioquest Sidewinder, XLO Twinax) although they do travel past several power cords (at right angles as best as i can manage). I have no problems with any of the other equipment when the Parasound is turned off. All are connected to a Monster surge strip to the same outlet (other than a powered subwoofer that is not the problem either). Any ideas? I have tried a search but can't seem to find a thread that replicates my problem.

 

[David Richardson]

Is the Parasound anp wide open with the marantz multiroom volume controlling the volume of the speakers?


Dave

 

[David Richardson]

Is the Parasound anp wide open with the marantz multiroom volume controlling the volume of the speakers?


Sounds like the MR outs are not buffered enough and you have bleed thu from the sources.


The solution depends on the answer to the above question.



Dave

 

[JohnH]

David - yes, the gain on the Parasound is all the way and I am controlling volume via the Marantz. Also, the buzz disappears when I disconnect the interconnect between the Marantz and Parasound.

 

[JohnH]

Anyone have any ideas?

 

[GBishop]

1 or both channels

if 1 channel try swithching the interconnects between the Marantz and the parasound

if it stays in the same channel you know it's the amp/speaker wire/speaker

if it changes (l to r or visa versa) it's before the amp

 

[David Richardson]

Sorry been working on a project.


This is an adjustment that I would start with.


1) turn the MR volume to -5.(almost full volume)


2) turn the parasound amp gains down all the way.


3) put some loud cd in and slowly turn up the gains on the parasound until it's as loud as you need it.


4) You just set the max output. Check to see iif that took care of the problem.


other options:


1) Insure the parasound and marantz are plugged into the same outet.


2) tie a 14awg or 16awg speaker wire to the case of the matantz to the case of the parsound via case screws.



Lets us know what happens.


Dave

 

[David Guill]

Try using a cheater plug (converts a 3-prong plug into 2-prongs). This should break any ground loops which you may have

 

[JohnH]

Thanks for the suggestions, I will try them out tonight. I assumed the cheater plug would not help since both the Marantz and Parasound are plugged into the same outlet, but would it make a difference if the Parasound has a three prong plug and the Marantz a two prong (I know the Parasound is 3 prong but I'm not sure about the Marantz)? David, would your first suggestion eliminate the problem or just mask it? In other words, would whatever it is thats causing the buzz continue to impact the sound quality in the multi-room even though you can't hear a buzz when nothings playing?

 

[Dennis Erskine]

That's been a common event for me with Parasound amps (doesn't mean they are good amps), and lifting the ground with a cheater plug has solved the problem all the time. I'd run through the other suggestions and use the cheater as the last resort.