This is my current system:
Samsung HLP-6163 DLP TV
Marantz SR-18 receiver
Denon 3910 DVD player
Atlantic Technology 370THX Ultra 5.1 Speaker system
Monster HTS3500 power conditioner.
cables and speaker wire from Monster and Blue Jeans cable.
there is also a cable connection that goes to my power conditioner and from there to the TV.
For the last six years, I've had my Marantz receiver and Atlantic Technology speaker system. I connected to it using coax digital input from various DVD players.
Recently I bought Denon 3910 and having decided to go into multi channel audio, I also bought 6 channel analog cable from Blue Jeans cable.
Yesterday, I plugged in those cables and started listening to music using Marantz's six-channel direct mode (for the first time). I immediately became aware of a hum from all the speakers, and it was evident from my seating position 7 feet away from the mains.
I switched back to the digital coax input, and the hum was significantly reduced. In fact I was only able to hear it by putting my ear next to the speaker drivers. I then unplugged analog and digital cables to the receiver from all sources and just turned on the receiver...again hum, is not audible from seating position, but I am barely able to hear it when I put my ear to the drivers of the speakers. Now... I am not even sure if it wasn't always there... From quick scan of the internet, it looks like it might be a ground loop problem. The only thing is, my power conditioner light says that grounding is ok... I don't know how reliable that is.
So my questions are:
1) is it normal to hear some minimal noise/hum through the speakers when the receiver is on but not playing? Or are they supposed to be dead silent?
As an aside, Marantz SR-18 got very high marks in a review several years ago from this very site.
2) why would there be a difference in hum level between analog and digital connection?
Tomorrow, I am going to start checking my wiring and trying to isolate the problem further, but if anyone has any advice, it will be greatly appreciated.
Thanks in advance,
Stan
