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View Full Version : ground-loop hum or bad transporter?



twu
2010-02-23, 01:40
I'm a long time owner of three SB3 and one Transporter but this is my first post. I've searched and found a couple threads pertaining to ground-loop problems but none of the suggestions have help so I'm wondering if I just need to get my Transporter serviced.

I'm currently using my Marantz SR7001 receiver with my Transporter, that's worked fine without any noises. I've recently started auditioning other amps/receivers using Transporter as the source and I'm hearing a low hum with all of the amps/receivers that I've tried. When I use my SB3 with the amps, it's fine, no hum. Everything seems to point to a ground-loop problem right? But when I tried the cheater 2-prong adapter, I still hear the hum. When I unplug all other components from the power-strip, I still hear the hum. I even tried the Hum-x adapter which works for my sub-woofer but it's not working with the transporter.

So far, here's what I've found...

TP --> Marantz SR 7001 (ok)
TP --> NAD receiver (hum)
TP --> Vintage Marantz 2220b receiver (hum)
TP --> Bryston 3B amp (hum)
SB3 --> all the above (ok)

I'm out of troubleshooting ideas. Any help/suggestions would be really appreciated.

osama
2010-02-24, 10:29
This is an issue that our technical support team can assist you with.

I recommend sending an email to support for additional assistance with this matter.

Please follow the link below the click on the Email Support link.

Please be sure to select the correct product in the product selection drop down menu.

Audio > Network Music Players > then select the correct Squeezebox product you are requesting support for.

http://www.logitech.com/index.cfm/support_downloads/&cl=US,EN

http://www.logitech.com/index.cfm/support_downloads/&cl=US,EN

Ron Olsen
2010-02-24, 11:54
I had a hum problem with my Transporter and it turned out to be caused by the TV cable. I installed an isolation transformer (Jensen VRD-1FF Cable TV RF Isolator) on the TV cable and the hum went away. A SqueezeBox Duet in the same location produced no hum; just the Transporter.

See http://www.audioholics.com/tweaks/connecting-your-system/ground-loops-eliminating-system-hum-and-buzz for details.

You can test if this is your problem by disconnecting the TV cable from the wall outlet and seeing if the hum goes away.

twu
2010-02-24, 18:16
Ron, thanks for the suggestion. I tried that too and it didn't work for me. I have a distribution box that feeds the Cable TV line into all the rooms, do I need to disconnect the main TV cable line or just the one in the room that I'm having the problem?

I'll try the steps in the article, I'm also using a dimmer in my room so I'm going to look into that.