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Discussion Starter #1
I have a Denon 3803 that I am using as a pre, combined with an Outlaw 7700 amplifier.


If I hook up a digital coaxial cable into one of the digital coaxial inputs on the back of the Denon, regardless if it is hooked up to a source (DVD player, Tivo) it causes the ground loop hum into the amp.


Before I take it in to the shop and get charged a ton to "troubleshoot", is this something that could be easily fixed, or could there be some kind of compatability issue with the RCA pre outputs and the digiatl coaxial inputs?


I prefer the use of coaxial cables to optical only because the cable seems to fit more secure into the plug.
 

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Did you go through the "Hum FAQ" sticky in the Audio theory, Setup and Chat forum?


My guess is the all-to-common CATV-induced hum.


Read the FAQ and try the suggestions/advice listed there.
 

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Discussion Starter #3
While I had not checked that sticky, I have done a lot of troubleshooting just like mentioned in that post.


I do have satellite from DirecTV. When everything is unplugged from the Denon, there is no hum. If I plug in a digital Coaxial into the Denon, the hum appears.
 

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You just plug the cable into the AVR and not the source and the hum starts?


Strange, plug in just a basic RCA cable and see if it produces the same result.


This is a bit of an odd ground loop, I suppose the cable could be bad. 99% of the time hum is caused by the Sat or Cable no tbeing grounded properly.
 

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Discussion Starter #5
JD,


Yes, everything is unplugged except the RCA cables from the Denon to the amp. There is almost no noise whatsoever coming from the speakers. There is a very very very faint buzz but only audible if you have your ear right at the horn tweeter (Klipsch RF7s).


Plug in a rca digital coaxial into one of the 2 inputs and BAM, BUZZZZZZZZZZZZZZZZ!. Unplug it it goes away. Plug in a RCA cable into one of the 5.1 anaologue inputs and same thing.


The TV, Satellite, sub, all is unplugged and disconnected from power.


I am running a Monster Power 2600 to provide "clean" power. I unplugged that and plugged the amp and Denon into a different outlet and no relief.
 

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I am at a loss. If all cables produce the effect, I would say your digital coax input is hosed, as in toast, broke.


Really not sure, this is not your normal ground loop buzz.
 

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Quote:
Originally Posted by cp1966 /forum/post/0


JD,


Yes, everything is unplugged except the RCA cables from the Denon to the amp. There is almost no noise whatsoever coming from the speakers. There is a very very very faint buzz but only audible if you have your ear right at the horn tweeter (Klipsch RF7s).


Plug in a rca digital coaxial into one of the 2 inputs and BAM, BUZZZZZZZZZZZZZZZZ!. Unplug it it goes away. Plug in a RCA cable into one of the 5.1 anaologue inputs and same thing.


The TV, Satellite, sub, all is unplugged and disconnected from power.


I am running a Monster Power 2600 to provide "clean" power. I unplugged that and plugged the amp and Denon into a different outlet and no relief.

Have you tried different cables?
 

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Quote:
Originally Posted by whoaru99 /forum/post/0


Have you tried different cables?

Digital Optical, for instance??
 

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Discussion Starter #9
Just to give a long overdue update;


After talking with Outlaw, they believed it was in internal part with the amp. They took thew amp back and sent me a new one. I also bought the Outlaw 990 preamp to replace the Denon, and I bought balanced cables offered by Outlaw.


The result;


WOW!


No hum, and the 7700 really made my Klipsch RF7 and its little brother n sisters sing loud and proud!


The only bad thing is the 990 has no HDMI inputs.
 
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