Denon X3700H and Amp? (nothing but hum)

[Tony Cardenas]

That is interesting. Units with two pin and not three pin are double insulated and safe.

The fact that bonding the Outlaw to your receiver solved the problem means that Outlaw has a problem in its ground plane architecture. That has to mean that the grounds on the input of that amp are not at the same potential as the case, and the power cord grounding pin. They should be. There is a definite design error in the ground plane architecture of that Outlaw amp.

Interesting - the Denon has a picture in the manual specifically referencing a phono input for the ground. Glad it works and glad it safe

"The earth terminal (SIGNAL GND) of this unit is not for safety grounding purposes. If this terminal is connected when there is a lot of noise, the noise can be reduced. Note that depending on the turntable, connecting the ground line may have the reverse effect of increasing noise. In this case, it is not necessary to connect the ground line."

 

[Tony Cardenas]

Well, the Outlaw amp manual did suggest that particular use of the grounding post to combat ground loop hum.....

Agreed - major slap on my forehead moment. If I had just used that (and your original advice) as my #1 I would have been here a lot quicker! Still - its a fantastic feeling to know that a somewhat custom system is now operational. I've never used an amp/separates before (used HK, Marantz, and Sony). Finally had the budget to do something a bit nicer. All in all its really sounding nice. And knowing electrically it isn't a cluster is equally a good feeling.

Many thanks

 

[stalag2005]

Grounding is as much an art as a science. We had a problem with a studio feeding back into the electrical lines for similar issues. One is not to hear the group Petra (I have the CD) in the managers office when I am playing it in a studio across the facility (rooms not next to each other). The solution was to bond all the equipment together and that eliminated the feedback. O, by the way, my partner was playing that CD in his studio without any interconnect........Audio can be strange! Those posts for ground is to bond the equipment together to relieve potentials between the circuits. In the case of audio ground it is not safety but to equalize potentials.

 

[Tony Cardenas]

Thanks stalag - it's reassuring to hear a story like that. That kind of sounds like the situation here (bonding both the Denon and Outlaw - removes the hum). Its something I wouldn't have thought about or considered - now it will be added to my 'tool bag' for future use.