Ground Loop/Hum Killer products - which one?

[Mozhoven]

I've got a nasty hum coming out of my speakers and would like to get rid of it. After doing some searching in my system I believe I've narrowed it down to my preamp/receiver (marantz sr5000). Not only do I hear the hum in my speakers, but I can hear an identical hum directly from the receiver. I should mention that I'm also using two Marantz monoblock amps.

Anyway, after looking at many different products on Ebay, I am at a loss for what to get.

On one hand you have a number of Jensen Transformers hum killers, but they are expensive at around $150.

On the other hand, there are a number of $6-$10 hum killers (raptor) that purport to do the same thing. My main concern with these products is that they employ their own wires to and from the unit. I've got nice interconnects and wonder if they would be compromised by these wires. Perhaps they can be replaced?

Anyway, I would like to keep this on the cheap if possible and not sacrifice any quality. Is this possible? I hoping this will be the exception to the "you get what you pay for" rule.

 

[monolith]

Does the problem go away when you ground the case of your preamp? You should figure out what kind of problem you have before throwing money at it, no?

 

[Mozhoven]

Sorry, but I am a bit new at this. Could you tell me how I would go about grounding my preamp?

 

[Uncle Erik]

Hook a wire to the chassis and connect it to ground. You can use the ground prong on a wall socket.

 

[Mozhoven]

Thanks, that's pretty much what I thought but I wanted to get a 2nd opinion before I go sticking things into wall sockets.

 

[johnsonad]

I was in the same boat not too long ago. I recommend going to the PS Audio website and use their "humbuster" tool. It will walk you though step by step on how to isolate your hum and what it is and give you recommendations on how to fix it.

 

[Know Talent]

Go to EquiTechs website and read the tech papers on ground loops...

Real solutions from people with REAL EE degrees that sell products that show measured results based upon proven methods...no snake oil

 

[Mozhoven]

I just checked out EquiTech's site and found it very informative. I've read a lot of other pages on the subject, but their's was the best organized and easiest to understand of the bunch. It's definitely given me a lot of methods to experiment with!

I've already tried grounding via the chassis into the AC ground plug with no luck. It does help a bit, but not enough to call it a success. I think I might try sinking some grounding rods into the earth and ground the equipment separately from the AC and see if that helps.

Since I am using a Preamp and two monoblock amps, I assumed I must ground all three. When I tried that earlier with the AC ground (all three into the same ground prong) the hum got much worse. Not sure what that indicates, but I went back to just grounding the preamp.

I'm using balanced power interconnects between the preamp and the amps, but I should mention they are not shielded (DIY TNT "shoestring" cables). The EquiTech article mentioned balanced cables are the way to go, so hopefully I'm covered there. Do I need to shield them? If so, how?

So, onto the other methods. Any advice will be much appreciated.

 

[greenhorn]

I had a similar (I believe) problem and I solved it (thanks to the advice received here) by turning the toroidal transformer by 90 degrees. More information here (and pics as well):

http://www.head-fi.org/forums/f5/hea...d-buzz-213036/

Good luck!