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**Solution** Ground loop hum (Read 4995 times)
RW82
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Posts: 45
**Solution** Ground loop hum
03/11/15 at 09:09:57
 
I decided today to change the way my subwoofer was integrated into my system.  Right now I am using a receiver with a sub out, and before today I was connecting my subwoofer via an RCA cable.  It worked, but since I got my Torii, it always bothered me.  I could never seem to get my subwoofer integrated with the rest of my system.   I always heard my mains, with a subwoofer.  I recently learned that using the high level inputs can be a much more elegant solution to a subwoofer.  Bottom line is that when using the high level inputs the signal being sent to your mains is the same one being sent to your subwoofer.  This is usually done without causing much strain on the amp since not much current is being drawn.  I saw a great improvement doing this with the Torii since all of the awesome things that the Torii does are transferred to my subwoofer; my mains and sub are now in "sync" so to speak.  Now all I hear is music.

The only problem I had was a ground loop hum that showed up between the Torii and my subwoofer.  I ended up using a trick that I learned a couple of months ago: I grounded the Torii and Subwoofer together.  This was accomplished by attaching a small wire from one of the chassis screws on the Torii to one of the chassis screws from the subwoofer.  My Torii had a slight hum prior to doing this, but now even that has been greatly reduced.  

I only write this because I had a hard time finding a solution to my ground loop, and I didn't find it on the "inter-web."  I hope it may be of use to someone else down the road.  The high level input trick was cool too I thought, but I am sure thats old news on most of these forums Wink.
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MBP 24 bit Audio via Oppo 103, PS Audio PWD Mk II DAC, Z-Stage, Pass Labs 30.8, Decware DM 947 Speakers.
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DBC
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Posts: 423
Re: **Solution** Ground loop hum
Reply #1 - 03/19/15 at 19:16:36
 
Quote:
RW82 wrote:

The only problem I had was a ground loop hum that showed up between the Torii and my subwoofer.  I ended up using a trick that I learned a couple of months ago: I grounded the Torii and Subwoofer together.  This was accomplished by attaching a small wire from one of the chassis screws on the Torii to one of the chassis screws from the subwoofer.  My Torii had a slight hum prior to doing this, but now even that has been greatly reduced.  


RW82,

I'm assuming your Sub has only 2 prongs on it's power cord (Power & Neutral, no Earth Ground)? Some Sub manufacturers do this to avoid ground loops that can be caused when plugging a sub into a separate power circuit from the amp or pre-amp. When using a line level connection (interconnect) the ground on the interconnect serves the same purpose as the wire you have run (grounding the sub to your amp).

You might find as I did that running that wire from your Sub Amp chassis directly to Earth Ground on your surge protection device will eliminate that last little bit of Hum. I used a simple test lead to ground my subs (see green & yellow test leads from the sub amp chassis to surge protector Earth Ground).

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Main System: Oppo BDP-105D, SE84UFO amp, Omega Super Alnico Monitors, Twin Custom SLAB 15's (Low Frequency Open Baffle).
Room #2: Oppo BDP-83SE, SE84CS amp, Omega Super 3i Monitors, Twin Custom SLAB 12's (Low Frequency Open Baffle).
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