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MX120 Hum Problem

clarbin

Member
Banned
Got around to installing my new MS750 and MX120 yesterday into my system and I am experiencing a humming coming from my 2 front speakers only.

I tried isolating everything I could getting down to only having the pair of MC501's connected through balanced cables.

The hum is still there. Even with the MX120 turned off. Not as loud but still there.

When switched on, the hum is not effected by volume, it stays the same.

I even tried switching over to unbalanced cables with no improvement.

I changed power cords. Bupkis.

After battling this thing for hours, I finally gave up and hooked up my old Sunfire unit with no hum whatsoever at all.

Help!
 
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Most likely a ground loop problem somewheres. They can be a SOB to isolate, I know...been there, done that...
Start by unplugging all sources from the MX. If it's still there with just the MX & amps, try one of those cheater plugs that lifts the ground from the AC plug. Good luck & patience, you'll get to the bottom of it...
 
I had this happen to me as well. I was able to resolve it by switching to shielded power cords and by using Shunyata and RGPC rpoducts. Check to see that your power cords are not near your speaker cables. You might be getting hum from the powercords.

My system is super quiet now.
 
I got down to having only the amps plugged in and it would still do it even with the MX switched off.

I am going to try a cheater plug on the MX but everything that I am reading says that I'm going to get electrocuted if I do this.

So now I don't know.
 
Well I guess the search function is your best friend.

Thanks for all the responses to the 100 other threads about hum.

Gonna try the cheaters when I get home, but what is it about Mac equipment.

Is it more sensative to this problem than other brands?

My Sunfire has no issues at all.
 
humx.jpg


This did it for my MX119
 
Well I put a cheater plug on the MX to no avail.

Turns out that it's my 2 sat connections going to my hi-def sat/dvr box.

I unhook the cables from the wall and viola, no hum.

Now, what to do about these satellite cables, any suggestions?

I'm just leaving them unhooked until I get a solution. I have lots of DVD's and music to listen to until I figure it out.

By the way, except for trying to figure out the setup and this remote, the MX120 is a beaut.

It kicks the crap out of the Sunfire as far as sound quality goes. Minus the hum.
 
IF the DirecTV install was done correctly, the coax from the satalite dish SHOULD have been grounded, but quite often the installers cut corners. The add on filters & cheater plugs ought to be considered temorary work arounds...they only mask the proplem, & shouldn't be a long term solution. Just my $.02..
Glad you ID'd the problem...
 
I had a satellite install company at my house today. It turns out that everything coming into the house is fine. The problem is coming from the DirecTv HD DVR.

If I unhook it and replace it with a regular HD box, gone hum.

The power cord on the DVR is a 2 prong and on the reg HD box it's a three.

I don't know if this matters? I don't think so.
 
I wonder of you grounded the chassis of the DirecTv HD DVR box if it would still hum? (affix a wire from a chassis screw on the DVR to the ground on the back of your MX-120)

I had the hum problem and it was a hassle getting it resolved, but once it was, everything was perfect!
 
One more time....

It is against the National Electrical Code and every state's contractor's licensing board to install cable or satellite systems in a home and NOT be at the same ground potential as your electrical service. The ground must be the same and all services must be grounded at the entry point, your fuse box, ground.
If your cable company will not correct the faulty installation, we know it is faulty since you have hum when their gear is connected, just call the state licensing board. You will find this works best to stimulate repair.

Thanks,
Ron-C
 
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