Hi,

I've had my 7100 for a couple of weeks now and I'm very pleased with it but there is a hum coming from it. It is not noticeable when I am watching a movie or listening to music but it is a little iritating when nothing is playing. Has anyone else had this issue with the 7100. Could it be a ground loop? I'd appreciate some feedback. Thanks.

Most likely it is a ground loop... you can start unplugging things from your preamp until it goes away.. that would at least let you know what's causing it....

My 7100 has a hum, too. It doesn't output the noise thru the speakers, so it's not a grounding problem -- the humming/buzzing comes from inside the cabinet after the unit has been powered up for a couple of hours.

It's not loud, but it can be heard without straining. Hmmmm...if it gets any worse, I'm going to have to use the warranty.

Spencer, your transformer humm is probably from dirty power, you might want to look into a power conditioner or the AC Offset Killer from Ah! available from upscaleaudio.com. They have a 15 day trial for the offset killer and you can test it out to see if it fixes your problem.

If you have cable TV, and use a cable box- I'd check that first. They are probably responsible for most of the ground loop system's hum out there. To check, just disconnect the coax cable from the box and see if it goes away-- best wishes!

[This message has been edited by steves (edited May 07, 2003).]

They are probably responsible for most of the ground loop system hums out there

I've seen at least 3 guys fix an issue like this in the last few months by discovering that the cable/sat installer set a seperate ground rod for the cable during install which can create the noise. If the noise occurs with this method, - The cable should be grounded to the main ground rod for the house which is usually nearby. A fourth just found that his clamp was loose and the cable was not tight to the rod, snugging got rid of it. It's one of the quickest fixes to eleminate.

Two different types of hmmm and they are being confused here. Hmmm from the cable or ground loop or bad plug grounding is evidenced by it being audible thru the speakers and this hmmm is being introduced on the ground floor of the sound being processed.

Hmmm like Spencer is describing is known as transformer hum, it is caused by the 60Hz signal vibrating the windings of the transformer, hence you hear the hum from inside the chassis. Toroid transformers are known to hum from bad AC, hence the recommendation I made to check the power.

Outlaw appears to use pretty high quality toroidal transformers from the pics i have seen of them on the web, but then again, one could be defective or your power could just be really nasty.

Alphanstein -- I ordered the Ah! unit from upscale. Hopefully, it'll do the trick.

Thanks for the tip!

I just got my 950+7100 and connected it all. I have exactly the same problem, 7100 hums loudly. I had really good luck with 1050, that unit was silent when no signal was sent to. I tried Denon 3803 and it did not make any parasite noises either.
I ruled out Ground Loop by simply unplugging my speakers. I can easily locate the noise, it sounds like the old transformer. Somehow, I am not buying into the idea of bad power because neither Denon nor 1050 made any noises, and they were connected to the same AC outlet. I do not feel that I need to spend $400 on AC conditioner to get 7100 to work for me.
Is Outlaw exchanging 7100?

Umm...unless you have power cables crossing all over your speaker cables this won't rule out a ground hum. You really need to unplug inputs into the 950 one at a time to figure out the where a ground hum would be coming from.

If the amp itself hums, I would think it would do it by itself with absolutely nothing connected either in or out of it. If this is the case, I would definitely be contacting Outlaw at this point.

One other little thing; I corrected a ground hum in my system with an in-line surge protector/ground lift on the the coaxial RF line. My local dealer gave it to me for free but I can't imagine it costing anymore than 10 bucks.