Yup, I sent a support request to the Outlaws and they recommended running an extension cord to a different outlet to see if that helps the issue.

So I have to make a trip to Target to do this.

Will let you all know how that works out.

I just opened the cabinet and took a listen to my 7500, which has been on for almost half an hour. When I laid my ear onto the top of the cabinet, I could hear a faint transformer hum, but my ear had to be essentially touching the cabinet for it to be audible at all.

Yeah, I'm either going to have to get with Outlaw support to get a unit or just return the one I have for a refund.

I haven't heard any difference between the Outlaw and the B&K 200.7 so the annoying hum is currently the only real big differentiator between the two.

Thanks for checking your amps to see how much the power supplies were buzzing.

I agree that either there's a power issue (voltage too high/low, etc.) or a problem with your unit's transformer. See what Outlaw can offer and let us know what amp you end up with.

Yeah, going to work through Outlaw support to get a replacement unit and see how that works out.

I seriously doubt that it's a voltage issue as my Panamax Max 1000's voltage meter is reading solid green and none of the other amps in my system are exhibiting the same issue, but I could be wrong.

Well the Outlaw support guys (thanks Edward) have shown why their support is highly talked about in the community.

They are sending me out a new unit. Now I just need to wait for the return ship label to send the amp I have back to them. Ought to be fun making that walk to the Fedex depot, hehe...not.

Too bad that to do an A/B amp right you have to do it heavy.

Just got the "invoice" for the new amp.

What's really cool about all this is that they didn't charge me shipping either way.

That's what I call good service.

Now I just hope that the new amp doesn't have the same issue.

Got the new amp on Monday. I let it equalize temperature/humidity for half a day as it was sitting in Fed Ex truck in cold & wet Beaverton area for most of the day.

Was well packed just like the previous amp.

Unfortunately, just like the previous amp the transformers are humming noticeably. I do notice that it gets better or worse depending on what else in the HT is on, but it never goes away and is always loud enough to be heard from my sitting position.

This isn't one of those "have to put ear up to the amp to hear it" kind of hums.

I guess the big question is if it's worth having an electrician come out and run a couple of dedicated circuits for the home theater. I'd be pretty annoyed if this didn't resolve the humming issue entirely.

So I'm left with choosing the B&K 200.7 which doesn't make any noise, but perhaps isn't as rock solid of a design and puts out more heat or choosing the Outlaw 7700 that is a heavier design but has issues with humming transformers.

And perhaps I should get dedicated circuits run to the HT anyhow, but it's an expense that I didn't want to deal with right now.

Question still remains whether or not that would resolve the issue.

Any thoughts?

Ordinarily, I'd be embarrassed to admit how many electronic devices I have sharing a single circuit. However, since it may help you, my 7500 is absolutely quiet and it's sharing a single 15A circuit with a LOT of equipment in two rooms.

I'd have an electrician look at the circuit or do some DIY testing if you're confident you won't kill yourself. Determine if you have a good ground. Check the polarity of the outlet. Check for high enough (or too high) voltage. Some equipment is more sensitive to voltage irregularities, miswire conditions, etc.

A simple voltage meter may tell you a lot.

- Jason

How do you determine if you have a good ground? If I had a bad ground wouldn't my UPS note this as a ground fault?

How do you check polarity of the outlets?

Also according to the voltage display on my Panamax Max 1000+ line conditioner wattage is just under 120.

This whole thing kind of makes me think that they had to compromise on the quality of the transformers they used in the 7700 to keep the build cost down. Shows why a lot of amp companies use one very well shielded transformer instead of two less shielded ones. Also shows why Lexicon builds power conditioning circuits right into their amps and why they are so expensive.

Unfortunately, there is no noticeable performance difference between the B&K and the Outlaw, in which case I'm leaning towards returning the Outlaw and keeping the B&K.

Since the B&K does not have this issue.