I have a few questions and comments about this...
Did you try another outlet (without the panamax)?
Is the unit in close proximity to anything else?

If you are serious about the sound, a dedicated circuit is a GREAT investment. I put one in myself before I got my units, so I do not know what they sound like without it. I do not use a power conditioner, just an inexpensive surge protector (read power strip). I had thoughts of buying one before I heard the system, but it is dead silent, so I didn't want to mess that up.

The reason that I asked the first question is because there is one circuit (room) in my house that buzzes any equipment I plug in (guitar amp, stereo). I suspect a bad ground, but have not fully investigated. This is isolated only to that room.

Also, your panamax should not report a ground fault for a faulty ground.

The amp is on the same circuit as several lights, and all the HT stuff.

It makes a noticeable hum regardless of where I plug it in. Currently have it plugged in through 20' extension cord to a plug near to the kitchen, unfortunately there is no well isolated circuit within reach of the amp.

It's just disappointing really. I've been wanting the Outlaw amp for quite a while and now that I've gotten it and a replacement, both with humming transformers where a "brick and mortar" amp doesn't.

Once again the Outlaw support team continues to shine.

They are sending me out a DC power filter to help troubleshoot the issue.

Also have an electrician coming out on Monday to give me a quote on adding a couple of discrete circuits for the HT.

For some reason, whether rational or irrational, I'm willing to work a bit to keep the Outlaw amp.

I had the same issue with my 7500. I never could get it fixed. I now live in a different apartment and it no longer makes that hum

I had the transformer hum problem with an Aragon 8008X3 amp. The diagnosis: DC coming in over the cable connection. A Jensen isolation transformer provided the fix.
If you haven't tried it, disconnect all inputs to the amp and see if the hum persists.

I'm using balanced cables to go between the prepro and the amp.

Doesn't this theoretically protect me from power issues coming from the inputs?

We'll see what happens when I get the DC filter they are sending me.

Blogging ITGuy,
Balanced XLR connectors have three pins: signal+, signal- and shield. The shield is probably a ground from your preamp which is connected to the ground from everything connected to the preamp. Simple test: turn off the amp, disconnect the XLR's, turn on the amp and see if the transformer is quiet.

Interesting...so with no inputs/outputs plugged into the Outlaw it's more quiet but still giving out an audible hum...until I turn on the 360 which is on the same power circuit and then it starts humming quite a bit more loudly.

But it never quiets down to where you can't hear it at listening position when the room is quiet...which quite frankly is not what I expect from a a piece at this price point.

Will have to wait and see what difference, if any, the DC filter makes.

The XLR should help against ground loops, but this is different than DC on AC. Since electric companies don't worry about the quality of the electricity you can have this problem. It is also less obvious since most electronics like computers, etc... use a switching power supply that doesn't care about that issue.

Analog power supplies can have an issue with it though. I've seen the scope view of DC spikes on a AC power line, and I've heard about it being fixed by a basic capacitor filter box.

Had an electrician over today to give me quote on getting dedicated circuits run.

He quoted me $350 for running two separately grounded 20 amp circuits from the panel to the home theater.

Seems like a decent price.

Probably a good idea to do it regardless of which amp I choose.