1st setup failed, need advice for B&W N805 amp


Okay, so my current components are failing me. I have a Peachtree Decco and Emotiva UPA-2 (just received this, motive for my post).

I was previously using only the Decco to power the N805's... my source was my PC connected via USB. So the Decco functioned as a DAC/preamp/amp and all was fine... except two things. 1st, although the room is small, I could use a bit more power. 2nd, I noticed the left channel on the Decco was a bit louder than the right. At first I thought it was the speakers, but I tried another set and same thing. It also doesn't have good balance at low volumes.

So I bought the Emotiva UPA-2. Fast forward to today. I setup the UPA-2, turned the power on, and to my disgust - there was a very loud/audible humming which corresponded with the output level on the UPA-2. At first I thought it was my generic monoprice cable causing the problem. But then I tried connecting both my TV and iPod straight to the UPA-2 and... the humming was gone. Could it be possible that UPA-2 doesn't work well with a tube preamp? Either way, I disconnected the thing and I'm back to using the Decco only.

I really need some advice. First, is there anything I should try before giving up on the Decco + UPA-2? And second, if it came down to it, I'd rather keep the Decco and look for a new power amp. I'm trying to keep the price under $500 and used would be okay. I don't need anything crazy, the room is only about 12x12. Any suggestions would be greatly appreciated... thanks
koven
I have been thinking about Blindjim's comments and I think he might be seeing something. I have heard about ground wires sometimes setting up current loops in audio systems that cause audible hum. PS Audio actually makes the ground pin removable on some/all of their power cables to address just this issue. His $0.75 hardware store and/or "move the plug" solutions could be very cost and sound quality effective.
Why why why? To think that a $500 amplifier tacked onto the back of a Decco should be able to do justice to a highly regarded $2,800 stand mounted monitor speaker seems a bit optimistic. In my experience a like priced or higher piece (or pieces) of electronics is what is needed for those wonderful little speakers to really shine. If you look at any Brit mag you can easily see when system recommendations are made that the budget for the source and electronics always exceeds the cost of the speakers.
The idea is simple....whatever you put into the speakers
will be what comes out. The better the source, the better the sound.

NAD....not your best choice.
Maybe try a Cambridge Audio 650 integrated?

I am listening to a 550 currently, and wow this little amp is surprising me. Don't be fooled by the price.
Koven,

I'm with the first posters: don't assume it's how the electronics are. Follow their leads. Leave component changes for last.

On my upgrade path I've had B&W 804S connected to relatively cheap Rotel components and, while the sound wasn't the best the speakers could reproduce, the components didn't have issues like humm.

BTW, I was thinking about a Decco for my brother, so I'm interested in your experience.

Good luck!
Horacio