How can I improve my electric power situation.

While not a solution to your problem, I'd get a 'Kill-A-Watt' power meter.
This will give you power line voltage, current draw, power factor, VA / Watts and total power drawn by system while plugged in...with an hour meter.

These things are very cheap. like 25$ or so.

At least you will be able to satisfy yourself that you are not dragging the line down. Also, in an apartment, you are not likely to be able to crank it to the point of putting a dent in what power you CAN get.

Use premium extension cords. 12/3 would be where I started. The cheesy 14/3 stuff won't cut it.

I HAVE and use the PSAudio Soloist outlet...had an electrician install it. Good stuff, but I don't know how that helps you.

Thanks for your input. I am going to check those options out, especially the Signal Cable power cord. I also noticed, or did not notice, any improvement in my system after I got the Shunyata unit (6 years ago). What advantage would the PS Audio Duet have over the Shunyata 6? My system can sound rough, or edgy, but I think it is my amp. And I need some additional room treatment. I appreciate your thoughts and ideas. Gives me some direction.

The Soloist outlet requires a doublewide box....like one used for 4 outlets, so once installed you may have to LEAVE it? Maybe uninstall leave the box, put a pair of regular outlets back and take the Soloist with you.

Any way to borrow / 30 day test of another conditioner? My amps have almost never liked them but the low level stuff....CD player and preamp have seemed to benefit. Even if you have to temporarily run a 2nd cord, try the amp as straight into the wall as possible while the remainder goes to whatever conditioner you have under test.

From the FWIW department...I use Panamax. The one I have is an older 5510 which includes a 400va isolation transformer. All lo level electronics goes to this. The TV to another conditioner outlet, without iso and the amp and sub thru their OWN circuit and the Soloist. This thing set me back a grand about 8 or 10 years ago.

Does the stereo sound better at any special time of day? Like late when people start turning stuff off? Or real early Sunday morning while having some quiet time or at Church? That would tell me you need cleaner power.

Late at night and early a.m. Is best. But this is when it's very quiet, no traffic, or drunk neighbors. Sometimes, I feel disconnected from the music and feel like I can take it or leave it. May or may not be power related. I actually think it's the amp, but I do want to get the electric side of the equation in order. Signal cable power cord. My hardware store has those?

signalcable.com