Replace Silver interconnect cable , please advice

So your source may not be a good match for your system, but don't start buying new gear yet. First try different placement of gear and sofa. Al pointed out possible bass suck-out; can you move the sofa close to the rear wall and toe-in the speakers?
Concerning weak soundstage, you'll never have a wide soundstage with the entire space between the spkrs filled with furniture. You need some air between the spks, maybe switch that IKEA unit to something vertical or shorter and put the amp on the floor (using good anti-vibration feet).
Also experiment with a blanket over the TV; it's causing reflections.

@Pelo911 : I agree with Lowrider57. Even if i think your speakers is a limitation, you should try to optimize your system before changing anything. An optimization is always a good thing to do because, even if you change your speakers afterward, you'll always keep your optimization! Furniture is a good start. www.hifiracks.co.uk is one of the best gear i heard to date for isolate electronics's vibrations. Try to move your speakers in the room to test acoustic problems.
My recommendation for speakers is always the same : USHER AUDIO. Best speakers for the money, period...

As a good DAC, you can try Mytek DSD DAC. Not expensive, handle HD tracks and very nice and musical. W4S DACII is also a great deal for small money!

Silver can even sound more musical than copper. It depends about the quality of the silver what is used. One thing is a fact that the best quality in silver Always beats the best copper in resolution, speed and drive. I use the Acapella pure silver XLR. This one is very dynamic and has a warm mid freq. I recently bought the brand new Audioquest Wild Blue Yonder with the new xlr plugs. Also this cable is very musical, with a very deep and fast low freq. Cheap silver cables can sound harsh and miss dynamics.

I tested many interconnects on Pass amps. You need an interconnect which can give a very sharp and realistic dimension of instruments and voices. Pass Labs give a deep and wide stage, but does not give the small and direct image you need. You need to understand all the properties of the stuff you own before you can choose an interconnect. Becuase they also have there own properties. For example; MIT and Shunyata make the stage also deep and wide and have the lack of a realistic dimension of instruments and voices. This irritating misstake is often made at shows.