Solid state - How wide can 3D image go

I agree that the room and placement is important, but digital equipment can definitely affect your soundstage. A key technical feature of a good streamer is low jitter, with negative results being a poorly defined or smeared image. The DAC you are using certainly figures into the equation as well. Can you provide some details on what you using for streaming and DAC? 

what I can say is that using the Philips CD player (has a CD or Transport) I get a huge sound stage. If I then change to a Sony CDP-997 (has a CD or transport) it does not give me that big of a sound stage.

I suspect you have identified your problem. The Sony, which appears to be vintage(?), has a poor or out of spec clocking system, and is creating a lot of jitter in the signal sent to the DAC. I plugged in my old Nakamichi CD player a few years ago to see how it sounded, unlistenable compared to the streamer I had in place. There could of course be other factors influencing the digital output of the Sony, but just letting you know what I have found experimenting with various digital sources running to the same DAC. 

In the end I eliminated both my CD players altogether. Ripped all my CD's to a network drive and used a Sonos Connect for streaming them and online content. The reason I know how much difference a streamer can make is that as an experiment this winter I put together a Raspberry Pi box with an Allo DigiOne streamer board in it to see how it compared to the Connect which is known to be a bit jittery. Immediately noticeable improvement, two different streamers, same DAC. In your case, two CD players, same DAC, noticeably different. Honestly, I would just chuck the Sony as I do not think there is a way to fix the issue.

Got it, sorry I was missing the point. What are the other components of your system? 

It sounds like you have the cabling and isolation well thought out. I have considered using the relatively low cost TP Links, do you have any feedback on them? Did they make a difference?

I am sure there are those that would differ, but while I think decent cabling and isolation make a difference, it is not going to provide the drastic improvements that good components will offer. Updating my preamp made a huge change and I have upgraded my power amplifier this year, improving imaging yet again. But preamp, that was a big one. Along with clean digital components, I continue my search to improve there.