Creating a Large Sound Stage

Pull speakers away from walls.  This is the best audible example I have ever come across that demonstrates this.  Record Day also have a system to pull speakers out call LOTS.
https://youtu.be/mjQ2Wy24wC4?si=ZtApabZ32CSJTJdx

So you want a large soundstage? Get a pair of DCM Time Windows. They measure as well 90° off-axis as direct. I have a pair in use as my main speakers. 

'Tube power supply for the turntable…ya just can’t be careless hoping a SEMIconductor will oblige free passage'……

Older op amps are not good, but the Muses02 should create a large sound stage.

Speaker design and placement...

I've had a pair of Polk l800 SDA designs sitting around in storage for a while (not for sale however). You could put any trash recording on it and it will create soundstage sprawl and envelopment.

Big horns...especially some higher end pro audio designs from guys who know their stuff will tend to do that...the sprawl and envelopment..

Guys who say it is all "recording dependent" will usually have unintelligent boring speakers and goofy rooms.

The amp...well...don't get some stage depth flattener like a unintelligent Bosemcintosh or something else that's gimping your intelligent speaker...and so on...

The dac..well...some tricks can be played here.... Even some "purist" dacs have certain processing "enhancements" built in for such purposes (that you just didn't know of).....and so on.

Hope that helps...

Or finish your undergraduate stereo degree and go to multichannel audio graduate school (like 360 reality,  atmos and so on....) soundstage sprawl and envelopment for days...