Equipment setup..does & donts

The best way, of course, is to set-up the rig in another room, as this not only obviates any effects within the soundfield, but also isolates the gear from any airborne or floorborne vibrations. What percent of the people have a setup like this? Very few, I suspect.

I keep my equipment on multiple low stands.

I agree with Viridian, that would be wonderful. The best I could do is place mine at the opposite end of the room, about 25 feet away and built into the wall.

Great support for the equipment and far enough away from the speakers to not bounce the preamp, phono stage, CD and turntable. The amps must be by the speakers to keep the speaker run short.

If I had the space, I would have my room just as it is, but the amps would be behind the back wall (where speakers are) and cable run through a small opening.

Veridian, so long as any room is oxygenated and/or directly or indirectly anchored to planet earth there is no such thing as isolating gear from vibrations but yes being in another room can certainly help minimize some (not all) of the sonic harm induced by improperly managed air-borne and floor-borne vibrations.

Moreover, internally-generated vibrations (eg motors, power supplies, etc.) will continue to induce the exact same sonic harm regardless of what room they are in.

Since air-borne and internally-generated vibrations can be addressed the exact same way, it makes sense (to me anyway) to properly deal with the vibrations and if I do then it won't matter which room the components are in and I won't have to worry about 30 or 40 ft speaker cable runs either.

As for the height of the components affecting the soundstage, most likely it depends more on how far out into the room the speakers are placed. If the speakers are only a few feet from the back wall then raised equipment may (or may not) compromise the beauty of a full soundstage. But in many cases if one's speakers are this close to the back wall they probably have bigger issues to deal with anyway.

If the speakers are say 6 ft or more out from the back wall I wouldn't worry much about it.

-IMO