Do I need BOTH amp and pre to be sonic holography?

Sonic holography is patented, there is a patented circuit which intentionally manipulates phase to couple the left channel to the left ear and the right channel to the right ear. Sound stage is wonderful on tubes but a totally different thing than Sonic Holography. Do a patent search and you will find Robert H. Carver holds the patent

Sorry, Robert W Carver.

There is someone on ebay selling C-9 upgrade kits, also sometimes C-9's with the upgrade installed.

This unit below seems to me much the same thing, but modern implementation, seems you adjust the settings with a computer via USB..

http://www.ambiophonics.org/Ambio4YouDatasheet.html

Phase Linear 4000, was the first time Carver used that circuit. While it was quite interesting when compared to "Mid Fi", it doesn't hold a candle to a "high end" sound stage, and not only that; but the parts were cheap.

The delay that Carver's holography unit developed was not just to somewhat counteract the signal from the opposite speaker, it also accounted for diffraction caused by the listener's head. When sound from the left speaker hits the listener's head, the head itself causes the soundwave to travel around the head from the left side to the rigt side, again on a delayed basis. The Carver circuit compensates for this as someone described above (delayed, inverse phase signal sent to the right speaker).

I have (somewhere in a closet) a holography generator. It does create, with most recordings, an extremely wide soundstage, with some images sounding like they are completely to the side and quite close to the listener's head. The sound is quite phasey and not entirely realistic (though fascinating).

There are recordings that were made with these compensating signals built into the recording in order to throw images way outside the speaker. Roger Water's "Amused to Death" is an example. A less extreme (more subtle) use can be found on a Nouvelle Vague "Nouvelle Vague" recording (French girl group doing terrific covers on Brit pop/rock). If you want a rough idea of what the Carver circuit can do, get the Roger Water recording.