You pretty much hit the nail on the head. A lot of stereo preamps these days have a "video" input that you can use for this purpose, but any line-level input will work and you're right that the preamp will need at least two inputs(or one input and a tape loop) for this to work. And yes, the stereo preamp will be the only thing running into the Stratos(the whole point of this is to have only high-quality stereo components handling the signal for 2-channel listening)
The only limitation with this(if the preamp doesn't have an HT pass-through feature) is that when you set the volume levels for all the speakers with the A/V receiver you'll need to have one reference point on the stereo preamp(say halfway) so when you switch to surround everything remains in balance. Some stereo preamps(see below) feature an HT pass-through(generally assigned to one of the line-level inputs) which essentially takes the stereo preamp's volume control out of the circuit allowing the A/V receiver or pre/pro total control over the volume(i.e. no need to set a reference level on the stereo preamp--it just passes the signal through from the receiver to the amp, hence the name HT pass-through). If you have a wife/kids/roommates that also use your system the HT pass-through is nice to have, otherwise it's just a convenience thing(although you'll have lots more choices if you don't need the HT pass-through feature).
Some manufacturers that offer an HT pass-through: ARC, BAT, Sonic Frontiers, Rogue, Conrad-Johnson, VAC, McCormack(RLD-1), Proceed/Levinson, Adcom(GFP-750), and a few others I can't think of right now.
With this type of setup you're likely to save some money, get better stereo sound, have better upgrade flexibility, and have less $$$ at risk as surround formats evolve. If you care mostly about 2-channel and don't necessarily need state-of-the-art home theater performance I think this is an optimal setup. Best of luck.
Tim
The only limitation with this(if the preamp doesn't have an HT pass-through feature) is that when you set the volume levels for all the speakers with the A/V receiver you'll need to have one reference point on the stereo preamp(say halfway) so when you switch to surround everything remains in balance. Some stereo preamps(see below) feature an HT pass-through(generally assigned to one of the line-level inputs) which essentially takes the stereo preamp's volume control out of the circuit allowing the A/V receiver or pre/pro total control over the volume(i.e. no need to set a reference level on the stereo preamp--it just passes the signal through from the receiver to the amp, hence the name HT pass-through). If you have a wife/kids/roommates that also use your system the HT pass-through is nice to have, otherwise it's just a convenience thing(although you'll have lots more choices if you don't need the HT pass-through feature).
Some manufacturers that offer an HT pass-through: ARC, BAT, Sonic Frontiers, Rogue, Conrad-Johnson, VAC, McCormack(RLD-1), Proceed/Levinson, Adcom(GFP-750), and a few others I can't think of right now.
With this type of setup you're likely to save some money, get better stereo sound, have better upgrade flexibility, and have less $$$ at risk as surround formats evolve. If you care mostly about 2-channel and don't necessarily need state-of-the-art home theater performance I think this is an optimal setup. Best of luck.
Tim