Sanders 10c/d + Magtech + tube preamp

I have a setup that is similar to what you are suggesting.
A cary slp-05 tube pre into a innersound esl 300 (sanders esl 300) that powers a pair of magnepan 3.7 speakers augmented by a pair of velodyne dd8 subs. It is a very nice sounding setup and you can tailor the sound of the system to your liking by rolling various nos and new 6sn7 tubes in the cary tube pre. The cary tube pre and sanders amp are a great match through both the rca and balanced connections.

One of the most effective attribuites of Rogers design (and why his stats perform so incredibly well) is the external crossover. You really don't want your amps "seeing" a crossover. You want it "seeing" the drivers.

One of the most effective attribuites of Rogers design (and why his stats perform so incredibly well) is the external crossover. You really don't want your amps "seeing" a crossover. You want it "seeing" the drivers.

Cerrot, i really don't understand this
The x-overs is external - ok. so, you can tweak it & control it much better compared to it being inside the speaker. But still your amp will drive the external x-over & the external x-over will be connected to the speaker (with short leads, very often). Your amp will still see the x-over & not the driver. I'm not sure i understand how an external x-over will make the amp "see" the driver?? can you explain? thanks.

Not at all, Bombaywalla. My amps are between my crossover and my speakers so my amp sees my speaker, not my crossover. That is the idea. Amp does not see the crossover which is an impedience nightmare.

Preamp to crossover to amp to speaker as opposed to amp to to a box of capacitors and wires inside your speaker.

Thanks, Cerrot. got it!
looks like Roger uses active x-overs that use a line level signal from the preamp. I thought, for some reason, that Roger was using passive x-overs. not the case.