differntial surround

[Andy Le Blanc]

I've using a couple of extra speakers, wired between the + terminals of a stereo power amp get the rear surround channels for home theater.
It works, you get the diff stereo channels, a basic quad stereo, but it makes balancing the speakers tricky, there's no real control.

So I've been playing with an idea to use a couple simple cathode followers, the same as in bassman, or a marshal to drive a couple matching transformers between them to get the differential channels, which should allow me to better control the balance of the rear channels thru their own amp.

A center and sub channel are simply mono sum, you can simply use resistance mixing to get them, but rear channels are differential.
I believe that I can place and drive two signal transformers in series between the L and R followers, without referencing them to ground, to get rear channel outputs.

will driving two signal transformers in this way get me the differential signals?

It's beginning to look like it could be a fun little build, a small pre amp, using tubes to get front and rear stereo, center and sub outputs.
A bit off topic I know, but an amp is an amp...