A/B/Y questions GEO 'U.H.F.S.'

[petemoore]

http://www.geofex.com/
  I do see a buffer input, split to two modest gain opamps which drive A/B outputs through transformers.
  The switching has me confused.
  Which two 'triangles of switch lugs' switch at the same time? [1 'triangle  = 3 lugs = 1/2 of a DPDT].
  there are two DPDT's shown, what do they do ?
  It would seem possible to build something which drives two amps but breaks the ground connection without any switching and LED indicators?..it seems I could 'de-fancy' the build, eliminate switches and simply unplug to bypass the unit entirely when using 1 amp?
 

[R.G.]

The dotted line between the switch bars are a common way of showing linked action on schematics. In this case, the two lower half-switches are linked, and the upper two are linked.

The lower DPDT sends signal to one or the other output , but not both, giving the A or B action.

The upper DPDT links signal to both of them at the same time, giving the "both" action.

It is indeed possible to do a splitter to two amps with the transformer isolation. That's here:
http://www.geofex.com/FX_images/splitter.gif