[sdiy] Transformer types (specifically for a sci pro-one)

[Julian]

I need to get a transformer for the pro one im gradually working on, but I cant claim to be that familiar with the pros and cons of
various types.

First up, I should just confirm ive got it right in thinking that the pro one has a dual primary winding, running one for 115v and
both in series for 230v, and then dual secondary (18v each) in series, with a centre tap to ground?

On the schematics ( http://port23.co.uk/pro1-schematics-a.gif ) I also see a couple of points which in don't yet understand (I don't
have the pcb in front of me right now, so that may have helped)

The points are the connections 5 (keyed), 2 NC marked just to the right of the secondary windings?

But the main question:

Different types of transformer.  In this application should I be concerned as to the design type, or just grab a chassis mount or
encapsulated device of a suitable VA? (ahh, and what sort of VA capacity should I even go for?)

Like I said, I don't know a great deal about transformers.

And I cant just look to see the original, as, well, it isnt there any more (along with, I should add, most of the rest of the
pro-one....)


Cheers, Julian