transformer iso box question

http://www.fivefish.net/diy/IsoBox/default.htm with this would anyone be willing to give me an idea of transformers I could use price an ranges and some schematic or simple drawing to hook this up?

What impedances are you wanting to interface? Modern bridging types? Get some 10k:10k types then.

What country are you in? Stick with good quality; Lundahl, Sowter, Jensen, Cinemag, Haufe, etc. Maybe Beyer and Neutrik for generally lower level stuff.

Schematic should be input to primary, output from secondary. If source is always unbalanced and requires ground, then tie the low end of the primary to ground via pin1 on the output. I'd add a switch to lift the ground on the output in case it helps for ground loops at some point. Tie the case to the output's pin1 too.

I've tried both 600:600 and 10K:10K, and I am partial to the sixes.  I have them in all sorts of studios, conference rooms, home theaters, etc.  Looks like the box in question uses Edcor iron, but there are options from $20 to $2,000 each.  Check the white market for members selling new transformers, black for used.
Mike

What impedances are you wanting to interface? Modern bridging types?

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I have no idea I'm just tryin to get a lower noise floor out of a allen an heath sr416 going in via trs to a computer interface I figured star grounding and adding a iso transformer would do the trick but I have never really messed with transformers before, but it looks really simple so thought I'd try it 

so from a few other posts i guess im looking for a 600 ohm 1 to 1 transformer

What does the noise floor sound like?  Hiss, zizz, or buzz?  It is better to deal with zizz and buzz with proper grounding and cabling, which should eliminate it.  Hiss is normal, unless it is really loud.
And yes, 600:600 like this.  I think this is whats in the box above.
Mike

it's hiss mostly it's normal I know for any tl072 circuit but I figured it can't hurt to try and lower the level and its spomething new I dont know Transformers and I just want to learn how to get better at this stuff I enjoy tearing stuff apart finding how they work and improving them mixers preamps etc it's fun and rewarding