What sort of power transformer is this?

[mike_mccue]

I had to pull open a a/d/a converter box today to get at a fuse.

I was curious about the power transformer I found inside:

http://www.harmoniccycle.com/hc/images/sound/MOTU896HD/MOTU896HD_powerTrans.jpg

It's apparently a type of toroidal transformer but rather than being shaped like a circular donut it's more oblong and the core is not fully encased. Maybe it's not a Toroidal design at all?

What are these designs called? Are they as effective as the more typical Toroidal design at keeping physical hum at a minimum?

thanks,
mike

[Alex/Tubewonder]

That's an R-core. It's also used by some japanese manufacturers in high end audio output transformers (http://www.icl.co.jp/audio/english/RX40.htm).

R-core technobabble from manufacturer (http://www.kitamura-kiden.co.jp/english/products_e.html)

[mike_mccue]

Thank you very much.

I'll enjoy reading that websites info.

best regards,
mike