[morzh]

This is the Push-Pull transformer. You need a Single-Ended (SE) transformer.

125CSE by Hammond is the one you might want. But it is expensive.

Your connections will be primary - only one way and the secondary - BLK to ORG/GRN for 4/8 Ohm

http://www.ebay.com/itm/240012-Tube-Audi...SwRUhY9jyc
http://www.ebay.com/itm/tested-tube-amp-...SwlndZCoDF
(these two do not say if it is P-P or SE type, nor do I think they have documentation with them - you could ask)

http://www.ebay.com/itm/OT10SE-USA-Singl...xy2E1SEY30

http://www.ebay.com/itm/OT8SE-Single-End...SwgNRV8Oov
(my favorite - you have to see if the size fits).