I propose to buy a model to work between a good stereo amplifier for loudspeakers and electrostatic headphones, version of the model 2012, a well-known author from Germany. All works without problems. The 1200v offset can be changed if desired.
price with delivery.

P.S. I also posted it on Ebay, it has a better reputation there. no problems with shipment, there are many positive reviews on ebau from buyers from many countries around the world.