The unit for sale is on the left. Two par-metal cases... one for the S22 PSU and the other for the three channels of B22 goodness. There is zero hum. They are connected via umbilical with speak-on connectors. Pot is Alps27. Gain is 8x. I've been using this setup with my Senn HD650 and I still have yet to find it's match. Need to fund some new projects now. Please email for faster response. jasonwang99 at yahoo dot com.
$900 Price includes shipping (US) and paypal fees.