What I heard is that some of the Tango staff were involved in the design. Who knows whether it is true or not but it came from a friend who is obsessed with transformer quality...
High-Quality Stax Headphone Adapter - Page 2
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I never make BOM's for anything but what parts to leave out depends on what version of the board you have and how you want to use it. The 1.3 version added 10mA led driver which you can leave out if you are using the neon bulb. It's the cap, bridge and 2k2 resistor. If you aren't using the neon bulb either then the 150K resistor can be left out as well. If you are just going to use the Pro output then all the VD spots can be left empty and one of the 10nf/630V caps isn't needed
As for the parts, all the caps were Wima MKS4 and all resistors were 1/2W or small 1W units. Voltage rating is the main criteria here. 100V zeners are 1W or bigger and the main diodes are 1N4007. Remember to jumper the fuse connector if you aren't going to use it.