Will Stax Low Bias Phones Run Off The Koss E9 Energizer/Transformer?

[edstrelow]

The title says it all. I just picked up an old Koss Esp9 phone on ebay, so I dusted off my E9 box and wondered if the Stax phones would run with it? Some of the Koss phones will run off Stax amps, etc, so why not the reverse?

 

[Duggeh]

The pin out configuration on the /E.9 is different to the Stax plug layout, you would have to rewire the energiser or the headphones.

 

[spritzer]

None of the Koss phones will run unmodified on Stax amps. The bias is around 450v or higher (950) but they all use different plugs or very different circuits. You can do it by transplanting the PCB's from inside the ESP9 and connect the output from them to a 6 pin plug but you will burn up the Stax phone due to the higher bias. The Pro phones will work though. This has been on the my to-do list of a few months but I just don't have the time to spare. The Stax phones will sound very odd because of the strange Koss diving circuit but it would be a fun mod.