Reimyo DAP-777: Output Impedance

I am using a Reimyo DAP-777 DAC. I would like to know the output impedance of the DAC at the RCA as well as the Balanced outputs. I need this info because I want to use a passive preamp in my setup. There is no info about this on the Reimyo website. Can anybody throw some light on this.

I saw in a German review where they listed the output impedance at 146 ohms. I don't recall it specifying RCA
or balanced.
I dont know why Reimyo has not specified this figure in their specs. I am not even getting it from the internet.
I thought it odd also. I just happened to stumble across it by accident.
Thanks a lot Con2785. That document certainly looks assuring.