STAX SR-M323A balanced input mod

[Marin M]

Hello

I would appreciate if somebody could help me. 

I need to install XLR input sockets into my SR-M323A. 

I am fine with soldering and will have no problem installing it physically,  the only trouble is  that I do not understand circuits well.  I am really determined though

On the PCB input section I noticed an empty space for a resistor and a capacitor for each channel respectively .

Has anyone done this mod? 

Thanks

Martin

[Marin M]

And here are some photos of the PCB.

http://s1378.photobucket.com/user/Mmartin33520/media/IMG_20170528_194002_zpsqheoalkb.jpg.html?sort=3&o=2

R2 and C2 on both channels are empty as well as the third hole just next to the R and L letter on the PCB. Would it be for a negative part of the balanced input signal?

What kinds and values of the caps and resistors should be soldered in there? 

Would it be possible to have a switch for a single ended or balanced mode? If so would it be complicated or difficult to do?

My DAC can work in pre-amp mode so the stock pot is not essential, unless it could be modified for the purpose.  

Maybe at some point I can find a 4 gang one, but for now, I can bypass it completely.

Please let me know if I have omitted any relevant info.

 

many thanks

regards

Martin