If you allow me, I can explain to you.
Here we go: plug 4 pin male to 4.4 mm female adapter in 604 frontal 4 pin output and now you can plug a 4.4 mm male to 2 XLR male cable from 4.4 mm female adapter to your XLR amplifier input.
I hope helped.
I would like to see next HPA from Topping: Resistor Ladder Volume Control, true bal input, all kind of phones output, perfect R&L channel match and no preout.
Where are the good valuable components? I only see: futurist design + heavy gear + marketng = EXPENSIVE ILLUSION (all of them intent to deceive). This kind of act=PRISION.