OK, time for a compromise :(
I am going to settle for 2 x 8 - 1 analouge mix downs for the 2 channel output.
I'm going to try using a THAT1606 OPAMP differential line driver for the XLR outputs
some specs that sold me where
"Balanced, transformer-like floating output
Stable driving long cables and capacitive loads
High output: 18Vrms into 600Ω
Low noise: -101 dBu
Low distortion: 0.0007% @ 1kHz"
At some point mixer has to go Analouge for the outputs so I thought It may as well be here.
I have to use +/-15v ( approx ) clean power supply for the THAT1606 so I went for the new
I can use 2 x DACS for a repat of the 8 inputs and balance by incrase / decrease the copied channel.
BUT, how can I make a master volume control ? or a headphone monitor ?
say2 x LM1972 digatally controlled attenuators or 4 channel PGA4311. but there both single ended !! ahhhh !!!! audio needs to stay differential all the way out !!! I'll work that one out later !!
well, i ordered the 2 x THAT1606 and power supply. I have no idea what resistors to use to devide the 8 outputs ( 16 differential resistors per channel output ) down to normal level. I guess I'm dividing equally by 8 so they should all be the same but what value resistor to use?
DAC outputs are;