Does anyone happen to know this answer? It's the 1st generation zapco dsp6-sl with symbilink connections. I cant honestly find a Credible source stating it can handle up to 16v balanced input. The gain sensitivity on the dpn software goes from 10 down because the zapco dc reference amps handle 10v for there input voltage. This is important for me to know so I need to figure out how I run my slb-u to get maximum input voltage for lower gain settings and less stress on amps.