ES-9 analogue input specs, frequency response, HPF corner & amplitude linearity

[mahyar]

Hello,
I'm putting together a measurement setup using the ES-9 and hit a few gaps in the manual/product page:
1. Frequency response, DC-coupled mode: Since there's no HPF on this path, is there any data on how flat the response is down toward DC? Just trying to understand the low-end behavior of the DC-coupled inputs.
2. HPF on the AC-coupled main outs: Is there a corner frequency (-3dB point) for this filter?
3. Amplitude linearity: Any characterization data on how closely the DC-coupled I/O tracks an ideal transfer function across the full ±10V range?
Thanks very much in advance.