FWIW.  I was curious if this unit had the option to bypass the built in preamps, like some other interfaces do.  The answer is yes, if you use the 1/4" TRS input, confirmed by MOTU support.  If you use the XLR jack input the internal preamps are used. If you use the 1/4" TRS input, it will accept Line level and bypasses the preamps.
 
 
 
 

To bypass the preamps of the 896/896HD, simply toggle the input level switch on any given preamp to "Fixed." This setting also provides slightly more attenuation than the LINE setting, allowing levels of up to +18dBu.