Outputs: 4 volts Oppo 105 vs 9 volts output Outlaw 990. This explains the gain difference as well as the added head room. This also explains why many feel you need a preamp in front of the 105. In theory 2 volt output can drive most amplifiers to full output. In reality this seldom works you lose base impact and dynamic range. To test this theory I put a 4 channel class A active crossover between the BDP-105 7.1 output(I use 5.1)and the 7.1 input (again I use 5.1 only)of the Outlaw input. (The active crossover will swing 14 volts). The surrounds are set to small in Outlaw. The activate crossover does 3 fronts and sub. In this setup when I use 7.1 with LPCM192 the dynamics are restored and using the 105 as a preamp would work. It still will not fix the bitstream issue to the 990 but the gain and dynamics are back.
I got this idea from theta digital. All of their stand alone D/A