HELP: Speaker Level settings shut off when I power down Sony DVP-NC650V

I've been messing around with SACD via 5.1 analog outputs for years. I've had a Sony DVP-NC80V for at least decase which sounds nice over the 5.1 outputs, once you set the speakers correctly; unfortunately, although it is a 5-disc player, it does not permit multi-disc shuffle play. I also have an Oppo 103, with 5.1 analog outs. On the latter, I have to go into the Oppo's settings increase the sub level to +10dB and lower the remaining five speakers by -5dB, and then raise the receiver volume on the MCH input by +5dB and voila: perfection.

So recently I came across a Sony DVP-NC650V, which is very similar to the NC80V except that it DOES allow multi-disc shuffle play. What's more, in the speaker settings, you can increase the sub volume by +10dB, whereas the old 80v only allowed you to raise the sub by +5dB. Following the success I had with my Oppo, I've also lowered the remaining speakers by -5dB; the results are identical to those on the Oppo, which match the settings for SACD over HDMI, so I'm sure I've hit the sweet spot. BUT . . . when I turn off the machine, the lowered volume on the speaker settings gets shut off: I'm back, basically, to 0dB on the five speakers, +10dB on the sub, and +5dB on the receiver's input setting. Is there some secret to making sure this machine doesn't shut off the lowered speaker levels on the 5 speakers? The player sounds OK with just the increased sub volume but it's clear that I'm shy some LFE volume. So I'd like to figure out why the player keeps overriding the decreased speaker volume settings when I turn it off. Thanks!