A software fix from Oppo is certainly possible since the volume control within the DAC has a resolution of (1/64 = 0.015625 dB) but they give us a coarser version of it to fit within the 0-100 volume scale. Otherwise it'd take forever pressing the volume buttons to effect a meaningful volume. I think this can be easily done as an option within the audio setup menu.
OTOH, i can't believe audiophile XLR attenuators aren't available. The Rothwell types seem to be the favorite for high-end systems according to the reviews i've seen which dubbed them as being neutral. Ideally you need a 12dB attenuation pad to fit the requirements of your power-amp, but their 10dB will do. Have you asked SimAudio for what they would recommend?
I agree with your propsed software solution. Unfortunately, OPPO is refusing to acknowledge that 105 is being promoted as a Player and Preamp. Therefore, OPPO does not feel that 105 output need to support the industry standards for power amp input sensitivity which is 1 Vrms instead of 2Vrms (RCA) and 4.2Vrms (XLR). I contacted OPPO to present the issue with 105 output for its role as a Preamp and to encourage them to provide us with a software solution - see email below.
I have not contacted SimAudio yet because volume control is a function of a Preamp, and this issue need to be addressed by OPPO as long as 105 is being promoted for Player and Preamp roles.
OPPO suggest that I use an -12db Inline XLR Attnuator in between 105 and power amp while admitting that they never tested this solution.
OPPO further argued that they have not heard about volume control problems with 105 reviewers and customers, and I did point out to OPPO that some of the 105 owners have begun posting volume control problems on this AVS Forum.
I encourage 105 owners who have the similar problems to let OPPO know and post your experience with 105 volumne control as a Preamp. We need to work together to change OPPO's position to address this issue.
Until then, the following represents my current status on OPPO's response on this topic:
On 2012-12-12, at 3:40 PM, OPPO Service wrote:
We disagree with your assertions and have not had any reviewers, customers, beta testers, or external advisers show an apprehension towards the player outputting 2Vrms for single ended analog outputs and 4.0Vrms through XLR.
Unfortunately we do not have any recommendation as to which XLR attenuator you should use, as we have not done any testing with these devices as we have not had a scenario where we needed to attenuate the XLR outputs on our players when connected direct to an amplifier or pre-amplifier.
Thanks in advance for your care and solution, soon.
Edited by edwardkim - 12/13/12 at 2:33pm