Firmware 1.70 is out:
2) When playing CDs or DVDs over HDMI or SPDIF and jumping or transitioning audio tracks, certain players exhibit a momentary audio stutter just as the track begins playing. Since not every player causes this problem, firmware rev 1.70 adds an ‘Auto Mute’ time that can be set manually to mask this artefact as required. This feature is found under SETTINGS>SYSTEM>VOLUME SETTINGS. Users should start at 50ms and increase the time until the stutter is no longer heard as one jumps or transitions tracks. Typically, a setting of 350ms will achieve the desired result.
I'm puzzled.
Still using 1.60 firmware, because I wanted to be sure I knew how things were working with their first attempt at fixing this, so that I could evaluate what if any change would occur after upgrading to 1.70 and possibly tweaking this new "Auto Mute" time value. From its description when I see the word "mute" I think "absence of sound". So how can some brief mute period do anything more than possibly mask out the stutter artifact which occurs when the audio begins playing? How does it not therefore also genuinely eliminate that much audio from the start of the track, while therefore at the same time hiding the audible stutter which occurs within that small time slice? Don't we want to hear all of the audio on the track? Why give up another 50-350ms of audio, just because there's an artifact within that brief time which is tied to the A16 and which is what really needs "fixing and eliminating", not hiding by muting?
My setup provides the ability to do a very easy A/B comparison of CD playback:
(a) Oppo BDP-103 -> LPCM via HDMI2-out -> HDMI1-in of A16 -> optical out -> optical in of external DAC -> XLR out to Stax amp/headphone
(b) Oppo BDP-103 -> 48K LPCM via coaxial out -> coaxial in of external DAC -> XLR out to Stax amp/headphone
So (a) is CD via HDMI from BDP-103/LPCM into A16 and then optical into the DAC, and (b) is CD via SPDIF directly into DAC. In both cases the DAC feeds XLR output to the Stax amp/headphone. Both setups involve the identical CD player. All I have to do is hit the INPUT button on the DAC to choose either (a) optical input coming from the A16, or (b) SPDIF input coming directly from the BDP-103.
Again still using 1.60 firmware when I navigate CD tracks using (a) there is of course the now well described tiny "stutter" as the audio begins. There is actually already a brief mute period before that (perhaps 1/2 second?) and then sound appears, which begins with that "stutter". In contrast, when I navigate CD tracks using (b) it plays perfectly! 100% of the track is delivered, and the instant-sound presented at the beginning of the track does not exhibit any stutter.
Does this not clearly imply that there's something not right with how the A16 is handling PCM delivered via HDMI from the BDP-103 because there is this brief mute + "stutter" artifact? In contrast the same PCM delivered via SPDIF directly to the DAC/amp/headphone has no 1/2 second mute, and no follow-on audio stutter artifact needing "blanking" (as a "fix") in order to prevent the stutter from being audible?
What am I missing? Why does Smyth feel that providing a secondary variable-length "mute" to prevent the stutter from being heard, on top of the existing 1/2 sec mute that they reduced the 10-second mute down to with 1.60, that this is a "solution" to the problem? Why does the DAC have zero issue handling the PCM output of the BDP-103 via SPDIF such that 100% of the track audio is delivered with zero stutter, while the A16 has a problem accepting PCM input via HDMI which results in our losing about the first second of every track or following any jump?
I'm clearly not appreciating what they're doing here in 1.70, other than adding a second variable mute period to audibly erase the stutter, thus resulting in an even longer period of loss of track audio than just 1/2 sec.
Didn't their original thought in the README for 1.60 indicate that the problem is tied to the use of the decoder for PCM, when it actually wasn't required and that bypassing it entirely would solve the problem completely? I wonder why they didn't just do this in 1.70?
In other words I think I disagree that the issue stems from the CD player, and is something that's just going to be there if you use that player, no matter HDMI or SPDIF out, and therefore it's not "fixable" in the A16 but requires this muting to just make it inaudible. It's clear from my own BDP-103 test that it's NOT coming from the player, but rather from the processing in the A16 and which doesn't occur if you use the very same CD player and simply bypass the A16.
I think they need to fix something in the A16 to bypass the "problem processing".