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Everything posted by testikoff

  1. Thanks for confirming. Is it fair to say that all the MQA-CD does is carry the original sampling rate of the PCM master + the preferred upsampling filter to be used by the MQA-enabled renderer/DAC?
  2. So is there any truth in Bob Stuart's statements regarding B (i.e. 22...44 kHz or 24...48 kHz out-of-band spectral content) "estimates" in 16-bit MQA-CD audio of recent Warner & Uni Japan releases?..
  3. How about these passages from Bob's post: The Green signal is completely removed by MQA decoders; but it is there so that we can hear more of the music when playback is limited to a 16-bit stream. The coder for B uses an approximation (prediction) + a touch-up signal to make it lossless. The estimates of B1’ and B2’ can be buried within or below the green line (at the choice of the mastering engineer). The next step is to fold this information into a small 48kHz 24-bit PCM file that you can hear wherever you play music today. If we do
  4. Can you debunk his statements regarding out-of-band spectral content of MQA CD audio?
  5. Are you saying that the above mentioned Bob Stuart's posts are entirely false?
  6. Can anyone comment on contents of Bob's recent posts specifically in regard to MQA CDs? http://www.bobtalks.co.uk/2018/09/
  7. Oops, forgot to reset my Audacity setting of 16-bit sample precision to 32-bit float...
  8. What you posted is a spectrogram, not spectrum...
  9. Post the spectrum of your null-test delta signal for comparison.
  10. Shouldn't the spectrum of null-test delta look something like that (well, mine does)?..
  11. The waveform delta of of my loosely aligned analogue capture 1 & 2 excerpts is not great, admittedly... The excerpts spectral delta, however, shows no substantial difference in spectrum within audible range, so regardless of small differences around 400Hz noted by others, they will be extremely hard to discern when the actual track excerpts are played back (not their refined null-test result produced by DiffMaker), IMHO...
  12. Here you go: - Delta closeup (frequency range 20...20000Hz; logarithmic scale):
  13. No, just lined up samples the best I could on time axis (almost impossible to do with all the HF noise present), plotted their spectra & then calculated spectral delta.
  14. Not sure... Digital captures 1 & 2 are identical. Analogue captures are very close spectrally (especially in 20...20000Hz audible range), but not quite the same.
  15. A real PITA trying to align the analogue captures 1 & 2, but here are the spectral graphs: - Spectra/delta (frequency range 20...88200Hz; logarithmic scale): - Spectra/delta (frequency range 45000...50000Hz; linear scale): - Delta closeup (frequency range 45000...50000Hz; linear scale): Some strange spiking near ~48.5kHz frequency...
  16. Universal Music Japan is preparing 100 MQA-encoded CD titles for June 20, 2018 release.
  17. A FLAC snippet of track 01 Pulse taken off Reich: Pulse/Quartet MQA-encoded CD...
  18. ^^^ As per Explorer2 manual, DAC's green light means MQA, blue - MQA Studio
  19. ^^^ BTW, the MQA light that comes up on my Explorer2 DAC when the above CD plays is green (not blue)...
  20. Here is the mqascan result of Reich: Pulse/Quartet (2018) MQA-encoded CD: ===== [01] Pulse.flac ===== 0000ac38: MQA signature at bit 8 0000ac38: [5] datasync magic 36: 0x11319207d stream_pos_flag 1: 0 pad 1: 1 orig_rate 5: 0x01 [88.1 KHz] src_rate 5: 0x00 [44.1 kHz] render_filter 5: 4 unknown_1 5: 0x08 unknown_2 1: 0 pad 2: 0 mq
  21. It's not so easy to spot, but is pretty clear on the graphs I posted earlier (graph A is an MQA-decoded+rendered track & graph C is a 2L's DXD source track).
  22. MQA must be using the same filter in both downsampling (preceding folding) & upsampling (rendering) stages: A 30kHz spike on MQA decoded+rendered track is an alias of 58kHz spike on DXD source. Two ~50kHz spikes on MQA decoded+rendered track are images of two ~38kHz spikes on both DXD source & MQA-decoded (24/88) version.
  23. That Mozart track has some in-band filtering applied to MQA-ed audio (B; decoded + rendered version from Archimago's test) compared to its DXD source (C): - Spectra + delta: - Spectrum delta (close-up):
  24. I attempted one a while ago... & failed.
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