Thanks Chris. The Core in question was a pre-production unit that I was reviewing. The unit came without a hard disk, but recognized my UnitiServe’s downloads folder as a store, so rips went there. That made it easy to compare the Core rips with those of the UnitiServe (WAV rips in all cases). I was not expecting a difference, but increasingly found myself less engaged with the Core rips. I set up a playlist of Core and US rips, then, using random unsighted playback, noted which version I thought it was, followed by a visual check. On repeated trials, I fared better than chance, correctly identifying the rips about 75% of the time.
An example: The Francis Cabrel’s track “Elle m’appartient, C’est une artiste” begins with an accordion and a brief guitar intro before Francis Cabrel sings. With the Core rip, the accordion was a little more finely resolved and cleaner ; when Cabrel’s voice enters, it was in a narrow band in the soundstage, just left of centre, lacking body. The guitar solo later on in the track was clean and clear, but again lacked body (or the human touch). The guitar was heard more than felt.
Moving to the same track on the Serve rip, the accordion was less finely resolved, but seemed to have better flow. The upper chest component of Cabrel’s voice was more present, with a consequent wider spread of his voice in the sound stage. It just sounded more human. By the guitar solo, my analytical brain had switched off and I was just transported by the music.
This pattern repeated itself many times over three weeks of going back and forth between the Core and the Serve.
When listening on the Core, I found myself picking up my iPhone more often than when listening via the Serve, where I was less easily distracted, the music commanding my attention more fully.
I also tested the rips using the ‘chills’ (goosebumps) reaction, precisely because it is involuntary. It is very difficult to ‘will’ oneself into it. I have a few tracks that reliably produce the reaction. On the Core rips, the reaction would often start at the appropriate point in the music, but would not be as intense as with the Serve rip.
Overall, the Serve rips did a better job of connecting me with the human performing the music and the human who composed it.
I’m fully aware of how our biases can influence what we hear and how we react to music, which is why I raised this on a forum thread in 2017. Five members volunteered to listen to both rips, blind to the source of the rip. The first reply came from a forum member who is also bass player. He consistently picked out and preferred the ‘B’ rips (UnitiServe).
Results from the other four listeners were not as categorical, ranging from a slight preference for the Serve rips to no difference. Overall, in six listeners (including myself), three noted a preference (from slight to strong) for the Serve rips. While the result wouldn’t pass a test for statistical significance, it is the consistent direction of the preference (when noted) that is interesting. One listener remarked that he couldn’t tell the rips apart on casual listening (on random playing), yet when he stopped thinking about the sound and just tried to relax into the music, his score was 5 to 1 in favour of the Serve rips.
Analysis of the rips showed bit perfect copies of each other excepting the leading data bits (zeros), a difference in offset.
The forum thread caught the attention of Naim’s former MD, Trevor Wilson, who reached out to me to investigate further. He compared Serve and Core rips and also found a difference, preferring the Serve rips on some tracks, and the Core rips on others. Different offset adjustments were evaluated at Naim, the firmware was updated, and the delta disappeared.
With the update, I could no longer reliably tell the Core rips from the Serve rips. On 30 random plays of Brush with the Blues, I guessed correctly 11 times. On another of my test albums, I guessed correctly 15 times out 30. Overall, 26 out of 60, so no better than chance.
Still, I was at a loss to understand how a minor offset difference could alter sound quality. Trevor’s theory was that “The music is left/right 16 bit data packet. Maybe the alignment of the non audible data helps align to the internal bus architecture thus it takes one CPU cycle not 2 to get data out.”
Stranger things have happened.
Systems used to compare the rips were as follows:
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UnitiServe / S/PDIF into a Resonessence Labs Mirus Pro DAC / 252+SC / Olive 250 / NACA5 / self-built two-way 8 inch floor standers.
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UnitiServe (from sys 1) / UnitiLite (or Naim DAC + Supernait2 ) / Bis Audio Vivat speaker cable / Graham Audio LS5/9
Jan