S/PDIF to CDP vs direct CD playback sound difference

snowmanp

Member
2020-01-17 3:59 pm
Toslink to CDP vs direct CD playback sound difference

Recently I put together a Raspberry Pi network streamer for my father, who uses fancy speakers connected to Mark Levinson 390s CD player. According to him, although the sound quality is quite nice, it doesn't provide the full "sensation" of a sound coming from the direct CD playback when comparing a same track. I won't be home until a few days so I haven't had the chance to hear the difference myself.

For Toslink output, I'm using Hifiberry DIGI+ PRO attatched to the top of Raspberry PI (ALSA, default config) and use Airplay (lossless) to stream TIDAL (lossless). Airplay volume is forced at 100% regardless of device volume.

I try to stay away from differences that I can't reasonably prove (because I'm broke) and I don't have the greatest ears either. That being said, I cannot understand how this particular audio chain can suffer such quality loss. Everything is digital until it hits the CDP, and I don't think there's a fault within its course. Hifiberry and toslink connection will add jitter for sure as it is not bit perfect, but it won't be anywhere close to being audible. One possibility is that the CD player is not handling digital input the same way as it reads a CD, but I doubt it.

Is there any hidden "gotcha" I've missed?
 
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I would imagine the first thing to consider is if you're comparing like with like with respect to recordings. The CD recordings and those provided by Tidal may be mastered differently or may be polluted/improved (delete as appropriate) by MQA. There's quite a lot of discussion of this over on Where HiFi and High Tech Converge

Of course, there's always expectation bias. I assume the comparison was a sighted one.
 

snowmanp

Member
2020-01-17 3:59 pm
Yes, it was a sighted one.

Probably not a different master (assuming non-MQA tracks aren't touched) because he specifically mentioned the lack of MQA option on those tracks. I'll let him test with the ripped version of the track once I get home.

Another thing I'm suspecting is volume mismatch and the loudness bias. Can't account for this one without a proper hardware.

Or it could really be that the digital output from Hifiberry Digi+ Pro is prone to more jitter than I thought, which I have no way of testing either.

How are the reputations for Hifiberry Digi+ Pro Toslink output? I did uncover some threads complaining about the jitter and inaccuracy.
 
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Yes, it was a sighted one.

Or it could really be that the digital output from Hifiberry Digi+ Pro is prone to more jitter than I thought, which I have no way of testing either.

How are the reputations for Hifiberry Digi+ Pro Toslink output? I did uncover some threads complaining about the jitter and inaccuracy.


Jitter may be measurably higher, but as you mention in your first post, likely inaudible. I don't know what the measurements are (presumably you have found them from your searching), but it may be worth trying to simulate that amount of jitter using the advice here to see if it is at an audible level.