Sound Quality of red book CDs vs.streaming

If using Roon or Android Hi-Fi Cast (most any app/software except Google’s own), the jitter in the ChromeCast Audio is better than -275dBFS (better than 45Bit). @audioengr’s re-clocker will actually introduce more jitter in this case. It’s only if you Cast with YouTube or your Chrome Browser will the re-clocker actually reduce the jitter; however, any good DAC will be audibly the same for cheaper, $700 for a re-clocker is silly when a $250 SMSL SU-8  DAC has jitter below -120dBFS, what is considered out hearing range (some say 140dB), and accounting for room noise, it’s more than enough.

@audioengr

You don’t give specs as to what dBFS or psec your product is; you’ve stated 7psec before, so I’ll assume that, the ChromeCast Audio has less than 4psec (better than -275dBFS / 45Bit). If your product is better, I’ll retract my statement. Again though, even if your re-clocker was 0psec, the differences are not even close to audible, so spending $700 one one would be waste of money in this instance.

Even the $100 Khadas Tone board DAC has a J-test result of -135dBFS, which allows for more dynamic range than we can hear in a room (say 140dB max and a room noise floor of 30dB, so 110dB; and that 140dB is generous, most music is mastered to 105dB, with some orchestral/classical getting to 120dB).

A ChromeCast Audio hooked up to a “cheap” Topping D50 DAC, using normal cables, produced a J-test of better than -130dBFS, also better than our hearing in a room.

Using a DAC to measure jitter using J-test is insufficient and the wrong way to characterize digital sources. It’s okay for characterizing the jitter added by a DAC, but not for digital sources. Digital sources are accurately characterized only by DIRECT measurement, not with a AP system. It must include both the period distribution and the spectrum plots.

The better than -275dBFS is a direct measurement. However, the jitter out of a Topping D50 with the CCA as it’s source was what I was talking about as being better than -130dBFS. So while that latter test doesn’t detail the jitter exclusively from the CCA, it gives the total jitter of the system, which is better than human hearing in a residential room.

@audioengr  
 
I’d genuinely like to know why. ASR measured the jitter reduction inherent with his AP by doing a J-test with a Toslink loop, then measured the Toslink output of the CCA (using the same cable I would assume), so if the jitter reduction was any worse, it would should up, and the differences were near non-existent.

@audioengr

You are talking about measuring the picoseconds worth of jitter (which does need to be in the MHz region). I am talking about doing a J-Test and finding out how the jitter will affect the passband after being reduced with a DAC, which would show up as any added noise to the waveform. It’s the same test Stereophile uses. I do not know the psec equivalent, but it is stated as worst case scenario, and when paired with even a cheap-ish DAC like the Topping D50, any jitter with using the CCA via optical was reduced to below -130dBFS, much lower than any residential noise floor.