YouTuber claims to have passed blind test on different digital CD transports

[boxerfan88]

That would only rule out bitstream errors, not jitter/noise induced over S/PDIF connection.

Actually more than that, the digital output, in my view (I am not expert in this) should be the result of the CDT laser pick up mechanism, plus error detection/correction, plus digital output driver.

If the digital output of the 3 CDTs are the same, then we can conclude the digital bits/bytes coming out of the 3 CDTs are identical, and therefore should sound the same.

The above was not proven in the video.

 

[boxerfan88]

But then you would basically loose properties like: signal level, jitter, reflections, shape of the digital signal, frequency spectrum etc. which may or may not lead to 'possible issues'.

That’s why a good DAC must be used for the test. DAC should have good isolation from the digital in, and reclocking to minimise impact of jitter.

Ideally a good DAC should output same sound if the incoming bitstream is identical (be it from CDT or streamer or PC or whatever is upstream).

 

[restorer-john]

In my opinion, it would be considerably more useful to be testing the relative abilities of the various CD transports/players when it comes to reading out of spec, damaged, eccentric and warped CDs. As time goes on, and less players are made, the discs themselves become damaged and less perfect. The older TOTL players are phenomenal in their abilities to track grossly damaged discs- I know, I have a lot of them and the test discs to prove it.

 

[solderdude]

That’s why a good DAC must be used for the test. DAC should have good isolation from the digital in, and reclocking to minimise impact of jitter.

Ideally a good DAC should output same sound if the incoming bitstream is identical (be it from CDT or streamer or PC or whatever is upstream).

But here's the thing... what if one uses a rather crappy DAC (that the owner thinks sounds fabulous) but has poor inputs then there could be differences detected that are not caused by the same data being spewed out by transports but one of them being electrically (or optically) so far out of the 'expected' input level range that there could be noises, ticks, etc and one might think there is an audible difference between transports while in reality the DAC is 'at fault'.

Of course we all know that the exact same data (which is essential here, there could be upsampling or some digital filtering going on) with good enough signal quality will always sound exactly the same on one DAC. The fact that people here differences is of another origin in such case. This is hard to swallow for golden eared audiophiles.

 

[BDWoody]

I think we can close this thread.