HiEnd comparison between the past and the (possible) future...

[Sndrox]

Hi everybody,
probably not the first time you read something on this but never really found a clear answer.

I have a couple of Martin Logan Aeon i connected to my YBA Integré, the source is a Proceed PDP2 DAC.
I have two different sources, the PDT2 Proceed CD Player connected via digital output and an Apple Airport Express + a jitter eliminator (Monarchy Audio DIP), same digital connection to the DAC.

I am ripping the whole CD Library into my iMac using Apple Lossless format.
The quality is absolutely great, compared to a very good CD Player but the Proceed PDT2 is absolutely better, the question is WHY?
Where do quality is lost?

I've been tried to find a previous answer to this with no luck.

Thanks for your postings,
Sandro

[IVB]

Native CD format is something like 1Mbps. Apple lossless is something like 300-400Kbps. Even FLAC is something similar.

I don't know this as a *fact*, but i have a hard time believing you can throw away 50-75% of the information and not lose anything.

What I haven't yet tried is not converting formats, leaving in .WAV format.

[Sndrox]

Hi,
I've tried with native WAV format too (but some experts says it's not the original Audio CD format, it's a representation of it), same behaviour, same quality (compared with Lossless formats).

Has got to be something in the way PC read the Audio Tracks.
Professionals reports the only way is to connect a very good quality CD Player digital output to the PC, this way you will not lose anything, the hd representation will be "perfect".

I think there has to be a way to overcome to this...

Sandro

[noddin0ff]

So, you have 2 digital inputs into your PDT2 DAC? One from the CD player, one from the Jitter eliminator that the Airport express feeds into? Try removing the jitter eliminator. A good DAC shouldn't need it. And there shouldn't be jitter problems anyway, not the bad transport kind since you're not using a transport for the PC files. You could also try switching the inputs into the DAC?

You don't throw away any information in a lossless format. It's lossless.

I suppose you could blame the importing of tracks by the PC, but really I would think that the error rate on writing a file to a computer would be very very low. If computers made errors left and right they wouldn't be very useful. You could try copying the audio file to the hard drive first (drag and drop or whatever) and then convert it to lossless. That way you wouldn't be doing it 'on-the-fly'.

If you have a digital out on your computer, you could bypass the airport and the jitterbox and see if it is the signal path.

[noddin0ff]

Oh, and turn off any EQ your software might be applying to the output.

[Sndrox]

GREAT!
Couldn't believe this at first, just removed the DIP and plugged a simple and very low-cost optical to electric digital converter (the PDP2 has only electric digital inputs) and now it's same quality with PDP2!

What a pity for a 150 € DIP...

In your opinion,
should the digital output from the PC be even better than the PDP2?

Sandro

[noddin0ff]

Wow. Glad it was so easy. I don't have any reasoning why the jitter/DIP made a difference; it just seemed unnecessary. Sell it before someone else reads this thread! :-)

In my opinion, bits are bits. A good DAC will compensate for most errors that are likely to arise. I don’t think there should be a difference…but

…my subjective, non-rationale, and ignorant opinion would be to prefer a good CD player over a computer because I just don’t fully understand what goes on inside a computer between the file and the digital output or as it passes through music software. (Of course, I don’t fully understand CD players either…).

I have a cheap USB DAC on my laptop. But I know it doesn’t get a raw PCM from the computer because I can EQ the signal and adjust the volume with iTunes even if I’m using iTunes to play a CD. That implies to me that the software is messing with the signal prior to digital output. If I was after sonic perfection I’d want the signal passed directly to the DAC. I know a CD player with a digital out would do this. That would be my preference.

Happy listening!

[Sndrox]

The full story:
The DIP made the difference when I was using (as a optical to coax adapter), another DAC (Micromega), it has an coax digital output besides its analog outputs.

The digital coax output of Micromega feeded my PDP2 DAC.

At that time, removing the Micromega and inserting the DIP made a big difference therefore I thought it was a jitter problem.

For the "inside the computer" thing, iTunes works with lossless protocol and lossless is lossless even there, as you remain in a "data" environment there's no quality loss, just unplug the equalizer.

Sandro

[noddin0ff]

For the "inside the computer" thing, iTunes works with lossless protocol and lossless is lossless even there, as you remain in a "data" environment there's no quality loss, just unplug the equalizer.
Sandro

Yes, the files you save are lossless. But, regardless of the file quality, if I adjust the system volume on my laptop it attenuates the [digital] signal going out the USB port to the DAC. If I lower the system volume, the volume downstream of the DAC goes down. So, the digital info going to the DAC is clearly not the same as the digital info that would come out of a CD player (the CD player doesn't attenuate the volume of the digital out). My conclusion is that iTunes does process the digital signal and from a 'purist' point of view, that is bad.