Print Page - Phasure NOS1 and HDCD

I split this post from under the post here : Re: 1000 HOURS ON THE PHASURE NOS1 (http://www.phasure.com/index.php?topic=1710.msg17236#msg17236).
To put it (back) in the Phasure NOS1 board may seem strange, but let's say I expect the people judgeing HDCD with an NOS1 may at least theoretically judge it more equally to my own judgement. I think on this matter it is important.

For some more reference, also see this post from my hand : Re: 1000 HOURS ON THE PHASURE NOS1 - HDCD (http://www.phasure.com/index.php?topic=1710.msg17229#msg17229) or the first post in that topic (from Juan).

I think Jazz Hat is not the best example, because/or something is wrong with it.

First of all, I tried to determine the difference in output level (with/without HDCD), and as far as I can judge (by ears) this is 7.5dB.
I didn't hear you talk about this, so this should be "error" #1.

Next, I noticed that after decoding it is all the way up to the maximum level. This means it will be clipping. This by itself means that Peak Extension is *necessary*. This is #2.

Then I realized that I (XXHighEnd) treats the HDCD album as if it will be played like that. Logic of coure, until we decide not to do so. Thus, the beforementioned maximum level, is the level after the decoding, and there's no facility at this moment to work with the undecoded level (and also : currently we can't even see that, and it might well be that even undecoded it's at max). Error #3.

At comparing a little with other HDCH albums, I found at least one with the MaxVolume tag in the Analysis file, but the SPL lacking. This is not right, and I don't even know what happens in that case if it were for Volume Normalization (which I always use). Potential error #4.

At this moment I'm suddenly quite confused what's really going on with the standard -6dB and how this is to be related to my own Peak Extension's -3dB;
Maybe my 7.5dB difference judgement is wrong and it must be 6dB, but the difference seems too much to me. The maximum digital level in there (decoded) looks wrong to me, but a sort of makes my judgement about the 6dB (7.5) consistent.

Whether this is a somehow bad album or not (regarding HDCD I mean) I don't know and whether the HDCD decoding is bad, I don't know either. But one thing is clear from the net result of whatever : this is not allowed to be played without Peak Extension (so, that must be active). This is strange of course.

What really must be done in XXHighEnd is getting those volume levels Normalized. So, one MaxVolume for "with HDCD Decoding" and one for without. SPL the same.
On this matter I found the Jazz Hat without HDCD decoding immediately better sounding, but, it ... ehm, was way louder. Huh ?

Well, I am trying to write this today, after the happening yesterday and while I'm quite sure of the above, I can't find/make the logic of it right now. So, error #5 might be that because of the way it works *and* I used the Normalized Volume, things backfire, and the combination with the SPL (which was way low, something like 1120) causes the volume to go way up, while ...

Well, at least I am sure that the Volume Normalization Analysis happened (which happens when the album is played for the first time -> didn't play it after the Volume Normalization has been introduced), and I am not sure anymore whether HDCD Decoding was active at that time. The low SPL will make it play way more loud compared to a more normally compressed album, *if* the headroom is there. If you're not using a pre-amp and with Peak Extension on, this headroom isn't there in the first place, so it will play too soft.

Ok, don't try to understand this, because I don't know what happened (in what sequence), and so I now can't understand it myself. It is very clear though that comparing is quite tedious, but, that by itself I seem to have done right (equalling the volumes manually).

Using the second track, and mainly from off 4:49 into the track, at first I was sure that without HDCD Decoding the strings of the (bass) guitar where more buzzing (one reason to compare with an NOS1 at hand, because another DAC won't exhibit this at all). Later, without really paying attention to it, but when I had the levels right (which wasn't so at first) I was quite sure that the brushes and faint in the back snare hits were more clear with HDCD Decoding. After comparing back and forth I decided that with HDCD Decoding the faint drums were far more spatious as well. And in the end I wasn't sure about the buzzing of the strings anymore at all.

I wouldn't put any money on this at all, hence if there's really a difference it's marginal. But one thing I know : not having the levels equal will destroy all comparisons, and the lower levelled one will sound more dull, less spatious (largely !).

Day before yesterday I played Keb' Mo' - Slow Down throughout, an album which I play regularly because it's actually always sounding good (a kind of Dire Straits from the earlier CD era). I never pay attention to HDCD being in any album, and I always have it Active. This time though, I switched it Off, and the album sounded as never before (so good). Sadly it also was the first time I played it with a completely newly "tuned" system as a whole, new XXHighEnd software explicitly changing sound, so what to tell about it really. But at least it didn't sound worse.

Generally I'd really have to say that HDCD encoded albums always sound like having a higher resolution. I always notice it. Similar to that Jazz Hat track and the drums I described above. This higher resolution to me sounds better than the real "hires".
So, I think I want to say that HDCD encoding + decoding really makes it better, which doesn't say a thing at all about how much better it will be on an official machine (with HDCD decoder chip). I have no experience with that.

I guess the next XXHighEnd version will solve the problems mentioned in this post. Better not compare furher before that's in.

Peter

PS: Sorry for a confusing post. I'm sure I wrote as dizzy as I feel. :yes:

XXHighEnd

Ultimate Audio Playback => Phasure NOS1 DAC => Topic started by: Scroobius on June 14, 2011, 04:54:51 pm