Saturday, August 15, 2009

New media

Recently, I blogged about the possibility of CD players disappearing from the scene.
A member of the Singapore hi-fi and AV website xtremeplace.com posted some comments. I forwarded his comments and queries to TK Han of Reference Audio in Singapore and I thought I should share Han's answers for the benefit of the community of audiophiles.
This is because music downloads for high-end components, using notebooks and MacBooks to play Apple Lossless and WAV music files, using Hard Disk players, ripping CDs and hooking up NAS systems are a relatively new trend which is evolving rather quickly. It is in this sector that the iPod generation will clash with the diehard purist audiophiles who still swear by tubes and turntables.
Frankly, I have a lot to learn about this new media....

I don't believe iTunes Store sells Apple Lossless or WAV files yet
Yes this is true. At KLIAV we played a number of music file formats in various resolutions including iTunes downloads, (very few), which were the low-resolution stuff. We did play "native" high-resolution music files in 24-88.2, 24-96, 24-176.4 and 24-192. And of course a series of Red-Book CD-level files as well.


But there are a number of sites, including Linn Records which does support HD audio downloads.
We did play some samples from the Linn catalog - Carol Kidd and SCO Mozart pieces. They were 24-96 and 24-88.2, respectively. We purchased these from Linn via download. Our other high-resolution music files came from Chesky-HDTracks, Reference Recordings HRx, 2L-Norway, Kent Poon of Hong Kong, High Definition Tape Transfers, etc, etc. These had resolution up to 24-192.


That said, I have read one review which claimed the HD downloads from Linn (and a few other sites) don't sound good. Something abt the DSD to hires PCM conversion apparently.
Our experience had been otherwise, actually. But the music contents were not always "universally appealing" from some record labels. But, it is also true that there are quite a bit settings on PCs and Mac that one needs to pay attention to if the bitstream is to be played at the DAC accurately. Any errors or interventions by the PC OS, will cause the sound to suffer to a very great extent. Not many audiophiles are aware of these yet. But, the pro-audio people who need to work on the music files are very conversant with the setting requirements. We don't think DSD to PCM is an issue, really. Many great CDs today were recorded in DSD. And CD is standard-resolution PCM.


FWIW, I listen to redbook primarily through my Duet streaming from my NAS/PC so I do see how CDs could be losing their relevance. I'd like to have a listen through kelso's SB3. But in the high end, I think most transports still have SB/media players beat.
This may be true when one compares the same CD, ripped and played through the PC at its native 16-44.1 and the CD on a high-end transport. It has to do with, again, how well the digital bitstream is handled till it gets to the DAC to be decoded. Don't forget that before the CD was pressed, the recording actually went onto a PC hard-disk/s for a number of post-processing - mixing, mastering, etc, etc. So, done right, PC-audio should be very good. Many highend transports and DAC have buffers, error corrections, jitter and clock accuracies, etc, etc, to ensure that the bitstream is very precise when it gets to the DAC. This is of course done at a relatively high cost compared to a PC. A basic low-end PC, redeployed for the task of music play-back, as is mostly the case today, may not handle the bitstream anywhere as well as a dedicated highend CD transport. But the PC does hold great potential, especially for high-resolution audio files - 24-96 and above.


So as a reviewer, how did the Weiss sound? Was it using the upsampling algorithm plug in as reviewed in Positive Feedback? I am more interested in how it handles regular redbook audio since that's the primary source for most of us. I know the PS Audio Perfect Wave combo didn't seem to improve redbook even with the upsampling enabled."
The Weiss Minerva we demo'ed does not upsample. it just has the capability to decode all sampling rates up to 192kHz and word-lengths up to 24bit. But, we did demo upsampled music files that were originally red-book format - 16bit 44.1kHz. They were upsampled to 24-176.4 using Weiss's software based professional sample rate converter, SRC - SARACON. Upsampling does not improve on the original recorded sound quality on the CD. It does make a number of things better/easier for the DAC and the resulting analog signal consequently may sound better than the CD played as is... it's an open debate, still. But, do bear in mind, there are good SRCs and there are bad SRCs; cheap & free SRCs and expensive SRCs... Some SRCs only do simple rate conversions, not word-clock dithering from 16 bit to 24 bits... Some SRCs are simplified for quick calculations on slow computers, etc, etc. So, a simple upsampled music bitstream does not always guarantee better sound....

Let's hope we can all learn something from this. I think it's a matter of time before hires downloads and hard disk players will become commonplace...

3 comments:

  1. hi Lam - I for one, have fully migrated to HDD based playback and never looked back. No more spinning disc and sonically, I'm very satisfied! The convenience factor is another major plus point
    DS

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  2. DS, can I know what set up are you using for your playback? Do you listen through headphones or a proper system? I've heard a few but thought a proper transport would have sounded much better. I'm also exploring the Ipod or server as source system but have not been convinced yet. Maybe, your set up could be the missing piece.

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  3. hi The Wise One - I dont listen to headphones, but a normal, 2 channel rig. My PC front end basically comprise of a HP laptop, with all the uncompressed,lossless files stored in an external HDD, wirelessly streamed to a heavily modified Squeezebox unit that outputs digital to an external DAC. Hope this helps. DS

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