Any experience with Resolution Audio Opus 21 CD Player

The problem I have had is that most of these CD players are fussy about the quality of signal input via SPDIF or Toslink. I am currently trying to find out for instance just what Apple do to the signal when sending it via Wifi. They sure don't send unprocessed WAV files. I bought the CD7 for the very reasons you mention. The Sim also has that facility as does the Opus 21.

Sadly the CD7 will not reliably lock onto the computer's output in my experience, nor will it accept any form of Bitstream which is the only output from say a PS3.

Having said that, I've yet to hear a better player of CD's and music in general in my system so the Marantz stays - it just makes computer audio more expensive than I consider worthwhile at the moment. Unless I can get a pure enough signal for the Marantz to read.

 

www.phasure.com

still in an early stage but very promising

PS. disregard a silly name

 

Like you, I'm not convinced by the use of a computer for high-fidelity for a variety of reasons:

1) formats currently available are all compressed to a greater or lesser extent

2) soon someone will say - aha other computer circuitry impedes ultimate sound quality - so let's isolate just what's required for the music - this means a standalone harddisk player with just audio connections -i.e. an mp3 type player

3) In pure theoretical terms, the only difference I see between using a computer and a CD player is the type of drive and the file formats

- Say lossless formats were to be brought to the same standard as CD files , then all you really have is the convenience of higher capacity offered by hard disk as opposed to CDs. The computer/server is still reading off bits and bytes from a moving platter using a head.

- apart from conveniece of capacity , I don't really see the server option as a new or improved technoplogy over CD - going back to basics it breaks down to file format and type of drive

 

do you use your ears when comparing playback methods?

 

Yes but I am trying to break down the hype surrounding what is sometimes being touted as the latest and greatest in hi-fi

The point I'm trying to make is that there is really no new technology here...in fact currently to go to the server/Dac route you have to downgrade to lower resolution file formats

 

Lossless music files are just this, compression without any loss in quality.

A cd can be ripped to lossless files (ie, FLAC) and then re-recorded to be identical bit-for-bit to the original CD

 

I certainly do, and really wanted the HD server based solution to work. It's so convenient. But alas, none have yet come close to my CD player, which I put down to the interface between PC and DAC.

 

Here's a review of an Apple MacBook + Hagerman HagUsb USB-to-S/PDIF Converter + 47 Laboratory Shigaraki DAC:

http://www.6moons.com/audioreviews/musicloverdigital/digital.html

I wish the reviewer had compared the Apple to the Shigaraki transport and then we would all know... Price is not too different.

 

I think that's the point really - he doesn't at any point compare that setup to the transport and I would imagine that's deliberate.

Having used an almost identical setup ( MacBook Pro/ M Audio Firewire/ 16bit multibit Dac) I would absolutely agree with his comments - but add that the built in CD transport sounded considerably better to everyone who heard it.

 

Saw this elsewhere on the forum from which I concluded that FLAC was not same resolution as Cd but I could be misinterpreting it (or certainly taking it out of original context):

 

FLAC is unique as it uses a lossless compression algorithm, which can make file sizes smaller without discarding any information, whereas MP3, for example, discards information to get file sizes down.

with lossy compression, it is true that more kbps = higher quality, but lossless is just that, regardless of the kbps (with FLAC, some types of music can get down to 400kbps, wheras others need around 1000kbps, both are lossless)

Think of it like zipping a file. If you zip a document, you get a smaller file, but all of the words are still the same. I suppose MP3 would be the equivalent of compressing the document, and removing the vowels to slim the file down further. You can still get the general idea of what it says, but its not the same level of quality.

 

Thanks for clarifying Mr Tad

 

Zipping an image file makes no change whatsoever, same goes for an AIFF music file copied from a music CD.

I'd dare say that any format that makes this file smaller will not be lossless just as a JPEG isn't.

How much of that loss you can actually hear is another mater.

 

Wrong. Rather than cover the same ground again take a look at this thread:-

https://www.audio-forums.com/as-rediect/showthread.php?t=16858

 

Interesting. Working in (importantly) sighted tests, I could clearly hear the damage done by Apple Lossless. Now whether that's my imagination is a good question - and it's entirely possible/probable that it is.

But given the damage we know that digital decimation does when going from say a 96khz 24 bit master to a 44.1khz 16 bit CD, is it feasible that the conversion process itself from one file format to another becomes in some way audible?

 

The idea of lossless compression - its bit for bit identical to the uncompressed source file. Playing a CD on a traditional hi-fi transport and playing it from a PC with a lossless audio file *should* result in the DAC getting identical 1s and 0s.

In practice, this of course won't always be correct (if it was, the every transport out there would sound identical as well). Hearing differences between different types of compression and the original source file could be a result of different forms of processing in the respective players.

The thread Dev linked mentions hearing a difference between apple lossless and FLAC. This could be as a result of playing one file in iTunes and the other in Foobar, one going through windows k-mixer and the other using ASIO, or whatever. This could even be a result of a player having a less than efficient/correct algorithm for actually decompressing the audio, or high CPU useage resulting in higher latency or incorrect timing.

 

I disagree with you here: even if it "could be" possible with sound files it isn't with image files. I know little about sound but I can assure you I know about image files.

 

and I don't think the zip analogy is valid because ZIP can't compress data.

Edit:

because ZIP can't compress data on a WAV file.

 

And there's at least one very important bit of information missing from a BMP file: the color space tag.

 

It certainly is possible, Lev-Zimpel, Deflation, RLE, all are used to losslessly compress image data. Use (just for one example) LZW compression on a TIFF file. Then open both files and do a bit for bit comparison of the compressed and uncompressed file. They will be identical, bit perfect copies. This is just one example. If it was impossible to losslessly compress image data then digital imaging would be in the dark ages.

Compression algorithms know nothing about the type of the file they are compressing, it makes no sense to say a compression algorithm (lossless or lossy) can compress one file type (say, audio), but not another (image data).

Well, it can, but it won't necessarily manage to compress the file very significantly, as the file may already be efficiently compressed.

I have no doubt audio playback from a HD server and a CD player may show differences, but if the audio stream is losslessly encoded, it isn't because the HD server is serving up lesser-quality audio because of compression.

-- Ian