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Discussion Starter · #1 ·
I've been reading this forum for quite some time now and was wondering about something a few people have said to me.


Basically, the large majority of people here think they can get superb CD (or WAV) playback from a PC with, say, an M-Audio card installed. They also tend to agree that they will match a good quality CD player.


Well I agree that we can get similar DAC's on a soundcard as you would in a STB, but what about the rest of it? A good quality CD player will include features such as:


Dimming features on displays to avoid interference.

Specially designed loading and spindle mechanisms to avoid vibration

Specially designed PSU's to avoid interferance



Now PC's have none of this, with the addition of extra EM interference from the PC components. Are we really saying the a £50 PC CD-rom drive is just as good as a STB drive? Or are we saying that Hi-Fi manufacturers have wasted all this time adding these extra features to improve sound quality?


I think the general gist is that a PC is reading the audio off a CD bit by bit through the IDE cable. Is that what people think is making the difference? If so, I'm sure Hi-Fi company's would have used the same method themselves by now.


I have (maybe foolishly) made a bet that my friends £1400 Roksan CD player will not sound any better than a well built HTPC!


His player has the following spec's:


Super single bit enhanced digital to analogue conversion system.

Gold plated RCA analogue output connectors.

Separate transformer and power supply for the analogue output stage.

ROKSAN patented Laser Light technology for more accurate reading of the laser.



I just want some general comments on this, as I think opinions on this matter have gotten somewhat confused (or maybe its just me :))


Vic
 

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Discussion Starter · #2 ·
Sorry I just though of another point:


If my friend ran the digital out of his Roksan, he wouldn't even be using the DAC's inside it, but his Amps instead.


No Dac's used

+

His CD mechanisim not making any difference.

=

A £1400 CD-rom drive!
 

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This exact subject has been discussed several times in the past year or so using even more expensive players than your friend's ROKSAN. Check these threads:
I hope this will answer many questions. The best test is to try yourself.


PS. Where does your friend live?
 

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Discussion Starter · #4 ·
Thanks


I will check out these links, but I said, it's coming to the point where I just don't believe peoples audio perceptions. If what these links are saying is true, then STB CD manufacturers are talking/making bo**ocks.


Personally I can't tell the difference between my laptop playing a CD through my Denon amp and my £400 Technics playing through the same amp! :)


My friend lives in Wincmore Hill, North London. Why?
 

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Discussion Starter · #5 ·
I've read the links and they are basically testing via digital out. What about analog out? As I said, why would you spend £1400 on a CD player if you're not even going to use the DAC's. E.g you may have analog amps.


For everyone looking at this and thinking it's another bloody soundcard discussion, that's not what I'm getting at. I trying to figure out, if you can indeed use a soundcard/CD-Rom with analog out to beat a £1400 CD player with analog out, then surely there is something seriously wrong with the Hi-Fi industry. In the sense that they are implying that information being pulled of the CD by the laser/mechanism is just as important to ovarall sound quality as the DAC's used.


A £50 CD-Rom just shouldn't read the pit's in the disc as well.
 

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slikvik,


obviously there is a 'fiddle' factor present when using HTPC. Audio/Video component manufacturers are responding to a demand from well developed market that is willing/able to pay the prices it is paying. Only if significant number of potential buyers start switching to HTPC, prices may become affected.


I live in Hammersmith, we can organise ourselves and do a test.
 

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slikvik


What you may find is that the £50 cd-rom reads the bits better than the expensive hi-fi....


I once had a chat with a speaker designer and he refered to most of his competitors in the HiFi world as "the noisy end of the home furniture market" which I thought was a good description.


If you do the test make sure it's double blind and that both units are on at all times, that way there should be no clues as to which unit is in use.


Also remember to take along a box of tissues for when he realises he can't tell the difference or even picks the "wrong" one :)


John
 

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slikvik,


In one of the post I make a passing comment that the 2-channel analog out from my RME DIGI96/8 card sounds better than digital out into Lexicon MC-12B (in the first case Lexicon is set to analogue by-pass mode, while in the second case Lexicon own DACs are utilised).


Well Christmas is coming with lots of free time. Lets come together and do some hobby activity. We'll need some expensive gear thou!
 

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Quote:
I have (maybe foolishly) made a bet that my friends £1400 Roksan CD player will not sound any better than a well built HTPC!
How big is the bet?
 

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Quote:
I have (maybe foolishly) made a bet that my friends £1400 Roksan CD player will not sound any better than a well built HTPC
See if you can get him to agree to a "double blind" test.

THIS POST IS NOT MEANT TO START A FLAME WAR ON ABX TESTING. It is meant to help slikvik win his bet.


First, you'll need to carefully match the volume of the two sources. I mean carefully, within 0.3db. Use a radio shack soundmeter, they're pretty cheap.


You'll need a way to switch between the two sources. Presumably you can do that through his pre amp.


Ask him for his favorite cd. Rip the CD (as a wav). Play the CD for him through the Roksan. Then play the CD through the PC. DON'T LET HIM SEE WHICH DEVICE IS PLAYING. Then, RANDOMLY select the PC or Roksan. Ask him to identify which of the sources is playing. Do this 10 or 20 times. If the Roksan is clearly superior, he should be able to easily tell which device is playing each time.
 

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Discussion Starter · #12 ·
The bet is more of a 'once I've proved you wrong I can laugh in your face!' sort of thing. Ya know, mail pride!


Anyway, it's a few months off as I have to build the bloody thing first.


To continue the discussion (and play devils advocate,) can some one give me proven techinical reasons for the following:


1) Would a specially designed CD mechanism not reduce vibration thus improving SQ? If not why do CD players use them.


2) Would a seperate PSU for analog output improve SQ? If not, why do CD players use them?


3) Is EM interference so small in both a PC and CD player that it really makes no difference? If so why turn of VFD displays in a CD player?


4) Is reading the data via IDE 100% bit perfect (or at least better than the other method.) If so, why haven't CD companys fighting for the top spot not moved over to this?



You see my point with this (I hope.) I know there is a lot of BS in the Hi-Fi industry such as cable appearence etc. but they are still fighting for position in the SQ rankings as it [helps] sell more units. I don't see (as my friend has been saying) how the above things would/wouldn't be done if it made a difference to their units.
 

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Without getting into the bits is bits argument, assuming you're using the PC/CD player to output a digital stream then.


1) PC drives can repeatably get exactly the same bits off a CD over and over again so vibrations appears to have no effect on getting the bits off the disk. This isn't to say that vibrations won't effect a HiFi design CD drive.


2) Digital signals aren't sensitive to AC noise in teh same way analogue ones are so just for the "thing" outputting digital power is pretty unimportant.


3) Yep, unimportant for digital. I've heard people claim that for analogue output they can tell the difference between having the displays at different settings I've never heard anybody claim this with digital though.


4) Yes it is bit perfect. As to why the HiFi makers don't use IDE drives, probably noise.


In the HiFi - PC world you are probably best off storing the CDs as wavs (or other lossless format) on a server somewhere and playing them back via the network on an HDless box with a "good" digital out sound card.


John
 

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Quote:
Originally posted by JohnAd



In the HiFi - PC world you are probably best off storing the CDs as wavs (or other lossless format) on a server somewhere and playing them back via the network on an HDless box with a "good" digital out sound card.


John
John makes a really good point here. Considering the original question, "Are HTPC really any good as CD players", in addition to SQ you should also take into account the much greater functionality of HTPC. For instance, I've ripped my 500 plus CDs to one of my computers (APE format - a lossless format). With 'jukebox' type of player/database software like Media Jukebox, this is all organized into several different hierarchies (e.g., artist / year - album, etc...) - now with playlists that I set either manually or based on 'rules', I can play what I want, how I want, whenever I want. Want to play music all day without changing discs? No problem, load your playlist and go about your business. Have an artist that has works spread out among many different compilations - no problem, a couple of clicks and you can see the tracks listed together and play them if you want. Etc...


Due to the size of my collection it was a bit of work to get to rip and organize, but now I could never go back to using discs / standalone CD player.


...just my 2 cents :)
 

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Discussion Starter · #15 ·
Thanks for the reply John, your comments make sense for digital all the way out.


Unfortunately I'm actually talking about analog OUT of the HTPC. Don't forget that some amps (especially non AV amps) don't have digital IN's, so we will be using the internal soundcard DAC, where some of the above questions will have different answers. IMO.


Vic
 

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Vic


For analogue there are some possible arguments for some of the above but I've been very happy with the quality of the analogue outs on an audiophile 2496. No idea how it would compare to a very high end bit of kit but even on anlogue in a properly set up test I'd back a draw over a clear winner from either side. Others who have done similar tests claim good results though, see branxx's links above.


Sherbona


The functionality angle is definitely better on an HTPC, I was getting more at the operational noise aspect which is a problem for most uses of computers. For serious HiFi I imagine a significant cost is getting the player to run silently. The whine of a bog standard ide cd-rom would be too much for most people in a normal HiFi system.


John
 

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Discussion Starter · #17 ·
Is the 2496 the better choice (over the 410) if you just want analog stereo outs? Doesn't the 2496 have better THD and SNR? I think it's also cheaper than the 410.


I think I might go for this card combined with an nForce 2 for SPDIF out.


Cheers

Vic
 

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i personally think that there is a lot of "hype" about the audiophile quality stuff nowadays..


much of the "design innovations" are worth nothing..


i bet that you could listen to a cd from a PC sound card VS the same from a good cd player with the same DAC and you wouldn't see any difference..

all that for a 10 time increase in price :p
 

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Slikjvik,


there are indeed a few very high end players out there that do use PC CDROM drives to get the bits of the CD. The two examples that I know of are the Meridian 800 and the Camelot Roundtable.


What it comes down to is a design decision for your drive. On a traditional vinyl roundtable the quality of the sound is influenced by how stable the rotational speed of the platter is.


In the digital world it seems that you can make a crystal oscillator driving a DAC a 44.1 or other frequencies much more stable than you could ever achieve with controlling the speed of a heavy platter.


Now this is not to say that the stability of a crystal oscillator is not being influenced by EM interference or vibration. However that has nothing to do with getting the bits of the CD. Most of these measures play in the analog domain.


Here is another thought. Most CD players rotate the CD at 1x audio speed. If there is any problem on the surface they might loose a sector and have to interpolate the missing data. If you use for example Winamp with the cdda plugin the drive runs at 8x or 16x speed and would go back try to reread the sector 5 times and in most cases probably get it right. Someone with a Meridian 800 might be able to confirm that this is also what they do.


If you are mainly focused on getting the right bits to your DACs it is almost certainly true (unless something is wrong with your computer) that feeding the bits from a WAV file will be correct more often than an Audio CD player reading the bits of a CD in real time.

If you are using a ripper that is paranoid about extracting the correct bits of the CD and storing them in WAV file format this should give you an advantage right there. (people in high altitudes might want to buy ECC memory to deal with the higher amount of spurios errors :))


There is one minor quirk and that is pre-emphasis. Very very few audio CDs do have the pre-emphsis bit set and are meant to be played back with a certain equalization. When you use your ripper and just store the WAV file that information gets lost and on playback either via the built-in DACs or digital out you will be hearing this. If you happen to know that a particular track requires pre-emphasis turned on you can usually turn on that bit in the driver for digitial outputs but this is not stored in the WAV file and is switched dynamically.


In any case you could argue that a CD ROM drive is better suited for getting you the right bits of the CD.


Hope this helps.


Thomas
 
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