[mattigol]

Hi gang,

lately, I have been researching CDPs and DACs to upgrade my source (a '99 Rega Planet). 1000 US$ and more can be easily spent, even when using budget or used components. Now for ultimate playback - wouldn't it be the most audiophile solution to buy a Mac Mini with a big HDD, rip all CDs to a Lossless Format using EAC (on some PC) and listen through a really good USB-DAC? Wouldn't this method extract purer information than any $$$$ transports plus DIP plus DAC could do on-the-fly?

Thanks for any thoughts...

Matthias

 

[jefemeister]

pretty much. That's basically what I do and I'm very happy with the results. But this solution really only solves the data extraction part of the problem. Jitter is still a factor and, im my estimation, jitter is higher in computer based gear than high quality seperates. A good reclocking DAC should minimize this problem.

Not only do I think it's a great idea from a sound-quality point of view, but it is also super convenient once you have the files on the harddrive. I think of CDs as almost a quaint concept now.

 

[mattigol]

...that coming from a guy with a big name sig means a lot! Last year I bought an iPod 20G and due to the relative lack of storage space and mainly mobile use I never considered lossless. But now that I am thinking about upgrading my home source, the whole encoding ordeal seems like a very reasonable thing to do. I read elsewhere that people recommend external soundcards between computer and DAC. Dont I bypass the computer's soundcard by connecting a DAC directly to its USB port?

I know I am pretty much uneducated as to what EAC really does, but I thought jitter is something it would correct before writing its data to disk.

Are you aware of any good reclocking USB DACs?

Cheers M

 

[Melchior]

Sort of. In terms of convenience without sacrificing any quality yes, but unless you do something about silencing your PC (or if you have sealed headphones) then a dedicated player would be better.

Reducing the noise levels to below ambient is usually enough for most people, and not that difficult. Most importantly get a quiet hard drive (I prefer the Seagate Barracuda IV/5/7200.x series) and a CPU heatsink that has an 80 or 92mm fan. Chipset fans on the motherboard can usually be removed without worry, but it would be best to leave them unless you know what you're doing. If CD's or DVD's are going to be used, read reviews and ask around on the home theater forums about which drives are quietest, Plextors are usually great, I used to have a pioneer slot loading drive that was way too loud during dvd playback and spinup, and I had to turn up the volume signifigantly to drown it out. That was an old drive however, and they've likely improved since then.

Ideally you would want to build a passively cooled PC with the quietest hard drive you could find, and add noise proofing to the case panels. If it's for audio only this is a fairly easy task, as you won't need to worry about raw CPU power and the heat output that comes with it.

If you're going to use it as a home theater PC it's a little more involved as you'll require a fairly decent graphics card along with a capable cpu, which will either require HUGE passive heatsinks and a couple low speed fans, or you'll need to put up with a very small amount of ambient noise.

 

[sgrossklass]

The basic idea of eliminating the transport by means of high-quality ripping is right, you can indeed get rid of jitter that way and be fairly sure that the material played back is of the highest quality obtainable. However, neither USB isochronous transfers nor SPDIF are really ideal to get the data to the DAC, as jitter can be introduced there. It would be best to have an asynchronous, error-corrected data path up to the DAC. USB with asynch transfers may provide that, as well as the classic PCI bus. IMHO having the DAC inside the PC is not such a bad idea after all - provided you get the power filtering right (and the shielding if applicable), of course. (It doesn't help when the interface doesn't introduce any jitter but the master clock generates it due to being fed with a dirty supply voltage.)

As for quieting PCs, look no further than SPCR.

 

[mattigol]

Darnit...I wasn't aware that jitter can be introduced anywhere along the signal chain, not just at the CDP. So building a MacMini based system really requires very careful system matching in terms of soundcard and dac.

Let's see what the initial impressions of the HR MicroDAC look like. If it's a good product, I could add it to my current setup now and because of its USB capability worry about a computer-based system later.

M.

 

[Jon L]

Quote:

Originally Posted by sgrossklass It would be best to have an asynchronous, error-corrected data path up to the DAC. USB with asynch transfers may provide that, as well as the classic PCI bus. IMHO having the DAC inside the PC is not such a bad idea after all - provided you get the power filtering right (and the shielding if applicable), of course. (It doesn't help when the interface doesn't introduce any jitter but the master clock generates it due to being fed with a dirty supply voltage.) As for quieting PCs, look no further than SPCR.

Do we know how the PCI bus accomplishes digital data transfer to the soundcard/DAC and whether it's jitter-free, unlike spdif or isosynch USB?

I really like my Lynx PCI card, but I wish I could figure out which PCI pins supply the 12V rail, so I can rig up possibly a 12V SLA battery supply for it..

 

[lucpes]

Quote:

Originally Posted by Jon L I really like my Lynx PCI card, but I wish I could figure out which PCI pins supply the 12V rail, so I can rig up possibly a 12V SLA battery supply for it..

The Lynx card is fed 5V, 12V, -12V from the PCI slot. It already has pretty good filtering (C-L-C on the 12V supplies) so it ain't worth ruining a piece of $700+ ? equipment for such experiments.

 

[thomaspf]

Data transfers over the PCI bus are asynchronous relative to the clock that is driving the DACs or the digital outputs.

Asynchronous transfers do not introduce jitter. In this case the jitter gets introduced when the samples are read and either converted or sned to the digital output from the on board memory buffer via the local crystal.

Cheers

Thomas

 

[Solude]

With a good soundcard, Emu, Lynx etc. the only jitter you'll get is electrical. Data wise they are perfect, but a PC is a PC and electrical noise is present. Solution? Use the optical output and electrical jitter is a non-issue.

Course if you get an Emu 1212m its going to take quite the DAC to beat it in a room with a PC in it. Even the quietest PC will bury the minute differences between a good and great CDP/DAC at a moderate volume.

 

[philodox]

I've done a comparison between the following:

WAV ripped through EAC -> Archos AV320 -> coax digital out -> AOS Flute [DAC/Amp] -> AKG K271 Studio

AND

Original CD -> Eastsound CD-E5 -> coax digital out -> AOS Flute [DAC/Amp] -> AKG K271 Studio

The second setup won hands down. I found that the bass was tighter, there was more air around the instruments and everything was just that much more precise.

I don't normally listen to my CD player in this setup as its internal DAC and analog stage is much better than the Flute and I prefer to use my Dynahi, but before my Dynahi arrived this was the only way I could listen to my CD player. To be truthfull, I did not expect it to make all that much difference, but was I ever suprised.

Another thing to note is that my AV320 as a source [when using digital out] should have significantly less issues that a computer as source.

While I think it is possible to have a very good computer setup, I think a dedicated CD player or transport will win out in the end. Besides, I like the 'quaint' nature of the CD. I find listening to a whole album much more rewarding than 'party shuffle'.

 

[pbirkett]

For me jitter is a contentious issue. I dont doubt it exists, but is it really all that important? Nobody has been able to describe to me what it sounds like, and so I ask the question, does it matter? Only if you are striving for perfection I say.... but perfection doesn't exist.

Theres something for you to think about...

 

[philodox]

Jitter

I can't say for sure if jitter [or lack thereof] was the cause for the drastic improvement in sound quality when using my Eastsount CD-E5 as a transport, but it most definately was there.

 

[Jon L]

Quote:

Originally Posted by philodox I've done a comparison between the following: WAV ripped through EAC -> Archos AV320 -> coax digital out -> AOS Flute [DAC/Amp] AND Original CD -> Eastsound CD-E5 -> coax digital out -> AOS Flute [DAC/Amp] The second setup won hands down. I found that the bass was tighter, there was more air around the instruments and everything was just that much more precise. I don't normally listen to my CD player in this setup as its internal DAC and analog stage is much better than the Flute and I prefer to use my Dynahi, but before my Dynahi arrived this was the only way I could listen to my CD player. To be truthfull, I did not expect it to make all that much difference, but was I ever suprised. Another thing to note is that my AV320 as a source [when using digital out] should have significantly less issues that a computer as source. While I think it is possible to have a very good computer setup, I think a dedicated CD player or transport will win out in the end. Besides, I like the 'quaint' nature of the CD. I find listening to a whole album much more rewarding than 'party shuffle'.

Doesn't Archos AV320 use one jack to double as spdif in and out as well as line in/out?? Even with jitter issue aside, I highly doubt a quality spdif output exists inside Archos. Does it even support bit-perfect spdif out? I'm not surprised at all Eastsound spdif out sounds better in this case.

For a fair comparison, one needs to compare Eastsound to something like Foobar with ASIO (not KS)-->pro quality soundcard coax spdif out (Lynx, etc) with bit-perfect output->DAC. It would be even better to use one of the modded USB-->spdif (better yet I2S) converters. This setup has completely demolished a modded Cary CDP's spdif coax output in my system, which uses similar transport mechanism as Eastsound. Oh, yes, the computer must also be used with high-quality power cord/power conditioner and Platform (like Neuance) just like the CDP.

 

[philodox]

Quote:

Originally Posted by Jon L Doesn't Archos AV320 use one jack to double as spdif in and out as well as line in/out?? Does it even support bit-perfect spdif out? I'm not surprised at all Eastsound spdif out sounds better in this case.

Not sure if it is bit perfect. The jack that the AV320 uses for digital out is the same one that is used for video out... it uses the third conductor that is normally used for the video portion for SPDIF. I have a custom headphile blacksilver cable that I use. Quote:

Originally Posted by Jon L Even with jitter issue aside, I highly doubt a quality spdif output exists inside Archos.

If a bit perfect high quality digital output can exist in my $25 sound card [chaintech av710], I don't see how it is such a big leap to say that it can exist in my mp3 player.

Quote:

Originally Posted by Jon L For a fair comparison, one needs to compare Eastsound to something like Foobar with ASIO (not KS)-->pro quality soundcard coax spdif out (Lynx, etc) with bit-perfect output->DAC. It would be even better to use one of the modded USB-->spdif (better yet I2S) converters. This setup has completely demolished a modded Cary CDP's spdif coax output in my system, which uses similar transport mechanism as Eastsound. Oh, yes, the computer must also be used with high-quality power cord/power conditioner and Platform (like Neuance) just like the CDP.

I would think that most of the issues that you are dicussing here in a computer setup would not be present with the AV320, correct?

Hmmm... I wish I could find out somewhere if it has a bit perfect digital out, there is nothing on their website that I can see.

As for your Cary CDP, I have not heard it, but even if it shares the same transport mechanism as the Eastsound [are you sure about this?], that does not mean that they will sound identical. There are a lot of other things that influence the performance of a transport... most of which you have already mentioned when talking about your computer setup. [power, the digital output, the method by which the mechanism is secured, dampning, etc]