Use a computer based digital source instead of a CD-player

moltosolo · « **on:** 24 Nov 2003, 09:40 pm »

Hi
After some research, I found it is possible to get good sound out of our computer. Some say it's good enough and he no longer need a cd-player.
I am not talking about reading the CD directly from the CD-ROM drive. A better way is using software like EAC to make WMA or APE files, with a good soundcard like M-Audio Delta410, EWX4296, RME 96/8PAD, LynxTwo or even a ProTool HD.
Anyone got some experience with these setups? Good and bad are all welcome.
Thank you all

seti · « **Reply #1 on:** 26 Nov 2003, 10:51 am »

Never done this, but one obstacle is fan noise from the computer. Some hard drives get pretty noisy too. I know my power supply fan sounds like a jet plane, but then it will probably never fail.

I think this is certainly the future. Maybe you could even get room eq, crossover functionality and upsampling on the computer and then go direct into a digital amp. Or a tube DAC out from the computer.

There is probably a good bit of the production side work done on the computer anyway. In theory, nothing wrong with music through a computer.

vpolineni · « **Reply #2 on:** 26 Nov 2003, 02:24 pm »

moltosolo, I run a system similar to what you described.
I had to combat fan issues seti addressed by moving the computer far away and using long runs of cables for my monitor, mouse, and keyboards. I ripped all of my cd's into .wav files using eac and converted them to .ape files for lossless compression using monkey's audio. I play them using the spdif digital out on a M-Audio revolution soundcard. For my digital cable, I use a stereovox HDXV cable (hard to beat at only 75 dollar IMHO) and plug that into a perpetual techonologies p-3a dac. Next year, I'm thinking of buying a p-1a to use their speaker only correction software (SOCS) and room correction software (RCS). I use Ridge Street audio Poiema! interconnects and cables for a Coda-Continuum integrated amplifier and Thiel CS3.6 speakers with some tweaks such as room treatments (eighth nerve). The result? I love the sound i'm getting right now. The room treatments and cables (along with repositioning my speakers) have made my system sound better than ever. One thing I love about using a computer is that I can access any song I want-I don't have to switch cd's to hear a different artist and I can surf the web while listening to some tunes

. You should try using a computer as a transport... it's as good if not better than some transports out there IMHO. hope this helps.

8thnerve · « **Reply #3 on:** 26 Nov 2003, 02:48 pm »

go to www.endpcnoise.com for quiet cases, fans, etc. for your PC.

elnero · « **Reply #4 on:** 26 Nov 2003, 02:52 pm »

An Antec Sonata Quiet case would probably go a long way to solving fan noise issues. I have one here at work sitting right beside me and I can't hear a thing from it. Mind you there is other extraneous noise around but I still barely hear anything until I put my ear almost on the case itself.

Something like an M-Audio Revolution out to a TubeDac might make for a great relatively inexpensive setup. Hmmmm, now that's an interesting idea for my headphone system I'm setting up in the computer room.

Redbone · « **Reply #5 on:** 26 Nov 2003, 03:09 pm »

I have fooled quite a lot with computer music, ie. playing wav and mp3 files from the computer, copying LPs to wav files etc. Mp3 is not a good format as it loses data (bits) on compression, so I stay with wav files.

There is one major isssue that I have never solved on an Intel machine running either Windows or Linux. This has to do with timesharing. To make a long story short, the Operating System pre-empts the music playback, Media player or whatever you're using, every so often to perform houskeeping chores. The break is very short with a high speed CPU, but it is still noticeable to an Audiophile.

In other words, the computer is not designed to dedicate itself to music playback and only music playback, and thus tends to skip or jitter every so often. If you could find/design and install a separate OS dedicated to only playing music, I believe that you could produce digital output that is better than any transport out there. From there ship it to a good DAC and you would have a really top notch digital music player.

Thump553 · « **Reply #6 on:** 26 Nov 2003, 03:12 pm »

http://www.silentpcreview.com/

The source for quiet PCs. You can really quiet a PC down to acceptable levels.

At present I don't have a decent conventional two channel system (I'm educating myself, parceled old system out to kids). My main music source is my computer- M-Audio Revol digital out to Art DI/O to tube headphone amp (AudioValve MrkII) to Sennheiser 600 headphones. I listen to mostly CDs, sometimes SHN or FLAC files (both lossless). I'm pretty happy with this setup-the whole thing cost me $1,000 to $1,500 and its pretty top end sound (at least to my ears).

I have a quiet power supply in my computer and got a really quiet cpu heatsink/fan. I replaced all my case fans (lots) with low noise Panasonic ones and my computer gives an acceptable noise volume - at least for headphone listening. I probably spent $50 to quiet my computer. I could make it much quieter with better planning and more money.

nathanm · « **Reply #7 on:** 26 Nov 2003, 04:04 pm »

I have my computer (10 fans in all) in another room with a cable running to the listening room. It sounds pretty darn good if the MP3 is fairly decent quality. Those file-sharin' crooks out there liked to stick with the default 128k most of the time, sadly enough.

I caved in and installed iTunes and bought a few songs. Not too shabby really, sonically speaking. Worth the money? Nope. Nice distribution model though. The RIAA is up to their same old tricks, it's just that they found a new orifice. If real physical CDs were 10 bucks and iTunes albums 5, then I might consider it, but...

If they want computers to replace the TV set in peoples' homes as some sort of 'media appliance' monstrosity they are gonna have to dispense with the fans entirely IMO. We'll need CPUs that look like Pass Aleph amps! Fans - BAD!!!

Redbone · « **Reply #8 on:** 26 Nov 2003, 04:45 pm »

Not sure what all the fuss is about the fans. I have a home-built computer, Thermaltake Xaser II case with seven fans. Then there are the CPU fan, power supply fans, North Bridge fan, ATI Display card fan, yikes, lots of fans. The only issue I have with fans is dust. The noise is minimal and does affect music playback, IMO.

Mp3 format, even at 256 bit, is not up to the WAV/WMA standard. I have taken a music CD and converted it to Mp3 on my computer. Then take the Mp3 files and convert back to WMA and burn a new CD. It is not as good as the original CD by quite a lot !

The digital output from most modern Audio Cards is quite good when using a good source, like WMA files. Even the analog output is good ! The sound reproduction from a modern PC is astounding, but there is one issue that I mentioned above that really bothers me and I am wondering why other folks don't mention it.

When listening to the signal (output, whether digital or analog) being produced by a PC, I can always detect slight clicks, skips, stutters or jitter, whatever you want to call it. It is not a big deal, but it is enough to prevent me from getting completly lost in the music. It is caused by the flow of data being interrupted, very quickly but on a cyclical basis, by the Operating System of the computer, particulaly when using a PCI bus sound card.

I have greatly reduced the problem by using on-board sound from the Gigabyte motherboard, as this bypasses the PCI bus to a degree. A really fast CPU, P4 3.0, and really fast memory helps, as well as HT which allows two processes to run concurrently. But in the end there is still a low level of jitter that shows up sonically as clicks. The music flow and tempo is not quite right 100% of time, but is spot on for most of it. The Windows OS simply cannot dedicate itself to uniterrupted production of Music, digital or analog. Linux has the same problem, to a greater or lesser degree, depending on the configuration.

The sound produced by the PC is excellent, in some ways better than the best CD players that I have heard. But the artifacts introduced by the OS are enough to keep me from truly enjoying it. Just my rather lengthy two cents.

nathanm · « **Reply #9 on:** 26 Nov 2003, 06:30 pm »

I think Winamp does have a preference for processor priority level. I am using NT 4.0 w\dual processors and haven't experienced any clicks or noises. I know on an older machine I had MP3 playback could be hosed by simply scrolling a window! Sheesh!

I suppose fan noise is subjective to a degree, but I think anyone would feel my fan noise is definitely "maximal"!

Redbone · « **Reply #10 on:** 26 Nov 2003, 07:10 pm »

Winamp allows you to set the priority of the Winamp executable relative to other executables, ie. Internet Explorer. I am talking about the actual operating system itself, Windows, pre-empting the machine cycles. This will happen regardless of how many physical or virtual processors you have, or which Windows OS you are using. It is more of an issue with older, slower computers, and is worse on older versions of windows. But it still occurs with XP or NT, even with dual processors.

PhilNYC · « **Reply #11 on:** 26 Nov 2003, 07:56 pm »

I've not spent much time trying to use my computer as a digital source, but I've spoken to a few people who have. The biggest issue described to me (asides from the timeshare issue already raised) is that the inside of a PC is a huge EMI/RFI mess...and digital source happens to be the component most negatively impacted by EMI/RFI. If there was a way to take an external hard drive with a direct digital-out, that would be great....

Redbone · « **Reply #12 on:** 27 Nov 2003, 05:11 pm »

The EMI/RFI interference is an excellent point. For analog output it is probably a factor. For digital output I don't think it will have any effect. The binary output consists of 0s and 1s. I don't believe that a 0 will be corrupted to a 1 or a 1 to 0. If that were the case, the machine would have other issues as well, like corrupted memory and crashing programs. The analog signal is much more sensitive to external fields, but I believe that the digital output is clean.

PhilNYC · « **Reply #13 on:** 27 Nov 2003, 05:35 pm »

Quote from: Redbone

The EMI/RFI interference is an excellent point. For analog output it is probably a factor. For digital output I don't think it will have any effect. The binary output consists of 0s and 1s. I don't believe that a 0 will be corrupted to a 1 or a 1 to 0. If that were the case, the machine would have other issues as well, like corrupted memory and crashing programs. The analog signal is much more sensitive to external fields, but I believe that the digital output is clean.

This comment is the basis of absolutely *huge* debate among audiophiles and digital audio designers. You could say the exact same thing about digital cables, transports, etc...but the fact still remains that all those parts will make an audible difference in a high end system. You see lots of people on this and other audiophile forums discuss the benefits of ERS cloth on DACs; digital component designers going to length to separate power supplies (large source of EMI) from the DAC; etc. Jitter is a real phenomenon that flies in the face of the "bits is bits" argument. I don't mean to be a downer on the above comment...but since it's already a topic that starts flame wars and the like, I thought I'd just get us underway...!

Redbone · « **Reply #14 on:** 28 Nov 2003, 02:31 pm »

I actually thought quite a lot about this Wednesday night. Dangerous, I know, but I didn't hurt myself. As far as the DAC goes, all bets are off because it generates an analog output. Shielding may have value here. As far as the digital source, whether a computer or a transport, there is some credence to the interference hypothesis.

I am not knowledgeable enough at a harware level to give expert testimony but I do know that both the hard drives and RAM (memory) use error checking and recovery algorithms to prevent data loss and corruption. The same problems may well (and probably do) occur with a digital audio feed. Similar algorithms could be used to insure data integrity. But now we get into the original problem that I was concerned with, uniterrupted data flow.

At some point, for true audiophile quality sound, the digital data has to flow or stream unbuffered and uninterrupted, without error checking etc. Now shielding may be (very) important. Putting aside the issue of OS problems, I have to now agree that the EMI/RFI interference is an issue, even with digital output, on a computer or any other digital audio source. Add to that the inherent problems with timesharing and I say that a modern computer is really not an audiophile quality sound source. Which is what my ears told me in about 5 minutes to begin with.

PhilNYC · « **Reply #15 on:** 28 Nov 2003, 02:49 pm »

FYI - there's an email group on Yahoo that is dedicated solely to using PCs as a digital source. Check it out:

http://groups.yahoo.com/group/PAMS/

JackStraw · « **Reply #16 on:** 28 Nov 2003, 03:38 pm »

Quote from: Redbone

I actually thought quite a lot about this Wednesday night. Dangerous, I know, but I didn't hurt myself. As far as the DAC goes, all bets are off because it generates an analog output. Shielding may have value here. As far as the digital source, whether a computer or a transport, there is some credence to the interference hypothesis.

For further mental exercise, consider the USB output of the PC run to a device like the M-Audio Sonica Theater, http://www.m-audio.net/products/consumer/sonica-theater.php. I wonder whether the USB signal is sensitive to sheilding... I certainly haven't seen audiophile grade USB cables (yet).

tmd · « **Reply #17 on:** 30 Nov 2003, 10:20 pm »

I read somewhere a while back that more modern CD players come with DACs that have onboard buffers. In my ignorance of such things, I would imagine that this would remove any problems with digital delivery as the buffer would persist until it got all the data and deliver it to the DAC without any jitter problems.
Anyone familiar with this?