The best approach would be to convert your files to CD quality 16bit /44. The cables I don't think will impact much, as optical can carry high rez 24/192, Digital Coax 24/96 and USB will carry CD quality 16/44.
Most nice DACs are 24 bit and up-sample. They are made for improving CD sound. I don't really know what the up-sampling does, if it smoothes out the signal or what.
For 300 bucks you can get a 120 giga byte i-pod and then upgrade all your music to CD quality. MP3 is low resolution, that is primary factor in low quality sound. You can find a better DAC and then upgrade to CD quality files and then should move you pretty far along.
For mp3s, I'd just use the mini's optical out and skip the DAC.
I think you would notice a substantial increase in quality, even of your 128 kg/s mp3's, if you bypass the dac on your sound card and use a reasonably priced external DAC. I haven't heard the Blue Circle but it's from a well-regarded company and the strictly utilitarian design of it is appealing. I use a Valab DAC, available for $200 on ebay, between a MacBook Pro and a Nuforce Icon amp and it sounds quite a bit better than going analog from the MacBook to an amp. Even the internal DAC on the Icon is an improvement over the sound card in the laptop with mp3 files.
To Scottlanterman's suggestion about converting your music and using an iPod, you'd have to re-rip everything at higher resolution, not just convert your existing files, assuming you even have the high-res originals. In addition, unless you have a Wadia iPod dock with digital output, you'd be using the DAC and amp inside the iPod and that might not be much of an improvement over what you already have.
The newer iPods have much better DACs now, but Sfar is right, I use a Wadia 170i out to a Peachtree Nova. It sounds really good, but it is about a $1,500 set up and all my stuff is lossless CD quality rips on an old iPod.
That USB Thingee might just be the thing for you, it looks it is worth a try. I would still re-rip your favourite music lossless and do some comparisons to the low rez MP3 files to see if you get more enjoyment out of it.
A better long term investment might one of the Camebridge Dac Magics on sale for about $350 on the site. This is a well reviewed component that will hold its value and should do a very good good with whatever digital system you end up with.
Best of luck.
Acura1947 You should check out Scott-nixon.com. He makes both solid state and tube Dacs. I have the tube Dac with coaxial out but he also makes it in USB. Just last week there was one with both toslink and coaxial jacks. Scott also has an extensive background on what you are doing. Visit the web site given above and give him a call. Every now and then one shows up here on Audiogon but they don't last long. The pricing is great but the performance is even better.
If you are using a PC I suggest you upgrade your sound card to a Creative Labs Audigy. If you are using computer speakers that is. The power is clean and the distortion is very low. To me the sound cards built in most computers don't sound very good. And when you send sounds from your computer to your main system via a DAC you will be pleasantly surprised also. You will get a quieter background and lower distortion. Visit his site and see what he has to offer.
FWIW... From my experience, most definitely, a DAC will improve your MP3 playback. It should get rid of lots of harshness. I'd get a glass toslink cable and connect it out of your computer.
If you're using a Mac then it's even easier. Set AudioMidi to 25/96 and you're good to go. Mac's however, outputs through "mini-toslink". You can get a Vandenhul Optocoupler II for $100 (as good as it gets for optical cables get from my understanding) with a mini on one end and a regular toslink jack on other end. Or if you need a longer one, Parts Express has a 12ft glass one for $65.
Or, if it's MP3s anyways, you can simply get an Airport Express and stream your music. It has a DAC in it, and from my experience with a NAD 325bee, it sounded noticeable better through the AEx then a Y-cable straight from computer or ipod. It's $50-90 (look on Craigslist) and you can always return it...
This is your cheapest route.
For $300-350 used you can probably get something very nice these days. I'd go with a tubed DAC if I were you, so you could tube roll later (change sound for cheap) and "color" the MP3 sound. I'd probably look for these ones, as you could re-sell them easily if you don't like it:
-MDHT Paradisea+ (older version)
-Channel Islands vDAC (or something like that)
Hear lots about this one on another forum, but never tried it:
-VALAB Dac (sold on ebay for $200 new).
-the DAC Magic mentioned also gets a lot of mention in other forums as well. No experience.
I really like my Monarchy M24, it's a tubed DAC with a separate tubed linestage/preamp (2 power supplies), but it's $700-800.
I've been very curious about the Paradisea and Valab though.
You might want to lurk around this forum:
People on Audiogon seem to think MP3s are an abomination.
Also try to get 320 kbps files at least... try mininova.
And I don't think there is any point in converting MP3 files into large "CD Quality"-full bit-rate files, other than wasting storage space. As far as I know, once the bits are compressed and gone, there is no way to restore them.
Good luck. Send me a PM if you have any questions.
If you listen to mp3, an external DAC or Blue Circle USB thingy will be an absolute overkill and a waste of money! Such things are for lossless formats, not for compressed one. On the other hand, if you have no access to lossless files (which seems strange to me), I can understand your desire to get the best out of mp3 files. I was myself in the same situation 5 years ago. Here's my advice to you: find an old Sony DVD player DVP-NS330 or newer models of the same series. I have NS330 and I can tell you that the quality of this Sony's inbuilt mp3-decoder is magical. I don't know what this Sony does to mp3, how it converts it to pcm and how it treats it further before it finally comes out of its analog outputs, but the result is just stunning! In the true blind tests, I and my friend compared the audio-cd tracks, played by cd-player NAD C521BEE against the same mp3 files (lame, 320 kbit/s) played by Sony DVD player DVP-NS330, and in 50-70% cases we couldn't tell the difference! The amplifier used was NAD C320BEE and the speakers were Acoustic Energy Aegist Evo 3. This Sony just refines mp3 sound somehow, making it sound rich, full-bodied, etc. The drawback was that this dvd-player could read mp3 from a dvd media, only from a cd.
When tried to play mp3 files through my current $700 DAC, $1000 preamp and the same NAD amp, it sounded worse than that Sony NS330.
Another curious thing about this NS330 is that it played Audio-CDs noticeably worse than mp3 made from the same CDs! I am not kidding, we also confirmed it, together with my friend, in blind tests.
wow thanks for all the feedback. I just turned 21 so I still got a lot to learn. Many have asked why I dont use lossless format for my music. The thing is I get most of my music off the internet and thus they come in mp3 (192kb/s normally). For the amount of music I have on my computer, over 100 gigs, it would not have enough space to accomodate lossless music. On another note, some of you have said a DAC will do good while others have said that it will do nothing. Do you think a logitech duet transporter instead of a DAC would be a better and more sure to sound better? I have a phase PC1.1 II speakers and a pioneer elite receiver which I am too also replace with a integrated amplifier like NAD or cambridge audio 500 series. nothing too fancy. anyway thanks again for all your help. god bless.
The above sentence in my earlier post should read The drawback was that this dvd-player could NOT read mp3 from a dvd media, only from a cd. Sorry, my mistake.
I can't believe you cannot find lossless in the internet! You must be looking at wrong places. I have an unlimited internet at the office and even though the bandwidth allocated to me is small (3-7 Kb/sec, i.e. 24-56 kbit/sec), by downloading day and night I get more lossless hi-quality exclusive hard-to-get music than I can physically listen to at home!
If you still insist on mp3, try to understand that mp3 playback consists of two stages: First, mp3 signal must be decoded into raw pcm. Secondly, this pcm is then converted to analog signal by a DAC. The DAC does not decode from mp3 to pcm. So, if the decoder algorithm in your source is lousy (and they do differ in quality!), DAC will not help you.
Forget about mp3! Its a thing of the past. Also, if you have 100 GB of mp3 files in your computer, and if they are normally, like you said, 192 kbits/s, then you have music to plan non-stop for 50.5 days (Ive just calculated). If you listen to music (non-stop) only 3 hours per day, it means you need 404 days to listen to your collection at least once. I am sure there are some albums which you listen to at least 2-3 times, right? What I am trying to say is that considering the availability of music in the internet, its useless to collect music as we did in the past. What people lack nowadays is free time (to listen to music), the unavailability of music itself is not a problem. But collecting music steals our time. Just my two kopecks!
Couple of things you may not be clear on.
The MP3 or any other compressed format that you have collected has lost some of the musical magic. However... you may not have the equipment (receiver and speakers... or pre amp, power amp and speakers) to hear it. (some will tell you that the high bit rate rips sound the same as the wav file... but disk space is cheap these days so... why compress) The higher the resolution of these pieces down the chain.... the worse your mp3 will sound. Try comparing the same music ripped lossless (FLAC is a good soln) to your mp3 or whatever rip you currently listen to now. If you hear the difference... you get to decide on the digital format. If you don't hear the difference you can upgrade the digital to analog conversion hardware in the system. (The software music player can also make a big difference as well... beyond just making the sound come out of the speakers).
In general, moving the conversion of bits to analog signal outside of the PC is a cost effective and more musical solution and so it would be better... (higher musical resolution then what you have now). But you have an extra box and power supply plus cables to deal with. Alternatively, a better sound card will keep the electronics in the PC and allow you to use headphones or output to your receiver when you want. At some price point the outboard DAC and amplifier surpasses the sound card with dac and amplifier solution in musicality.
You probably upgrade the PC sooner then your music system so an outboard DAC and amplifier makes a lot of sense relative to a audio card. Converting the digital signal to analog in the PC happens in an electrically noisy environment and you can only do so much.
Your AV receiver (not a stereo reciever) has built in DACS... so you could use a USB converter (Hagerman or many others) to drive the Receiver DAC or any number of non USB DACS on the market, new or used. (Make sure your current player software does this)
You could also get a USB DAC with built in amplifier which will give you two channels for input into your receivers Analog section (ditto about the player software).
How the DAC handles jitter and the amplification stage make a difference in musicality at these two stages. (eg some DACs use tubes and not transistors to amplify the sound for the receiver.
Keep in mind that musical resolution, once lost does not come back... So, you hear the weakest link in your chain. Coming up with a strategy that builds a system to your budget in time is part of the hobby.
But.... having my niece who is also in college listen to all of the differences on my good rig... does not change her preference for quick and easy low res mp3's on her PC and a pair of cheap headphones. Ah well!