Hi,

I'm currently trying to figure out how to build a good HiFi solution based on my PC.

As far as I've realized so far is the the sampling rate of a normal soundcard (48khz) and a normal FLAC file (44,1khz) is that you get a problem if you choose to use the soundcard. Not only that, but also that there is a transfer with distortion from the soundcard to the Receiver. So, basically, I figured out that using a DAC with a Sync on which allows 44.1khz is the way to go.

So far, so good.

Now I just have to figure what to look for when buying a DAC. Assuming that my HiFi solution (excluding PC) will be an investment at about 4000$, what is a reasonable solution for the DAC? Are they different?

I've only looked briefly so far and seen that a DAC can cost from 50$ to 2000$, but what is the difference?

Please enlighten me here, and if (judging from my budget) you can give me some advice on an actual unit I'd be delighted.

Thank you!

Firstly, not all PC soundcards can't handle 44.1kHz natively. For example, the super-cheap Chaintech AV710 can handle 44.1kHz without resampling. There are many, many cards like this. Unfortunately the ubiquitous Creative cars aren't among them.

Choosing a DAC is a complicated business. There is one thing to bear in mind when buying digital equipment - expensive doesn't neccessarily mean good, and cheap doesn't mean bad. The vast majority of external DACs use a tiny little IC for conversion - the hard work. These ICs cost well under ten bucks each - even for really good ones. The biggest single issue with DACs apart from the quality of the integrated circuit they use is the way they clock the signal. If they do it wrong then Jitter becomes a problem. Jitter introduces distortion and noise into the output analog signal.

This topic has been discussed extensively here on HA. A search for Jitter or just DAC should pick up some really good threads.

As I have advised when asked about receivers, the cheapest way to get a decent 2 channel dac may be to get a slightly obsolete home theater one.

A few years ago, about when DTS started coming out in HT gear, I got a Denon Dolby Digital decoder (also does 2 channel) with 2 optical, 2 coax, 1 RF (for laserdisc), 1x 6-way analog input, and 1 optical and 6-way analog out for ~$80 new (but previous year model). It is essentially a preamp with mostly digital inputs.

Similar deals should be available today if you skip the side channels or whatever is the hot new feature this year.

One tip I would pass along. Make sure you take a look at semi-pro and pro models, not just consumer "HiFi" devices. Most pro gear is much better value than consumer stuff, but has the downside that it's usually butt-ugly. Examples of well-regarded semi-pro & pro DACs are: M-Audio SuperDAC, Lucid DA9624, Benchmark DAC1. The DAC1 in particular is generally regarded as pretty much state-of-the-art, and costs under $1000. You can pay 20 times that for a "HiFi" DAC that sounds no better (but admittedly looks much nicer).

Another thing to consider is that modern semi-pro and pro soundcards such as the DAL Card Deluxe and Lynx Two have stunningly good DACs and output stages; more than good enough for any home HiFi setup. Even the humble M-Audio Audiophile 2496 is arguably good enough.

Thank you very much, I recently read about the DAC 1 and they praised it as well. Locally though it seems to be more 1500$ than 1000$. Maybe it's possible to get around that, I wouldn't know.

However, I'm a novice anyway so I have to know about 2 more things here.

1. Say I play a FLAC file in Foobar, what actually happens along the way here if I choose the DAC 1. I'm trying to understand the technique!

Is Foobar converting the FLAC file to Wave information which is sent on to the DAC? Or is it so that the DAC player needs to be able to interpret the FLAC file?

I figure the software on the computer handles the decoding and make it to a Wave file.

2. From what I've heard, these DACs are not depending on drivers in the computer. Meaning if I chose to Run Windows/BeOS/FreeBSD or whatever, it'll work no matter what? Am I correct or wrong?

Thank you BTW I appreciate all this help.

Foobar decodes the FLAC and does any processing you specify. It sends the signal to the soundcard. The preferred method for transmission is ASIO. The soundcard produces the SPDIF digital output. Even if you use a DAC you need a decent sound card. The E-MU 0404 is a good one.

How can that be? I mean using SPDIF is not as good as using USB as far as I know and the DAC 1 for instance uses USB. That's where I get a bit confused. Where does the soundcard get involved? I thought the DAC did what the soundcard is doing (just that you can get it to be effected of a lot less distortion being external).

If you mean the Benchmark DAC-1, that doesn't use USB.

You're absolutely correct. My mistake. I confused it with Apogee Mini-DAC. But why would someone wanna go for SPDIF which is clearly inferior to USB in this case? The signal can get error correction along the way etc etc...

Okey I guess all this means I have to rephrase my question. can anyone point me to a DAC which uses USB?

As a means of transmission of digital audio, USB most certainly is NOT superior to SPDIF. If you restrict yourself to DACs that accept USB, you're ignoring many very fine DACs. Basically, the only DACs you'll find that have USB inputs are USB versions of soundcards (for example the M-Audio Audiophile USB). Using a simple PCI soundcard with a non-resampling SPDIF output would be my choice of getting a digital audio feed from a PC into a DAC.

PS. You mention that the Benchmark DAC 1 is more like $1500 in your area. Where do you live? If you're in the US, you can order one direct from Benchmark for $975.

Ask for substantiations of why anyone should spend so much on a DAC of that cost.

An E-MU 1212M, a PCI card ADC and DAC at just $200, almost pegs the limits of possible performance considering the inherant thermal noise of circuitry used in room temperature conditions. There is not justification for the very expensive DACs that I see often suggested, at least not in terms of performance(cosmetics and status are a different issue) vs. lower cost alternatives.

If you want a very powerful(and high quality) stand alone DAC that is low in cost, refer to the Behringer SCR2496. It uses the same DACs as the M-Audio SuperDAC, btw, is much more powerful/versatile ---- and lower in cost.

-Chris

SPDIF is not the perfect transmission mechanism they say. But the Benchmark DAC-1 and other DACs around this price (Bel Canto DAC 2 is the main competitor I think) have very aggressive jitter reduction to the extent of making the SPDIF source irrelevant in the view of many owners.

I live in Sweden, taxes here is a bummer...

I'm still confused here. What I'm trying to understand is why would it have to pass the soundcard? And how can one-way SPDIF be better than 2way USB with error correction? I can see that SPDIF has been the way to go before (for some reasons?) but I simply cannot understand how it can continue to be that way.

But from what you guys are telling me, someone doing this would use a soundcard (where distortion arise) sending it through SPDIF (fibre) where more distortion arise, and then try to correct that distortion with a good DAC? How can that be preferred method when it could be sending data through USB straight to DAC and then on to amplifier?

Maybe I'm missing something here or it is a fact that those making the equipment have to get a clue?

Distortion in spdif has an effect, but it is certainly correctable - unlike distortion in an analog signal.

Haicube,

First - it's good that you want to read and understand more before spending your money!

Right - the FLAC file contains a losslessly compressed representation of the original digital audio. The FLAC decompressor in foobar will decompress this losslessly to the original 2 times 44100 16 bit samples per second. If you have DSP enabled, it will apply that too - if you don't, the output from foobar will be bit perfect.

Foobar passes this along to whatever device you have specified. As has been mentioned, some combinations of sound card, drive, and windows Kmixer (which can, but doesn't have to, sit between foobar and the sound card driver) will change the audio by internal resampling - while other sound cards will happily take the bits from foobar, and not change them at all.

A good sound card with a digital audio output is going to take the exact bits of audio information that foobar passed to it's drivers, and pass them out of the SPDIF (that's coaxial - electrical) or TOSLINK (that's optical) output unchanged. Just like the bits don't get changed on their way from your HDD to the processor, so the buts aren't going to get changed on their way through a good sound card.

SPDIF is a digital interface. It sends bits. The issue with SPDIF is that it doesn't have a separate clock - the clock is recovered from the edges of the data bits - that no problem in theory, but not great in practice if you're not careful. The kind of devices you're talking about decouple their internal clock from the recovered SPDIF clock so carefully and thoroughly that it's largely irrelevant.

In any working system there are no data errors over SPDIF. If there are errors, the system has failed, and the results are not subtle - you'll pops, crackles, even bangs. Just as you would expect if random bits of audio data were being corrupted.

So, by picking good software and equipment, and by keeping unnecessary and unwanted processing out of the signal chain, the DAC is going to receive exactly the bits that are represented in the original FLAC file.

The quality of the sound is (or should be) due to what the DAB does with this data - but the data itself will arrive perfectly intact and unaltered. This is trivial to verify - just record the digital signal back into the PC and compare it with the original audio data - it should be a bit perfect copy. If it's not, something has gone wrong.

Hope this clarifies things.

Cheers,
David.

I've been following this thread with great interest - as I too am looking at creating a decent home-made hard-disk player.

One question I still have though, is what would one recommend as a decent cheap soundcard that outputs truly unaltered data through it's digital out?

I'd recommend this thread: http://www.hydrogenaudio.org/forums/index....c=11725&hl=
or one of the many others on this topic.