I'm running an Alpine 9833. It has a regulated 1 Bit DAC, whatever regulated means. I've got no qualms with the deck and think it sound excellent. Through more recent surfing/reading I've been gathering more knowledge and Burr-Brown, 24 bit DACs, etc have come to my attention.

I've never had a chance to compare my deck to a deck with a Burr-Brown or comparable converter. How big a difference would there be? I'm not really looking to upgrade, this question comes more out of curiosity at this point.

 

I asked this question to an engineer at Alpine as a matter of fact. He was quite insistent that the biggest concern when comparing DACs was the S/N ratio and noise floor. Different designs have different general limitations (Jim may be able to go into the what and how of things, I can't) as fare as how good a S/N ratio can be achieved and what the noise floor is like.
1-Bit DAC - 80db
1-Bit Regulated DAC - 85db
Multi-Bit DAC (4 Bit, 8 Bit) - 90db
Sign Magnitude DAC (Like the Burr-Brown) - 100-120db
That Alpine is really pushing the 85db limit. Burr-Browns tend to be at the high end of the 100-120db range, but there are other types of Sign-Magnitude DACs.
Now, does all this really mean anything? Some would say the differences are inaudible. I think that they are audible, barely, but most of the time there are other things going on that help cover up for a minimal noise floor. The only time I really notices the difference in the noise floor is if I'm really cranking some classical, after I settle in I can pickup on it as the zero bit muting kicks in and out. Most zero bit muting circuits only mute after what ever IC has the DAC which usually also includes the DSP, servo control, RF amp, APC control, ... So it only mutes the CD section and any noise leftover is from the rest of the audio path (this is where thing like STAR grounding come into play). You should also note, if you're going to try some listening, that some CDs are just bad recordings and have a noise floor right there to decode and play back. Best way is pick one CD with a lot of quiet stuff and loud stuff (like classical) and compare it on a lot of different CD players. If it seems to have a high noise floor on all of them, it just the CD. I wouldn't worry about it though, It's a drop in the bucket.
Now this is where Jim comes in and proves me wrong.....

 

I'm not aware of any S/N ratio issues between different types of DACs. My understanding is that any DAC is clean enough to not pose any S/N limitations on the signal. The S/N ratio with a cd transport is always based on the limitations of the 16 bit media. This is why you can have such drastically better S/N ratios with DVD-A and SACD... because the resolution allows it. I don't think that the DACs in those devices are really any better. I'm more inclined to think that the S/N ratio in head units is limited by the cheap op-amp pre-amp stages, as well as the overwhelming levels of DSP that gets done to the digital signal before it gets to the DACs.

The main difference between a 24 bit DAC like a Burr Brown and a more common 1 bit is the method in which it converts the digital stream. I had a very clear understanding of this back when I was in college, but I've had a lot of time to let that knowledge get displaced as my brain filled up with less important stuff... but my recollection is that a 24 bit DAC takes an entire 24 bit word, and converts it to an analog signal as a whole. This gives more resolution (and now that I think about it, maybe better S/N ratio) to the analog signal than a 20 bit DAC or a 16 bit DAC, because you have a more precise representation... though the way you get 24 bits from a 16 bit signal is to add 8 "Zero" bits on the end of the original 16, so you're still not actually gaining a hell of a lot.

Now is where it gets fuzzy for me. A 1 bit DAC works in a completely different way. A 1 bit DAC takes in one bit at a time, but I don't remember the process it goes through to convert it to the analog signal. I do know that 1 bit DACs are cheaper and easier to impliment, which is why they get used much more often than 20 or 24 bit DACs. I'm not aware of a 1 bit DAC having a negative impact on S/N ratio, at least not for a 16 bit signal.

But, what does all that crap mean for sound quality? Not much. If it was possible to do an A/B double-blind test between two devices that were identical except for their DACs, I'd be surprised if any of us could actually hear a difference. Once you add in all the other differences between two different devices, the DAC becomes even less important to me. As far as I'm concerned, the "burr brown" DAC, along with any other high-bit DAC, has become a good marketing device more than anything else. Tell a guy it sounds better, and he'll think it does.

Once you have perfect acoustics in your car, with flawless speakers, and a full digital transport that's not converted to analog until right before the amplification stage (pure class A of course), then I'd start to worry about the type of DAC your head unit has.

 

I'm willing to be that this is fairly accurate. A blind test would be fun to try out but there's no good way of doing it because it's hard to find comparable units that only differ in what type of DAC they use. I’m guessing it is more marketing but at the same rate it’s somewhat expected for higher end units to have better DAC converters.

Thanks for the info Jim & NEEDAZ. If anyone has anything else to add (mean, etc?) feel free to post it even if it is just hearsay.

 

Hello, maybe you guys can help. I have had the same questions about the Burr Brown DACS. I am trying to set up a great car audio system. I am looking at getting a Nakamichi DAC-111. It only has 18 Bit DACs but there is 4 of them. So my question is, is four, 18bit, better than two 24 bit, say like the McIntosh? Its been driving me crazy, I just want great, pure sound. I know I have heard many of the Alpines and they do sound good, But I can hear "empty space" Kinda like the difference between CD and Vinyl. many of my friends say I crazy but I can hear subtle nuances that many of them cannot. Another question refers back to the Nak-111, It only has a left and right output, How can I split the signal to 4 ch. without adding line noise and getting too much drop in voltage?
Any help would be greatly appreciated!!

 

Hi to everyone,

I'm in the process of gathering all the current head units that employ the Burr-Brown in their DAC section and so far I have found Alpine (iDA X200, iDA X100), JVC (KD-PDR80, KD-APD89, KD-BT1) and the Sony (MEX-DV2000).

Before anything else, in the interest of edification, to posit that whatever internal dac design or brand does not make any audible difference, hence, doesn't matter is to say, essentially, that all cd players sound the same. This is easily verifiable. Hold everything else constant except the digital part if you wish and I guarantee you, there is a reason why BB has built a reputation for good sound. You can say BB and Analog Devices (AD) is to DACs as Mercedes-Benz and BMW is to cars. The quality and degree of refinement is simply top-notch and in BB/AD's case, definitely audible.

The best part is, the head units I mentioned are all affordable. The Sony, for instance, even plays DVDs, SACDs, has 5.1 capability (not that you need it), is iPod-ready, etc. all for $200.

I hate to say it, but pretty much everything in the signal chain, from how the music was recorded to how your cd was burned to how your cd was optically read by your player to how the digital stream was converted back to analog waves to how these waves are amplified by your preamp-to-amp section to how the amplified signal is transmitted by your speakers cables to how your speakers and surroundings finally reproduce the music you love, individually and collectively influence the end-result.

For some, it is life-long quest. For others, happiness can be a decision. Either way, enjoy music to the fullest. It is one source of happiness no one can take away from you and something that brings out the good in all of us.