Measurable differences in DAC Chips?

Discussion in 'Audio Hardware' started by mixedupfiles, Jan 13, 2012.

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  1. mixedupfiles

    mixedupfiles Forum Resident Thread Starter

    Location:
    Austin, TX, USA
    After participating in the SHM Magic thread, and enjoying the Jitter thread that crapfrom the past started, I'd like to move on to the next component in the chain: The DAC chip.

    My profession has given me great faith in CD media itself and the ability of even moderate systems (within spec, of course) to read and transmit digital data properly. With that in mind, I have always assumed that any audible differences between CD players would have to be attributed to the analog side. (If you don't share that same assumption, my question on DACs is probably still valid. For the sake of the conversation, if you want to picture the bitstream as coming from a gold-foil, super-clear-plastic, green marker traced CD over a golden spdif rca cable, then picture it that way.)

    The question that lingers for me is: Has anyone ever done any testing to determine how different DAC chips sound? I concede that a DAC Magic might sound different than a Benchmark DAC-1 which might sound different than a Bel Canto, but how much of that is attributed to the analog side, and how much is the chip itself? To ask another way, has anyone ever done any extensive testing on whether or not a Cirrus Logic DAC sounds substantialy different than a Burr Brown, or a Wolfson, or any of the other chips? Personally, I just haven't had enough exposure to enough equipment to be able to say one way or the other. I'm definitely interested in the topic, though. I do remember reading somewhere (possibly the Audio Critic) that the Benchmark DAC-1 measures near perfect but I don't know if the same can be said for other DACs that use the same chip.
     
  2. SACDLover

    SACDLover Forum Resident

    Different DAC will give different sound, even with same analogue stage.
     
  3. kevinsinnott

    kevinsinnott Forum Coffeeologist

    Location:
    Chicago, IL USA
    Lampzator

    http://lampizator.eu/

    You may find this site interesting. He claims to hear major differences in DAC chips. I think his favorite was a vintage Philips chips, but he has since moved on to later chips from Wolfson and Sabre. Fun reading, as his writing style is as refreshing as his perspective.
     
  4. McGruder

    McGruder Eternal Musicphile

    Location:
    Maryland
    You say you have "great faith in CD media itself and the ability of even moderate systems (within spec, of course) to read and transmit digital data properly", but that isn't the job of the DAC at all.

    It seems quite reasonable to me that DAC chips may sound different to certain people, given that they are essentially algorithms and software for transforming bits into signal. Toss in more algorithms for digital filters and you get more differences. The amount of improvement in DACs has been tremendous, especially in the last 8-10 years. Why is this controversial?
     
  5. mixedupfiles

    mixedupfiles Forum Resident Thread Starter

    Location:
    Austin, TX, USA
    I was just saying that to get past the discussion of media and concentrate on the dac chip itself. In other words, for the sake of discussing DAC chips only, let's assume that CD media is capable of supplying the DAC chip the proper data.
     
  6. mixedupfiles

    mixedupfiles Forum Resident Thread Starter

    Location:
    Austin, TX, USA
    ... and I'm not saying it's controversial. I'm just saying that I don't know and I've never read any studies or A/B tests on the subject. What I have read is that this dac chip has a wider soundstage, or that that dac chip sounds airier. I don't want a dac to do any of those things. I just want it to be very, very accurate.
     
  7. Erik Tracy

    Erik Tracy Meet me at the Green Dragon for an ale

    Location:
    San Diego, CA, USA
    And the design, layout, and selection of the components used for the analog output stage will also contribute to the resultant sound.

    So, I don't get the intense isolated scrutiny that DACs get when considering a player - everything matters or - nothing does.
     
  8. kevintomb

    kevintomb Forum Resident

    I think ( hopefully I understand ) that the op is simply asking about just the DAC section as that is all he wants the thread to be about. Not saying the rest matters not at all, but hes singling out one part to discuss.
     
  9. Erik Tracy

    Erik Tracy Meet me at the Green Dragon for an ale

    Location:
    San Diego, CA, USA
    I may have read the OP's wrong then, but it read to me as if he wanted to know how different DAC 'chips' sounded - so how would that be possible unless every other variable in such an 'experiment' were controlled?

    And I don't think there is any valid way to test this given commercial players or external "DACS" (inclusive of analog output stages)- not only do different OEMs use different DAC 'chips', but everything else would be different as well.
     
  10. winopener

    winopener Forum Resident

    Read several pages, and nearly all the tweaks he does are power supply. Very important.
     
  11. McGruder

    McGruder Eternal Musicphile

    Location:
    Maryland
    I can't think of a way to test them or measure them while keeping all other things held constant. It might be better to learn a little about DAC design, and to listen to implementations using the DAC design, and make your own conclusions about what it sounds like: Oversampling DACs vs NOS (non-oversampling) or Synchronous (SRC) vs Asynchronous (ASRC) sample rate conversion for example. People that are really into evaluating the way DACs sound get acquainted with these topics on some level and listen to the gear. Some of them end up lining up behind a particular DAC design as one of the qualities they look for in a digital player or DAC.
     
  12. riverrat

    riverrat Forum Resident

    Location:
    Oregon
    If you've got a lot of time on your hands, spend some of it over on head.fi sifting through the various threads discussing the sonics of different DACs, including the chips themselves, ad infinitum..
     
  13. McGruder

    McGruder Eternal Musicphile

    Location:
    Maryland
    Hey, if you're not motivated or interested enough to dig in, then you basically remain stagnant and regurgitate the opinions of others. But I understand the predicament of those with "no time" in our fast paced cell phone happy world :sigh: What would you suggest, other than throwing your arms up and lamenting about your busy life??
     
  14. mixedupfiles

    mixedupfiles Forum Resident Thread Starter

    Location:
    Austin, TX, USA
    That's correct. In many of the forums that I lurk, I've gathered that many people assume that a box that contains a wolfson/sabre/analog devices chip must sound better than a box that contains a cirrus logic chip, but with so many variables I'm wondering how much can be attributed to the actual chip? I don't think I've ever read any reports on the subject.

    (For the sake of this conversation a "box" can be a CD player, an AVR, a media player, or an external DAC.)

    Like I mentioned before, I wouldn't want my dac chip to sound warm or any of that other stuff. I would only want it to be accurate.
     
  15. Black Elk

    Black Elk Music Lover

    Location:
    Bay Area, U.S.A.
    Sure, any designer of digital-to-analog converters (the complete item, not just the converter) using a DAC chip will have looked at the specs. and architecture of various chips, and will likely have built a test-bed so that they can evaluate the chips with their analog stage. However, as others have pointed out, it is not a simple case of swapping chips. Pin-layouts can be different, operating voltages can be different, operating frequencies can be different, there are different digital filters (on-board or external), etc. Some times it can be easier to just pick a chip with good linearity, low-noise, etc., and try to optimize its sound quality via appropriate digital filter and analog stage designs.

    There are many, many variables in D-to-A conversion (type, order, filters, noise-shaping, aliasing, ripple, linearity), so it should not be surprising that chips will sound different. You just have to accept that (for a given price) a designer has chosen the best in his/her opinion.

    As for the lampizator site, that came up in another discussion here some time ago, and I read some stuff there, and the guy does not know what he is talking about, especially with regard to oversampling.
     
  16. McGruder

    McGruder Eternal Musicphile

    Location:
    Maryland
    Well the type of DAC is obviously valid for telling part of the story, but as others have mentioned, there are many other aspects in the power supply design, shielding, caps and resistors used, clock, connectors, balanced vs. unbalanced etc that will contribute to the whole story or gestalt of the player or DAC.

    Different DAC designs can have sonic characteristics. For example, I find that components that use non-oversampled DACs tend to be more open sounding. On the other hand, they can also tend to have a little more edge or perhaps a clinical quality depending on the rest of the component design choices. This is not to say that all implementations that use NOS DACs will sound that way, but there does seem to be a correlation IME (and that of others). Oversampled DACs can sound fatter, or more full bodied, but maybe rolled off or warm, depending on the overall design. How I react to a particular design may be entirely different from you, so ultimately listening for yourself and forming your own opinion is going to be essential.
     
  17. riverrat

    riverrat Forum Resident

    Location:
    Oregon
    Dude, I was simply directing the OP to a site that contains an archive of a lot of discussion of the merits of different DACs and the chips they contain, with the proviso that it is very extensive and can be a time sink.

    I've learned a lot about DACs there (much more than on this site) but some of the discussions become absurdly arcane (to my way of thinking) and I think others might agree. But its no skin off my nose, if that's how people want to spend their time, that's their business. I was just commenting on that aspect of head.fi which I think is pretty obvious. In any case, there's no need to criticize me for mentioning it.

    Also, I hope you are smart enough to realize there's a lot of middle ground between having "no time", and having hours or days on end (and the level of interest) to spend on posting back and forth for page after page, or reading through every DAC thread there.
     
  18. McGruder

    McGruder Eternal Musicphile

    Location:
    Maryland
    I might have come off strong, but I like to advocate that people in this hobby take the time to learn about it. I didn't get that from your post, which it sounds like was a subtle editorial on diatribe on Head-Fi - so I apologize.

    I do encourage the OP to read and listen, since I think the facilities for measuring isolated DAC performance for comparison are not readily accessible. I think its worth the time to read, listen and learn - and its interesting. Audio Asylum or DIYAudio are better forums for discussion about DAC design than Head-Fi.
     
  19. riverrat

    riverrat Forum Resident

    Location:
    Oregon
    Thanks for these leads, will check them out.

    And apologies to the OP for going a bit off topic..
     
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