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  1. #1
    Join Date
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    Default ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    I have been exploring the realm of the "low cost DAC". This is the second DAC that I am reporting on.

    Now here we have a real contender - the "Little Bear Decoder v1.08". This is a 48kHz/96kHz spdif input DAC using a DIR9001 spdif receiver IC and the CS4398 D-to-A chip. The output is run through a 5532 op amp to provide low pass filtering and to buffer the output. The quality of the board seems to be high and good quality parts are used in critical areas.

    I performed some measurements on this DAC using an M-Audio ProFire610, ARTA/STEPS and REW. For these measurements, the signal path begins in software, goes to the 610 spdif output port, into the DAC, and then back into an analog input port of the 610. Software can then evaluate the analog input (for distortion, frequency response, etc.). This signal path also permits me to do A/B testing (after level matching) of the 610's internal DAC and the external DAC using the 610's routing software.

    I have attached the measurements I obtained. At both 48kHz and 96kHz the distortion levels are low and more or less input-level independent. I also took a spectrum of the DAC output for a 1kHz test tone, showing distortion products and the noise floor, both of which are very low. Keep in mind that the distortion spec for the analog input of the M-Audio Profile 610 that I am using to measure this DAC is 0.002% distortion (at 1kHz -1dBFS) and -108dB S/N ratio (A-weighted). Essentially the "Little Bear" DAC is approaching the measurement threshold of my equipment.

    This is an exceptional product, especially given that I purchased it for $40 including shipping to the USA. Power is supplied via a single 12-0-12 VAC input, and a transformer is included by the seller (115VAC or 230VAC primaries are available). Once you connect the transformer the unit is ready to run.

    If you are looking for an SPDIF input (only) DAC then this is really one that performs far above its price level.

    Ebay link:
    HiFi Digital to Analog Coaxial Decoder DIR9001 CS4398 96kHz 24bit DAC Converter | eBay (or search under "Decoder DIR9001 CS4398")
    Aliexpress link:
    Little Bear DAC on Aliexpress.com



    Click image for larger version. 

Name:	Little Bear DAC v1.08 distortion at 0dB 48kHz SR.png 
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Name:	Little Bear DAC v1.08 distortion at -20dB 48kHz SR.png 
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    .
    Charlie's Audio Pages: http://audio.claub.net

  2. #2
    Join Date
    Jul 2006
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    Davis, CA
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    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Frequency response plots and spectrum are shown below.

    Click image for larger version. 

Name:	Little Bear DAC v1.08 frequency response 48kHz SR.png 
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    Charlie's Audio Pages: http://audio.claub.net

  3. #3
    Join Date
    Jun 2008
    Location
    Arizona
    Posts
    1,305

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Great deal at that price. Thanks for letting us know!

  4. #4
    Join Date
    Jul 2011
    Location
    SoCal
    Posts
    1,362

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Nice. Wish it had USB input so I could use it from a computer. I see the seller has a USB to coax converter but that no longer makes it so affordable.
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  5. #5
    Join Date
    Sep 2005
    Location
    Irvine, CA
    Posts
    1,634

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Good to see ya kicking around, Charlie...

    Second one, did I miss something? Wondering if you've considered the "Objective DAC", by that NWavguy... Or some of the cheaper ESS DAC's out there... A set of affordable DACs with the digital only miniDSP processor, would make a nice package...

  6. #6
    Join Date
    Dec 2011
    Location
    Bellevue, WA
    Posts
    195

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Nice find, I wonder if they'll make a balanced version.

  7. #7
    Join Date
    Dec 2011
    Location
    Deer Park
    Posts
    890

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    I might grab one and run it through an audio precision to compare our results.

  8. #8

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    The harmonic distortion profile is buried. Nice.

  9. #9
    Join Date
    Sep 2005
    Location
    Placentia, CA
    Posts
    1,755

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    A diamond in the rough. Thanks Charlie for showing that good stuff doesn't have to cost an arm and a leg.

  10. #10
    Join Date
    Sep 2010
    Location
    Baltimore
    Posts
    4,120

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    The eBay seller added your post from DiyAudio to their listing.
    रेतुर्न तो थे स्रोत

    return to the source



  11. #11
    Join Date
    Jul 2006
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    Davis, CA
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    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Quote Originally Posted by greywarden View Post
    The eBay seller added your post from DiyAudio to their listing.
    Ah, that's no problem. I told him that I wrote about it. I think it is a really great deal, provided you only need coax spdif input (which I do). I told him that there would probably be others who would want to buy one so he has made some more available.

    The ironic thing is that you have to be a member and logged in at DIYaudio to see the images.
    Charlie's Audio Pages: http://audio.claub.net

  12. #12
    Join Date
    Sep 2010
    Location
    Baltimore
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    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    At $35-40 it they would be a good combo to use with the MiniDSP digital 2x8 box, as it's nearly impossible to find affordable amplifiers with digital inputs and high quality DACs on-board.
    रेतुर्न तो थे स्रोत

    return to the source



  13. #13
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    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Quote Originally Posted by greywarden View Post
    At $35-40 it they would be a good combo to use with the MiniDSP digital 2x8 box, as it's nearly impossible to find affordable amplifiers with digital inputs and high quality DACs on-board.
    I think you mean this (the nanoDIGI):
    http://www.minidsp.com/products/mini...nanodigi-2x8-k
    Charlie's Audio Pages: http://audio.claub.net

  14. #14
    Join Date
    Sep 2010
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    Baltimore
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    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Quote Originally Posted by charlielaub View Post
    I think you mean this (the nanoDIGI):
    http://www.minidsp.com/products/mini...nanodigi-2x8-k
    Yeah that one.
    रेतुर्न तो थे स्रोत

    return to the source



  15. #15
    Join Date
    Dec 2005
    Location
    coastal AL
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    642

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Thanks for the tip! I have about 10 different DACs on my "watch list" on eBay. Just haven't been able to pick one and pull the trigger yet. This is a helpful vote of confidence.
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  16. #16
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    Jul 2006
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    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Quote Originally Posted by scottq View Post
    Thanks for the tip! I have about 10 different DACs on my "watch list" on eBay. Just haven't been able to pick one and pull the trigger yet. This is a helpful vote of confidence.
    Apart from having pretty good performance and sound quality, it's super easy to use because the "power supply" (the transformer) is included! Just connect the wires, plug in the transformer, and start listening. Some of the DAC kits on Ebay need multiple AC or DC inputs, and you have to add the power supply cost on top of the board cost.

    The only shortcoming, if you can call it that, is that the maximum sample rate for the "Little Bear DAC" is 96kHz so if you want to use a higher rate you are out of luck. Personally I can't tell any difference (audible) once you get above 48kHz, making ultra-high sample rates a non-starter for me.
    Charlie's Audio Pages: http://audio.claub.net

  17. #17
    Join Date
    Dec 2012
    Location
    Vancouver, WA
    Posts
    109

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Newb question. Does an optical to spdif converter really work or is not even worth it? Trying to find something to go with apple tv or apple airport express.

  18. #18
    Join Date
    Jul 2006
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    Davis, CA
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    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Quote Originally Posted by fwiler View Post
    Newb question. Does an optical to spdif converter really work or is not even worth it? Trying to find something to go with apple tv or apple airport express.
    Do they work - yes, definitely. At these sample rates I think that even an inexpensive one (as long as it is powered) will work properly. Both electrical and optical spdif signals are the same.
    Charlie's Audio Pages: http://audio.claub.net

  19. #19

    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Did the $40 DAC get compared to the Benchmark at InDIYana?

  20. #20
    Join Date
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    Default Re: ALERT: good spdif input 24/96 DAC for only $40 (with measurements)

    Quote Originally Posted by jinjuku View Post
    Did the $40 DAC get compared to the Benchmark at InDIYana?
    Nope.
    Wolf
    "Wolf, you shall now be known as "King of the Zip ties." -Pete00t
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