Home of the Squeezebox™ & Transporter® network music players.
Results 1 to 10 of 10
  1. #1
    Senior Member
    Join Date
    Mar 2016
    Posts
    120

    a/synchronous DACS... APPS

    hi all..

    A guys selling a SBT and says hes been using a Audiolab MDAC and using a external 3rd party app via SBT . He seems the think the MDAC is asynchronous DAC. Correct me if Iam wrong here, but iam sure it is not, only maybe the Input Connection itself.
    To qualify as an asynchronous DAC, every input of the DAC (not just the USB) would be asynchronous – where the designer would throw away the source clock and rely only on the DAC’S internal clock. There are scarce few of these around..and expensive.

    I recently bought the new Rega DAC and that claims a asynchronous Input. (I never tried it with the App-But doubt that would of made a difference at 192K )

    It makes perfect sense now when I tried the Rega DAC with my CD player, Why it Sounded better(a better source output than the SBT)

    or like one guy commented" the DACS not making your CD Better, The CD Player making the DAC sound better"!

  2. #2
    Senior Member
    Join Date
    Apr 2013
    Location
    UK
    Posts
    902
    DACs often reclock, but they have to "tune" their internal clock source to take account any small variation between it and the incoming data rate. Unfortunately the act of using a clock that can be tuned tends to reduce its jitter performance somewhat so the ideal is asynchronous USB, whereby the DAC requests data from the player on its own timing rather than the player sending data on its own timing.

    I have a DAC that can do either and is capable of reclocking, but using its internal clock only results in pops and clicks as the data stream goes out of sync (buffer empty, or buffer full), so in reality it's not usable this way. I leave it synced to input data stream from the SBT and it works fine..
    --
    Hardware: 3x Touch, 1x Radio, 2x Receivers, 1 HP Microserver NAS with Debian+LMS 7.9.0
    Music: ~1300 CDs, as 450 GB of 16/44k FLACs. No less than 3x 24/44k albums..

  3. #3
    Senior Member Julf's Avatar
    Join Date
    Dec 2010
    Posts
    2,396
    I think there is confusion between "asynchronous DAC" and "DAC with asynchronous USB input" here.

    Yes, a DAC can run in a completely independent clock domain (from a clock completely isolated from the input), and this is fairly common these days. The problem is of course getting ahead or behind the output data stream. Asynchronous USB allows the DAC to regulate the flow of data from the source, but with other types of input this is not an option, so the standard solution is either to derive the DAC clock from the input data clock using a phase locked loop (that smooths out any jitter), or an asynchronous sample rate converter.
    "To try to judge the real from the false will always be hard. In this fast-growing art of 'high fidelity' the quackery will bear a solid gilt edge that will fool many people" - Paul W Klipsch, 1953

  4. #4
    Senior Member
    Join Date
    Apr 2013
    Location
    UK
    Posts
    902
    Yeah the name "asynchronous" seems to usually refer to DACs that support the USB2 asynchronous audio driver, not the other type that just uses an independent clock, despite it being arguable that both are a type of asynchronous..
    --
    Hardware: 3x Touch, 1x Radio, 2x Receivers, 1 HP Microserver NAS with Debian+LMS 7.9.0
    Music: ~1300 CDs, as 450 GB of 16/44k FLACs. No less than 3x 24/44k albums..

  5. #5
    Senior Member
    Join Date
    Mar 2016
    Posts
    120
    Thanks for that Info. When I used my Rega DAC, (NOW SOLD) I Only used analogue Inputs/outputs, not the Asynchronous USB, Iam just wondering if that may of altered the sound somewhat with the 3RD PARTY APP download..? or would it just been a case of the DAC requesting the Info when it wanted...

  6. #6
    Senior Member
    Join Date
    Apr 2013
    Location
    UK
    Posts
    902
    Basically unless it's connected via USB2, the DAC is slaved to the SBT, using EDO or otherwise.
    --
    Hardware: 3x Touch, 1x Radio, 2x Receivers, 1 HP Microserver NAS with Debian+LMS 7.9.0
    Music: ~1300 CDs, as 450 GB of 16/44k FLACs. No less than 3x 24/44k albums..

  7. #7
    Quote Originally Posted by daleyb View Post
    Thanks for that Info. When I used my Rega DAC, (NOW SOLD) I Only used analogue Inputs/outputs, not the Asynchronous USB, Iam just wondering if that may of altered the sound somewhat with the 3RD PARTY APP download..? or would it just been a case of the DAC requesting the Info when it wanted...
    what do you mean, you only used an "analogue input" ? you obviously need to be sending a digital signal to the DAC in order to be using it as a DAC. If you havent been using the EDO plugin in order to get a USB digital output from the touch -then the only other way you could get a digital signal to the DAC would be via optical/toslink or coaxial.

    many users do agree that using the EDO app to get a USB output from the touch, at up to 24/192, is indeed the best way to go (obviously it depends if you have files at that resolution). however, it also depends on how good the DAC is. If you didnt hear any difference at 24/96 then it would appear that the rega DAC isnt any better, on whatever your system reveals anyway (and it does obviously depend on what amp and speakers you have) than the built in dac of the touch -which isnt that surprising since the built in dac is pretty good.
    Last edited by tusken; 2017-01-10 at 09:37.

  8. #8
    Senior Member
    Join Date
    Apr 2013
    Location
    UK
    Posts
    902
    I am assuming the phrase "analogue input" refers to the coaxial digital link myself.
    --
    Hardware: 3x Touch, 1x Radio, 2x Receivers, 1 HP Microserver NAS with Debian+LMS 7.9.0
    Music: ~1300 CDs, as 450 GB of 16/44k FLACs. No less than 3x 24/44k albums..

  9. #9
    Senior Member
    Join Date
    Mar 2016
    Posts
    120
    Correct , I meant coaxial digital link.

    Just out of interest then, How would you connect a USB FROM SBT TO DAC as Asynchronous .Which Output on the SBT would you use..?....... I always thought the USB ON the SBT was INPUT ONLY.

    ps. I have NO 24/192 FILES anyway, only CD RIPPS (at present)
    Last edited by daleyb; 2017-01-11 at 07:02.

  10. #10
    Senior Member Mnyb's Avatar
    Join Date
    Feb 2006
    Location
    Västerås Sweden
    Posts
    16,044
    Quote Originally Posted by daleyb View Post
    Correct , I meant coaxial digital link.

    Just out of interest then, How would you connect a USB FROM SBT TO DAC as Asynchronous .Which Output on the SBT would you use..?....... I always thought the USB ON the SBT was INPUT ONLY.

    ps. I have NO 24/192 FILES anyway, only CD RIPPS (at present)
    The EDO app for Touch supports async usb 2.0 and sample rates 24/192 , but disables the analog out .
    --------------------------------------------------------------------
    Main hifi: Touch + CIA PS +MeridianG68J MeridianHD621 MeridianG98DH 2 x MeridianDSP5200 MeridianDSP5200HC 2 xMeridianDSP3100 +Rel Stadium 3 sub.
    Bedroom/Office: Boom
    Kitchen: Touch + powered Fostex PM0.4
    Misc use: Radio (with battery)
    iPad1 with iPengHD & SqueezePad
    (spares Touch, SB3, reciever ,controller )
    server HP proliant micro server N36L with ClearOS Linux

    http://people.xiph.org/~xiphmont/demo/neil-young.html

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •