Home of the Squeezebox™ & Transporter® network music players.
Results 1 to 8 of 8
  1. #1
    Junior Member
    Join Date
    Jul 2005
    Location
    The Netherlands
    Posts
    14

    Stretching the Touch

    Hi all,

    I have been enjoying my Touch (with EDO) for a very long time and plan to continue to do so!

    Now recently my USB DAC received a hardware upgrade and supports plenty of additional hires formats (up to 32bit/384kHz and up to DSD256).
    I downloaded some test-files from MSB and managed played them all back with my old Lenovo X220 laptop under Ubuntu 19.10 using ALSA.

    I know the Touch doesn't support 32bit, but my hopes were for 24bit/352kHz or even 24bit/384kHz, especially since I read some sporadic reports on the Touch supporting higher than 192kHz bitrates (without any further information). I think >192kHz is even listed in the file of compatible DACs.

    Does anyone know what the limiting factor(s) on the Touch would be to support these higher bitrates? Such hires content hardly exists, so it is still perfectly fine as it is for now. But I would like to know more why it might be possible/impossible to extend the range of supported hires encodings.

    Any information related to this would be highly appreciated.

    Kind regards,
    Jan

  2. #2
    Senior Member Julf's Avatar
    Join Date
    Dec 2010
    Posts
    2,509
    Quote Originally Posted by jma2 View Post
    Does anyone know what the limiting factor(s) on the Touch would be to support these higher bitrates? Such hires content hardly exists, so it is still perfectly fine as it is for now. But I would like to know more why it might be possible/impossible to extend the range of supported hires encodings.
    As you say, such "hires" content hardly exists. I haven't seen a commercial DAC that has an effective number of bits [ENOB] of more than 22 bits. All a higher sample rate gives you is ability to reproduce ultrasonic frequencies - only useful if you are a dog or bat. I guess this discussion really belongs in the "audiophile" section...
    "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

  3. #3
    Junior Member
    Join Date
    Jul 2005
    Location
    The Netherlands
    Posts
    14
    Dear Julf,

    It seems I didn't properly present my question. In a way my question has nothing to do with "audiophile" or with entertaining dogs and bats

    I use my Touch (with EDO) as a kind of "gateway" between my LMS server and my USB DAC and am wondering where are the limitations that prevent for example unmangled 24bit/352kHz transfer by my "gateway" (are they linux kernel limitations or processing power limitations, USB interface limitations, a combination of those or something else?).

    The whole "audiophile" angle, and whether it makes sense or not to have such hires or not, I leave that to everybody to decide for themselves. The fact is that at least the test files are there (see the link in my first post) to play with which is what I did.

    Kind regards,
    Jan

  4. #4
    Senior Member
    Join Date
    Dec 2011
    Posts
    118
    The Touch is very much the weak point in your scenario and is quite an old (relatively speaking) design.

    This was designed for 24 bit / 96k - this has been "tweeked" to allow 192K playback but this is probably the highest rate that could be achieved.

    Also the usb was originally for input only (memory stick / hdd) and this was also tweeked to allow connection to an external usb dac. As the touch (with edo) reports to lms that the maximum playback rate is 192k you can't get more than that from the usb.

    Best bet may be to set something up with a pi

  5. #5
    Junior Member
    Join Date
    Jul 2005
    Location
    The Netherlands
    Posts
    14
    Thank you steve-g! Highly appreciated!

    I may indeed go to the piCore player on a Raspberry-pi with a touch screen as an alternative to the Touch.

    Still somewhere deep down I feel that, although the Touch is old (end of 2009 if I am correct), there might be some potential in it. I do not have the in-depth knowledge on the SW and HW aspects, so it is difficult to substantiate this feeling and what I write below is pure speculation from my part and might be totally wrong:

    The USB interface would be USB2.0 I assume and even though initially designed as an input, Triode (big respect!) managed via EDO to let it operate as an output. That for sure must eat away some processing power.
    On the other hand no real music-decoding has to take place in EDO->USB mode, so some processing power might be saved (unless audio decoding happens in some side-DSP).
    At that time (EDO announced in 2012) 192kHz bitrate was already outrageous, so it already felt like wooow. You seem to suggest that the Touch (with EDO) reports itself to the LMS with a max playback rate of 192kHz. What if it did announce itself with for example a maximum playback rate of 384kHz?
    There may also be buffering issues at higher bitrates which might be bound to memory capacity limitations.
    I haven't seen Triode around here for a long time (I wasn't active here for a long time myself), so it might be difficult to get to the real bottom of this, but it would for sure be interesting to here more about it.

    I know, Raspberry Pi's are plenty powerful, so why bother?! Well maybe because I still like my Touch too much

  6. #6
    Senior Member Julf's Avatar
    Join Date
    Dec 2010
    Posts
    2,509
    Quote Originally Posted by jma2 View Post
    At that time (EDO announced in 2012) 192kHz bitrate was already outrageous
    It still is...
    "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

  7. #7
    Senior Member Apesbrain's Avatar
    Join Date
    Jun 2005
    Location
    East Coast, USA
    Posts
    1,383
    FYI, pretty sure the Touch with appropriate plugins supports DSD64. Your DAC needs to understand DoP (DSD over PCM).

  8. #8
    Junior Member
    Join Date
    Jul 2005
    Location
    The Netherlands
    Posts
    14
    Quote Originally Posted by Apesbrain View Post
    FYI, pretty sure the Touch with appropriate plugins supports DSD64. Your DAC needs to understand DoP (DSD over PCM).
    I have that one working indeed since quite some time.

Posting Permissions

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