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  1. #1
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    Transporter playing 88 kHz files

    I have downloaded a Bill Evans Super HD album from Music Giants in .wma lossless format. Windows Media Player shows the file properties as 24/88 with a bit rate of 2.75 mbps for track 1.

    I was under the impression Transporter would not play 88.2 kHz files, however it plays fine, with Transporter showing a bitrate of 2760 kbps and a sample rate of 22.7 kHz.

    So...I'm a bit confused. Wass up?

    RG

  2. #2
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    Follow Up

    More confusion...

    Foobar and Winamp show file properties of these .wma files with the high bitrate but as 16/44.

    Strange...

    RG

  3. #3
    Senior Member adamslim's Avatar
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    It should play fine on the Transporter; if you want it on the SB3 then you should probably resample it down to 44.1, as the SB3 uses a rather simplistic system to play these (just skipping alternate samples, with no clever processing). There was also an old bug that made 24/88 FLAC files play at half speed, not sure if it applied to WMA.

    Many packages are surprisingly bad at providing true file information. SlimServer gets it wrong, so does Foobar and DBPowerAmp is not totally reliable, from memory, although is the best I used. Not sure if SS7 is any better, and never used WMP or Winamp.

    Adam
    SB3, Dac-in-the-Box, Sony VFET, Snell Type Cs
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  4. #4
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    Clarification

    Just to be clear, are you saying that Transporter now supports/plays 88.2 kHz files?

    I recall reading some older threads indicating Transporter would not play the 24/88 Linn files. I cannot recall if they were the wma or flac. Are you saying this is no longer an issue?

    The specs for Transporter only indicate Sample rates: 44.1kHz, 48kHz, 96kHz for digital outputs and inputs. Perhaps this is where my confusion is and in part contributed by John Atkinsons constant stating Transporter will not *handle* music files recorded at 88.2kHz, as recent as in the December issue of Stereophile in his 2007 Editor's choice column.

    Are you saying Transporter will play *handle* these files, just not through the digital ins or outs?

    RG
    Last edited by RGibran; 2007-11-17 at 21:11.

  5. #5
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    All is well

    Adamslim.

    My apologies if I sounded like I was grilling you. Actually you answered my question quite simply and apparently accurately.

    I downloaded the Linn 24/88 test file and also purchased a 24/88 song and both play without a hitch. Transporter shows the correct file properties as well.

    I guess I'm just going to have to ask John Atkinson what the heck he means when he continually states Transporter will not "handle" files recorded at 88.2 kHz.

    Thanks,

    RG

  6. #6
    Senior Member adamslim's Avatar
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    Quote Originally Posted by RGibran View Post
    Adamslim.

    My apologies if I sounded like I was grilling you. Actually you answered my question quite simply and apparently accurately.

    I downloaded the Linn 24/88 test file and also purchased a 24/88 song and both play without a hitch. Transporter shows the correct file properties as well.

    I guess I'm just going to have to ask John Atkinson what the heck he means when he continually states Transporter will not "handle" files recorded at 88.2 kHz.

    Thanks,

    RG
    No offence taken

    I think the key point is that mainstream hifi reviewers are going to get out of their depth with the 'new' technology. Out of the box his review Transporter may not have handled 24/88, but there is a highly transparent system of firmware updates and a good team making things better. It's a very different paradigm from mainstream hifi, which has often instant obsolescence (DAB vs DAB+ anyone?)
    SB3, Dac-in-the-Box, Sony VFET, Snell Type Cs
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  7. #7
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    Curious as to whether the highly transparent system of firmware updates and a good team making things better had gone the mile, I converted a 24/88 .wma which does play in Transporter although the sample rate is reported at 22.7 kHz, to 24/88 .wav using the free Microsoft wmal2pcm converter.

    Foobar, Winamp and WMP all play the file and show file properties as 24/88

    Transporter will not play this file, producing loud hiss with a very faint background of some music, too faint to be discernable.

    So I still find all this quite odd.

    At present it seems Transporter will play:

    24/88 wma at a slimserver reported high bit rate BUT diminished sample rate of 22.7 kHz.

    24/88 flac at a slimserver reported high bit rate and 88.2 kHz sample rate.

    Transporter will NOT play 24/88 .wav files!

    So I still question if Transporter is properly playing these 88.2 kHz file formats. Is it hit and miss? Are these inconsistencies bugs? Is it being worked on? Was Transporter never intended nor will it ever support 88.2 kHz?

    I’m a bit surprised the powers to be won’t step up to the plate and give us the true skinny.

    Also a bit surprised this thread has attracted only one responder. Perhaps no one cares about Hi-Res through the Transporter?

    Perhaps John Atkinson is correct when he states Transporter will not “handle” 24/88 Hi-Res files. It’s certainly not handling them consistently in my experience.

  8. #8
    Junior Member struts's Avatar
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    Quote Originally Posted by RGibran View Post
    Windows Media Player shows the file properties as 24/88 with a bit rate of 2.75 mbps for track 1.

    I was under the impression Transporter would not play 88.2 kHz files, however it plays fine, with Transporter showing a bitrate of 2760 kbps and a sample rate of 22.7 kHz.
    A two-channel bit rate of 2760 kbps implies a sample rate of 57.5 kS/s with 24-bit words. If the codec is compressed and the bit rate refers to the compressed stream (as I believe is the case with Windows Media Player) rather than the raw PCM then the implied sample rate is higher. WMA lossless achieves on average just under 50% compression so this would imply an original sample rate in the region of 100 KS/s, which is about right. However, the same bit rate and a sample rate of 22.7 kS/s would imply a word length of over 60 bits so simple division would suggest that at least one of these parameters is being wrongly reported.
    Last edited by struts; 2007-11-19 at 16:17.

  9. #9
    Founder, Slim Devices seanadams's Avatar
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    Transporter does not properly support 88.2. Currently if you are hearing it play 88.2, it is because it is being decimated in software.

    The crystals were chosen to do 44.1, 96, and fractions thereof. Why not put a crystal fast enough for 88.2 in there? Because when you are trying to minimize jitter, EMI, noise etc, you use the slowest possible clock rates, the least possible amount of clock dividing, etc.

    Since demand for 88.2 has now materialized, I will investigate if there is a way to make it do it. It may be possible to do with the existing crystals - certainly the rest of the system (eg the CPU) can handle it since we're doing 96KHz.

  10. #10
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    Quote Originally Posted by struts View Post
    A two-channel bit rate of 2760 kbps implies a sample rate of 57.5 kS/s with 24-bit words. If the codec is compressed and the bit rate refers to the compressed stream (as I believe is the case with Windows Media Player) rather than the raw PCM then the implied sample rate is higher. WMA lossless achieves on average just under 50% compression so this would imply an original sample rate in the region of 100 KS/s, which is about right. However, the same bit rate and a sample rate of 22.7 kS/s would imply a word length of over 60 bits so simple division would suggest that at least one of these parameters is being wrongly reported.

    Gee Struts,

    It’s obvious I’m having trouble putting two and two together and now you want me to divide something?

    Hey, great to see you over here. I hope you didn’t just drop in on my account but I greatly appreciate your input, as always.

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