SPDIF slave or selectable sample rates (48/44.1)

    Somebody (preferably from Kemper) please confirm whether this is fixed with the latest Beta. Im running the latest Beta - and I no longer have to source SPDIF clock on my audio interface.


    I would like to know why this works now - when it didnt before.


    Thanks a ton!

    Any update on the beta slaving to another SPDIF rate? From my short period of fooling with the Kemper, being able to change the SPDIF rate would clean up reamping significantly.

    [quote='kneelie',index.php?page=Thread&postID=82671#post82671]I would love 192k/24bit, 176.4k/24bit, or 96k/24bit. out, but what is the internal sample rate because a raw output of that would be best to limit the number of needless conversions.


    found this:
    9. Can you talk about what’s under the hood (processors, speeds, sampling rate, A/D conversion etc)?


    The main DSP is a Freescale DSP (formerly Motorola) running at an equivalent of 400 MHz speed. The code consists of tens of thousands of lines of pure assembler code. The global sampling rate is 44.1 kHz, while the internal sampling rate is partially much higher. The algorithm for the tube simulation runs on more than 700 kHz sampling rate (!).


    source: http://www.guitar-muse.com/kemper-profiling-amp-2949-2949


    Looking at the Freescale site, something like the Freescale Symphony series DSP56720 looks about right: dedicated audio DSP, dual core 2x200 Mhz = 400 Mhz equivalent, supports SDRAM, SRAM, DRAM, EPROM, Flash, SPDIF built in, 10 yr longevity program.
    I can imagine that you want to keep the signal chain at 1 samplerate, so in first instance that would also be what goes to SPDIF.
    On the other hand, the 56720 has a Asynchronous Sample Rate Converter (ASRC) that possibly may be used to convert 44.1 to 48 kHz at the backend for SPDIF.
    According to Freescale:
    The ASRC is hard-coded and implemented as a co-processor, requiring minimal CPU or DSP controller intervention.
    - allows multiple audio data rates in a system
    - 10 channels
    - supports input and output sample rates from 32 kHz to 192 kHz
    - supports three asynchronous output clock domains simultaneously
    So my 2 cents: if this is the DSP then hardware supporting sample rate conversions appears to be available

    got finally used to reamp in 44.1 but still no slave mode, it is a shame !!!!! every gear since SPDIF exist has that feature...... :cursing:

    Sorry to bump this old thread, but I'm now tracking guitar for a session that was originally tracked at 48 kHz. The fixed 44.1 sample rate on the SPDIF means I'm stuck using analog ins and outs on the Kemper for this project. Not a huge problem, really, but definitely far from ideal.


    If SPDIF slave and/or user-selectable sample rate is a possibility in a future release, I'd love to have it!

    Quote from nightlight

    Not happening, guys. Mr CK explained that having a converter capable of switching sample rates would have made the Kemper more expensive than it already is. Just use analog, or like I do, stick to 44.1 khz. Hardly the issue it's blown up to be, the analog outs work just fine.

    Well, like I said, it's not a make-or-break feature, but it does mean the SPDIF is essentially useless for most of what I do. Reamping entirely in the digital realm would have been excellent.


    Thanks for the info.

    Quote

    Not happening, guys. Mr CK explained that having a converter capable of switching sample rates would have made the Kemper more expensive than it already is. Just use analog, or like I do, stick to 44.1 khz. Hardly the issue it's blown up to be, the analog outs work just fine.


    Did CK mention if slave was coming instead of the KPA having to be the master all the time



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