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TOPIC: How was the SHD jitter improvement made?

How was the SHD jitter improvement made? 3 weeks 6 days ago #54703

  • asx77
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Hi guys,
In their original review of the SHD (www.audiosciencereview.com/forum/index.p...p-and-streamer.4286/), Audio Science Review complained about jitter: "....this graph which indicates a ton if interference from rest of the unit (DSP?) causing the myriad of noise and jitter spikes."

But it seems minidsp reacted, made changes and in an updated review (www.audiosciencereview.com/forum/index.p...-dac-streamer.18681/) those problems have been addressed. "We see faint signs of the original problem but they are now very nicely attenuated and at -130 dB and lower, not remotely an audible concern."

Does anyone know how and when the SHD design was changed to address this? Was it done through firmware or a hardware change?

Thanks
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How was the SHD jitter improvement made? 3 weeks 6 days ago #54706

  • entripy
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Possibly as simple as tweaking a few pcb track routes. Its likley the schematic hasn't changed to improve jitter. When you are working on such high quality systems the last bit of performance is often found by just juggling what you've got and seeing what works. This is where it tends more towards art rather than science.
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How was the SHD jitter improvement made? 3 weeks 6 days ago #54707

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Ok, so definitely hardware change then.
Any idea when minidsp made the change and/or from what serial number it applies? I guess really that's a question for support.
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How was the SHD jitter improvement made? 3 weeks 6 days ago #54708

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I think it was early this year when the updates reached users, no idea of serial numbers but I believe one of the USB connectors changed colour. It is highly unlikely but not totally impossible that this colour change improved jitter :)
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How was the SHD jitter improvement made? 3 weeks 6 days ago #54710

  • notman
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To be clear, the “updated” ASR measurements were taken from a machine with the “old” Neo2 hardware. The “new” hardware that started shipping in January hasn’t been measured, but miniDSP says the switch of the Pi board makes no performance difference.

It’s my understanding is the jitter optimization happened quite soon after the original ASR measurements. Not sure when exactly but if your machine is, say, a 2019 or later it’s probably representative of the updated measurements. Not that anyone including Amir thinks the original SHD had audible problems!
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How was the SHD jitter improvement made? 3 weeks 6 days ago #54721

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Hi @notman. My SHD was bought April 2020 so representative of the second ASR measurements then. Your last post is very insightful. Thanks
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How was the SHD jitter improvement made? 3 weeks 4 days ago #54763

  • maxxx_hifi
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Hi @asx77,,

where do you read the production date on the SHD?
I've bought a second hand unit and I wonder if it is a first or a second generation...

Thanks in advance for your help
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How was the SHD jitter improvement made? 3 weeks 4 days ago #54764

  • asx77
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Mine is 2nd hand too. I only know the original owner purchased it direct from minidsp in April 2020
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