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CD Players, Digital Music & Servers Aurender, dCs, Esoteric, Lumin. |
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Music Server Set-up Considerations
A member in another forum posted a comment about digital-based "streaming" systems. The initial, comment, "quoted" below, was around using an Ethernet switch to send digital music files from an "upstream" music server computer downstream to a network bridge, streamer, DAC, or streamer/DAC set-up in the main audio rack, and some of points were accurate, but additionally, some were not. Thought the gang might find his comments and some additional info I posted in response to his original post to be useful with respect to setting up a networked music server-type digital audio system. Cheers, gents.
Quote:
1) The "signal" from a digitally-encoded music file is not a series of 0's and 1's. The only thing that is "digital" is the encoding of the music file, itself. The "signal" sent from the music server to the Ethernet switch and then downstream to a network bridge, streamer and/or DAC, etc. is an analog square wave voltage, typically with 0V representing a "0" in the digital "file" and +2V representing a "1". And, with respect to "jitter" there are different types of jitter. The one you've referred to above is likely "deterministic" jitter but there is also random jitter, and importantly for reproduction of digitally-encoded music, threshold jitter. Threshold jitter is important because it results in timing errors, which our brains are exquisitely sensitive to when listening to digitally-encoded music. We can hear timing errors in the picosecond time-domain, which is why our digital music devices require femtoclocks. The impact of some of these noise factors looks like this: This drawing shows the impact of jitter on the "timing" of the music signal. Another key noise factor that is audible is phase noise, which looks like this, and can result timing errors, which as mentioned above, we are very, very sensitive to when linsteing to music. Moreover, all metal-conductor (copper, silver, etc) based digital cables, including Ethernet and USB, are susceptible in carrying these noise factors, and well as low-and high-source impedance leakage current. In particular, the high-source impedance leakage current is problematical because it results in the threshold jitter referenced above. You can read about the influence of high-source impedance leakage and threshold jitter in a white paper by EtherREGEN designer and professional Ethernet engineer, John Swenson, here: https://shorturl.at/l0146 A very effective way to mitigate the impact of leakage current and threshold jitter is to send the file data via LC/LC optical fiber from the music server, Ethernet switch, etc. to the downstream (in the audio rack, that is) network bridge, streamer, and/or streamer/DAC. The advantage of optical fiber, is because the data is encoded as light signals, by definition, it can't carry low-and high-source impedance leakage current (though it can still have phase noise from any crap, upstream clocks in generic digital devices e.g. routers, switches, generic FMCs, etc.) In addition the various types of jitter and phase noise, digital cables, including Ethernet, USB, S/PDIF, etc also carry common-mode noise, so you have to manage that as well. Reference for impact of Common-mode Noise for audio applications: https://community.element14.com/lear...o-applications So, once the music file data is sent from the "upstream" music server computer, e.g. via optical fiber, downstream to the network bridge or stream in or near the main audio rack, you want to mitigate common-mode noise using the appropriately-designed Ethernet and USB cables. This should help to clarify some key points. Cheers.
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Lumin P1 streamer/DAC/preamp, Constellation Inspiration integrated TT: Michell Gyro SE MkII, SME V, Koetsu Urushi Vermilion, EAR324. Harbeth 30.2s, REL R-305, Shunyata Alpha V2 ICs, Alpha V2 SPs, Sigma XC, Sigma NRv2, Omega QR-s & Alpha NRv2 PCs, segmented Altaira SG stack w/ Alpha & Omega CGCs, Everest 8000 PD. Remote Server Room: Uptone EtherREGEN, AfterDark Master Clock & LPS, Alita, Battle Angel, (Akasa NUC Roon Core), iFi DC Purifiers (for SMPS used for Alita & router), Shunyata Gemini combo power distributor & Altaira-type CG GP-NR hub, Venom & Alpha CGCs, Shunyata NRv14 power cords for digital components. Last edited by Puma Cat; 02-11-2024 at 03:15 PM. |
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