BNC vs RCA for Digital Audio

falconcry72
falconcry72 Posts: 3,580
edited August 2011 in 2 Channel Audio
Is there an inherent advantage to the BNC connector over RCA for digital audio?

My current USB to SPDIF converter (Musical Fideliy V-Link) only has Toslink optical and RCA coaxial digital outputs, but I might be getting a new one soon (Audio GD Digital Interface) which will have a BNC output in additon to the 2 afforementioned outputs. My DAC also has a BNC input.

Any input on these inputs is greatly appreciated! :smile:
2-Channel: PC > Schiit Eitr > Audio Research DAC-8 > Audio Research LS-26 > Pass Labs X-250.5 > Magnepan 3.7's

Living Room: PC > Marantz AV-7703 > Emotiva XPA-5 > Sonus Faber Liuto Towers, Sonus Faber Liuto Center, Sonus Faber Liuto Bookshelves > Dual SVS PC12-Pluses

Office: Phone/Tablet > AudioEngine B1 > McIntosh D100 > Bryston 4B-ST > Polk Audio LSiM-703's
Post edited by falconcry72 on
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  • FTGV
    FTGV Posts: 3,649
    edited August 2011
    The BNC will be a true 75ohm connector.Keeping all the connectors and cable at the SPDIF coaxial spec of 75 ohm's results in less reflections in the cable thus reduced jitter,in theory atleast.
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  • steveinaz
    steveinaz Posts: 19,538
    edited August 2011
    BNC is thought to be the best topology, but the important factor is how close the DAC and transports' 75ohm spec is held in their input/output circuits. All things considered, it's going to be extremely subtle.

    If I had the option, and both source and DAC had BNC connections---I'd use BNC. I'd get one of Blue Jeans Belden/BNC cables whipped up to custom length.
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
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  • falconcry72
    falconcry72 Posts: 3,580
    edited August 2011
    OK, so I'm thinking if I can go BNC I might as well.


    New Question:

    My PC is 25 ft from my 2 channel rig, and I use an external USB to SPDIF converter. Would it be better to:

    1) Use a short high quality USB cable, and then a long lower quality SPDIF cable.

    2) Use a long lower quality USB cable, and short high quality SPDIF cable.

    3) Find a wireless USB to USB device(does this even exist???), and go wireless to the converter and then a short high quality SPDIF cable.

    Thanks again,

    Ben
    2-Channel: PC > Schiit Eitr > Audio Research DAC-8 > Audio Research LS-26 > Pass Labs X-250.5 > Magnepan 3.7's

    Living Room: PC > Marantz AV-7703 > Emotiva XPA-5 > Sonus Faber Liuto Towers, Sonus Faber Liuto Center, Sonus Faber Liuto Bookshelves > Dual SVS PC12-Pluses

    Office: Phone/Tablet > AudioEngine B1 > McIntosh D100 > Bryston 4B-ST > Polk Audio LSiM-703's
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  • FTGV
    FTGV Posts: 3,649
    edited August 2011
    I would opt for a short USB then use somthing like Canare LS61 for the SPDIF.It's a reasonably priced excellent digital cable that can be custom ordered with Canares excellent BNC or 75 ohm RCA cons.25ft should not be an issue as the SPDIF maxium spec for coax is 30ft.
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  • BlueFox
    BlueFox Posts: 15,251
    edited August 2011
    Two follow-ups on this subject.

    What about digital XLR cables versus BNC/RCA?

    Currently, we can spend big bucks on RCA digital cables, and from my experience, I have gotten better results from the more expensive cable. However, for coax will the cable matter?
    Lumin X1 file player, Westminster Labs interconnect cable
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    Shunyata Triton v3/Typhon QR on source, Denali 2000 (2) on amps
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  • steveinaz
    steveinaz Posts: 19,538
    edited August 2011
    In my experience with my CEC and Benchmark (base model), XLR did give a slightly warmer/more analog presentation. Unfortunately the newer Benchmark/PRE dropped the XLR dig input. I used a 1mtr XLR (AES/EBU) cable from Signal cable.

    I never had a chance to do a true BNC-BNC connection, because only the BM had a BNC connection. I used a RCA-BNC connector; RCA from the CEC, BNC to the BM. I still found the XLR connection the most satisfying of any: BNC/Coax/Toslink.
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
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  • falconcry72
    falconcry72 Posts: 3,580
    edited August 2011
    BlueFox wrote: »
    Two follow-ups on this subject.

    What about digital XLR cables versus BNC/RCA?

    Currently, we can spend big bucks on RCA digital cables, and from my experience, I have gotten better results from the more expensive cable. However, for coax will the cable matter?

    My DAC's have digital XLR inputs, but none of my sources have the output. I have been wondering how they'd do.

    If a had a source with that output, I would definitely use it, especially since the rest of the system is balanced.
    2-Channel: PC > Schiit Eitr > Audio Research DAC-8 > Audio Research LS-26 > Pass Labs X-250.5 > Magnepan 3.7's

    Living Room: PC > Marantz AV-7703 > Emotiva XPA-5 > Sonus Faber Liuto Towers, Sonus Faber Liuto Center, Sonus Faber Liuto Bookshelves > Dual SVS PC12-Pluses

    Office: Phone/Tablet > AudioEngine B1 > McIntosh D100 > Bryston 4B-ST > Polk Audio LSiM-703's
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  • FTGV
    FTGV Posts: 3,649
    edited August 2011
    BlueFox wrote: »

    What about digital XLR cables versus BNC/RCA?
    The XLR(AES/EBU) is basically a balanced SPDIF signal mostly used in the pro ranks.
    However, for coax will the cable matter?
    As with regular IC's you will get various responses.:biggrin:
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