Best practice XLR to RCA or straight RCA to RCA / XLR to XLR cables?

Discussion in 'ZIDOO X20 PRO' started by Nice Monkey, Jul 14, 2018.

  1. Nice Monkey

    Nice Monkey Well-Known Member Beta test group

    The Pro has XLR connectors with aclaimed quality components for the electronics. XLR was designed to minimize the pick up of noise with long (5m+) to very long cables (50m+) in mind (Headsets and Theater/Stage deployments)

    As hardly any XLR inputs are found on even quality home Amplifiers the question pops up either to use XLR to Analog cables or native quality RCA cables. My research learns the following using XLR and XLR to RCA cables:
    - Using a soldered passive XLR to RCA cable the XLR advantages are totally lost. Use such a cable only if there is no other way to inter-connect both for cables up-to 2m in length. Output RMS peak is typically 4V for XLR instead of 2V for RCA but XLR on the Zidoo audio panel has been verified by Zidoo labs to peak RMS output 2.26V. To avoid (heavy) distortion one can reduce the peak output level using the corresponding setting in setup.
    - Doing XLR to RCA the right way above 2 m can be done but involves transformers and/or other active components at the RCA end. For a short cable of 1 to 2 meters this is not practical and with doubtful signal improvements over a direct wired cable.
    - Even XLR to XLR may not be better than RCA to RCA depending on how XLR actually is build inside the receiving and transmitting ends and the length of the cable. An XLR setup should use 2 amplifiers for left and right each and the ground of XLR may not be connected to the ground of the amplifier. Some designs use a single differential amplifier which is connected to ground. Only in the case of correct designs at both ends then XLR is clearly superior for the long haul. If correct at one end only then the result may vary. It is recommended by experts to try both variants when available in general.

    Question to Zidoo: How is XLR technically designed? Has it floating ground on the XLR ground pins as it should have? Not that it is that important as I see including XLR as a showoff for home deployments. It is also a nice way to show the difference between the back of X20 and X20 Pro.

    My conclusion: For connecting X20 Pro use quality direct wired XLR-to-RCA cables up-to 2m.
    General best practice will be using RCA to RCA when available with a quality cable and forget about XLR if your amplifier/TV only has RCA inputs (my estimate 99.9x% of all cases).
    Last edited: Feb 28, 2019
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  2. Nice Monkey

    Nice Monkey Well-Known Member Beta test group

    Strange that there is no reaction at all?

    To add maybe the X20 Pro finds it way to (semi-)professional performers and DJ's; there the XLR output will be 100% in place. Also the fact that the setup allows to invert phase of the XLR output can be very handy then. I see the box very usefull for those deployments during stage setup/pauses etc.
    Last edited: Jul 17, 2018
  3. myzidoo

    myzidoo Member Beta test group

    don't want to turn the thread in an esoteric audiophile thingy....xlr shall be cleaner by the dedicated ground isolation wire. Now depending on your system some pretend you might hear (that's where the woodoo starts) a difference between xlr wiring and rca but frankly I was never able to tell in blind tests.
    Audiophile gear most have xlr entries and so have audiophile geared receivers. Of course it depends what you think when you say quality amplifiers but i would disagree: xlr definitly is present on most hig-end audio equipments... (actually any serious audiophile will turn an angry face if you dare say my audiophile AV RECEIVER).

    Re cables you'll have some fancy effects and i would clearly not recommend an xlr to rca cabling that works only if you have gain filtering on the input device. dunno if the ESS chip deserves also the rca L&R of the zidoo but if you haven't got XLR entries I would settle for with some decent RCA L&R cables
  4. Nice Monkey

    Nice Monkey Well-Known Member Beta test group

    @myzidoo: Thanks for the comment. We appear to agree. ;)

    Quality Amplifiers for me is in the 1.000-5.000 range while top end with XLR is more in the 10.000+ range (pre-amplifier plus multiple power amplifiers each with its own external PSU obviously). One may need to power on via a sequencer to avoid blowing a fuse.:p

    Very few Zidoo media player customers in that price range as when they buy such a thing it will mostly be one coming from the same brand. Cables for it alone will cost more than a Zidoo X20 Pro per cable but who cares if you have that amount of money to spend. :)
    Last edited: Aug 10, 2018
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  5. myzidoo

    myzidoo Member Beta test group

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  6. Nice Monkey

    Nice Monkey Well-Known Member Beta test group

    Updated the original post hooking up X20 Pro via XLR.
    Once confirmed if High Quality RCA is available or not will make a final update.
    Last edited: Aug 14, 2018
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  7. Nice Monkey

    Nice Monkey Well-Known Member Beta test group

    Changed the warning about XLR RMS output levels in the original post as X20 Pro was measured by Zidoo labs to output peak 2.26 V RMS being the maximum for RCA (supporting headsets). I still recommend to reduce it slightly, but no damage should be caused by it.

    This makes using XLR-to-RCA cables child-play.
    Last edited: Aug 24, 2018
  8. Nice Monkey

    Nice Monkey Well-Known Member Beta test group

    Hooked up an External USB DAC via quality RCA cables to my AMP which works perfectly. Even with the volume set at 100% there is no audible sound at the speakers even at very close range. Absolute no need for XLR (The DAC has those too but my AMP does not).

    Futeko tested RCA for X20 Pro and confirms it is connected to the SABRE DAC. Safe to use those.
    gymnos likes this.
  9. wexy21

    wexy21 New Member

    Thanks for your research in this. I'm just wondering if using the x20 pro's dac is worth the updrade of $200. Seems like it would be, but I don't think anyone has confirmed that anywhere. If it does sound better then I would hook mine up with some high quality rca cables and play the Marantz in pure audio to bypass its dac and use the x20 pro's. But if it isn't that much of a different, than I would just play the Marantz using its internal dac and keep with the hdmi.
  10. Nice Monkey

    Nice Monkey Well-Known Member Beta test group

    The SABRE 9038 DAC is a very good DAC and I can hear clearly the difference with the AKM AK4458 DAC integrated with my Onkyo TX-RZ720 receiver.
    That AKM is considered a relative good DAC but playing above all DSD the difference is very noticeable. If this is mainly attributed by the chip itself or the circuitry around it is unknown to me. Both are crucial I learned.

    But Music Player 3.0 will not output DSD using HDMI with current FW yet (if it will come?). For me the reason to go via an external USB DAC with added comercial music player APP´s.
    Frankly for me it has become a no brainier that a SABRE DAC without DSD sound support is like a racehorse without a jockey. Maybe these APP´s also find the internal DAC of X20 Pro via USB (that is how it works internally) but nobody did confirm that to me yet. Without that no way to take optimal advantage of the build-in SABRE DAC.

    The quality of the Onkyo TX-RZ720 analog amplifier section in pure/direct stereo mode is surprisingly good (Onkyo RZ-series are definitely better here than NR-series). Did also a test using the DSP by switching to other audio modes for output. This directly has a very negative effect as the analog from my DAC is then digitized first, next send to the DSP for digital processing and finally comes out via the integrated AKM DAC again. Very bad idea.
    Using HDMI stereo input occasionally use the DSP for low-pass filtering to my sub-woofer in 3-channel mode to get improved low but using the external DAC that is out of the question. The only way to do that would be a wired sub-woofer connection using power level analog filters. Older sub-woofers often had these integrated, newer ones rely on RCA filters instead (to be inserted between pré-amplifier and main amplifier).

    I do expect results with quality Marantz or other receivers to be very similar.
    Last edited: Mar 2, 2019

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