Should I buy XLR cables?

Discussion in 'Audio Hardware' started by Sebastian.Athea, Jan 9, 2019.

  1. Drewan77

    Drewan77 Forum Resident

    Location:
    UK/USA
    In my case, a switch over to XLR it has never degraded what I hear & sometimes improves it, especially when hiss or hum was present.

    On that basis I always use balanced if the option exists.
     
  2. Brother_Rael

    Brother_Rael Forum Resident

    Location:
    Scottish Borders
    Yes, buy some. I use XLR and RCA - not any difference to me, but only 0.5m lengths needed.
     
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  3. Just Walking

    Just Walking Forum Resident

    Location:
    Abingdon UK
    The way in which most consumer (and professional) balanced interfaces work is that they are for the link only. So there is a balanced driver in equipment A and a balanced receiver in equipment B. Internally both pieces of equipment are single ended. The reason that it is done this way is that the balanced driver/cable/balanced receiver is what gives the overall link immunity from ground loops/hum/buzz. And internally single ended for reasons of cost.

    You can design gear that is fully balanced throughout, but you need twice the circuitry. My phono stage works that way. There is a 19" 2u chassis for left, another one for right, and a third for the power supply. The idea is that a pickup cartridge is inherently balanced (two wires for left, two wires for right, and a ground connection at the cartridge body and arm). And I had a moment of insanity and built the thing fully balanced throughout. The rest of the system is balanced driver/receiver and single ended internally.

    I have no idea how the Oppo205 and McIntosh MA6900 balanced circuitry is configured. Without the schematics it is impossible to know.
     
  4. Classicrock

    Classicrock Forum Resident

    Location:
    South West, UK.
    I think this is system and cable dependent but it is not caused by RCA as a design. I don't get hum at all on line sources (CD) and slight hum only from phono stage with volume up. My guess is with your kit the earthing works different with XLR. I suspect some manufacturers may compromise RCA a bit when they have both connections. In reality XLR can add additional internal circuitry. Maybe the XLR cable used is better shielded? I think this recent obsession with providing XLR is just adding expense to components or an excuse to add margin.
     
  5. Just Walking

    Just Walking Forum Resident

    Location:
    Abingdon UK
    With 0.5m links, and provided that the cable shield is low resistance, there is probably not a lot of difference. Hum loops work by AC ground potential differences driving current down the cable shield, and hence generating a voltage that adds to the signal. A short single ended link with a high quality braided shield should not give a major hum problem.

    As an example, suppose the hum/buzz current is 0.3mA. For 0.5 meters of braided shield cable the braid resistance will be about 5 milliohms (Belden 8214F). Plus 5 milliohms for the ground connection at each phono (measured). So the potential difference will be 4.5uV. Referenced to 316mV consumer 0dB the hum voltage will be 97dB below the signal, and therefore not be a significant problem for most.

    If that voltage is referred to a moving coil cartridge it is much more of an issue - 4.5uV is only 36dB below 300uV from a MC cartridge. That would be a major problem!

    For balanced, by far the best construction is star quad. Have a look at a Belden spec here https://catalog.belden.com/techdata/EN/1804A_techdata.pdf . High end cables never, ever produce a detailed specification, let alone at the level of Belden.
     
    Last edited: Jan 14, 2019
  6. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Most consumer level stuff is not balanced, so it won't make a difference anyway.

    Short 0.5 to 1.0 meter interconnects are short enough, that you won't have a hum anyway.
     
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  7. Just Walking

    Just Walking Forum Resident

    Location:
    Abingdon UK
    Hey - you all by now know that I am a firm proponent of balanced. But this post is right. Provided that (a) potential difference between safety grounds is low at each equipment and (b) cables are short with low resistance screens and (c) the ground connection at the RCA screen is clean and low resistance and (d) the overall set up is simple, you can get away with single ended.

    The problem arises for those who do have a buzz problem. Diagnosing the root cause can lead to days or weeks of frustration.

    A bit of a lottery, alas ;-)
     
  8. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Most equipment doesn't have balanced connections anyway, RCA connector's only.

    They generally work fine, for what they are designed to do.
     
  9. CoolJazz

    CoolJazz Forum Resident

    Location:
    Eastern Tennessee
    Got it! OK is good enough for you.

    CJ
     
  10. tmsorosk

    tmsorosk MORE MUSIC PLEASE

    Location:
    Alberta Canada
    A lot of the lower priced equipment is not balanced so XLR's will not make a difference except maybe lower the noise floor. But in a fully balanced system the improvement can be well worth the effort.
    One thing I like about XLR's is they lock-in so if you have beefy cables they won't work there way out.
     
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  11. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Yep, good enough for me and every manufacture of home audio gear that I own.

    Not a single preamp or power amp that I own, that is not intended for professional sound applications, tube or solid state, has XLR connectors.

    And, I don't even like RCA's and would prefer to have all gear to have balanced XLR's.

    If you have short runs and do not have hum, then you don't need XLR's.

    XLR's are intended to reduce hum for long interconnect runs.

    They don't do anything "magic" in a home audio system.
     
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  12. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Yes, the connection is held in place by the lock. When you remove an XLR connector, you release the lock and the XLR connector pulls right out.

    You don't have to worry about a tight gripping RCA plug, pulling the RCA jack apart.
     
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  13. tmsorosk

    tmsorosk MORE MUSIC PLEASE

    Location:
    Alberta Canada
    That's a good point too. Although many of my heavy RCA's seem to be half way out when I check them, probably my fault as I'm always goofing around with the stereo components.
     
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  14. Bill Mac

    Bill Mac Forum Resident

    Location:
    So. ME USA
    You can spin it any way you wish. But the complete elimination of noise in my system clearly shows that there is a benefit for using XLR connections with home audio equipment. I've read a number of accounts where the use of XLR connections has reduced or eliminated noise in home audio systems. So if you think that the total reduction in noise in one's system is not beneficial I don't what to say.

    I use Signal Cable Analog 2 XLR and RCA cables. So the quality of the cables are very similar in build quality. Not only do using XLR connections provide the obvious benefit of noise removal in my system. The locking aspect of XLR connections are far more secure than when using RCA connectors as well. So having a better locking connector that is easy to apply and remove without putting strain on a components inputs/outputs is not a benefit? I'm not sure why you say there is an "obsession" with XLR connections. I look at it as once again having the advantage of noise reduction and far better connectors.

    If you think there's no point in using XLR connections in a home audio application that's cool with me. But trying to make the case that there are no benefits to using XLR connections with home audio components then you are incorrect.

    One "obsession" I do have is trying to have the best components and associated equipment that I can afford. So if buying components with XLR capability and taking advantage of the benefits associated with those connections is an "obsession" so be it :).
     
    Last edited: Jan 14, 2019
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  15. Frost

    Frost Forum Resident

    Location:
    Chicago
    I have a degree in EE also, that I admittedly dont use as I have been a professional audio engineer for 20 years. I do have a good basis for understanding circuits and actual use. Theres a lot of instances where pin 1 needs to be lifted in a balanced connection between 2 pieces of equipment because a ground loop is created. If balanced is immune from ground loops why do DI boxes have ground lifts?
     
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  16. SandAndGlass

    SandAndGlass Twilight Forum Resident

    Never really thought about it, but it would not be that much different than a ground lift switch anywhere else?
     
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  17. Frost

    Frost Forum Resident

    Location:
    Chicago
    The only real difference is that a ground lift in some locations is dangerous (ac lines) and within a di box is slightly different because the rest of the signal is buffered by a transformer which lifts physical connections on its own.
     
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  18. Just Walking

    Just Walking Forum Resident

    Location:
    Abingdon UK
    Because pin 1 has been implemented incorrectly via signal ground. Pin 1 has to be taken directly to the chassis by the shortest possible link. I use a solder eyelet on one of each XLR's securing screws and take each pin 1 to its adjacent screw.

    If you do it any other way, you get hum injection into the audio ground, and need the sticking plaster of a ground lift.

    If pin 1 is taken directly to chassis at each end of the link there is no hum. Period.
     
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  19. TheVinylAddict

    TheVinylAddict ___The Enforcer___

    Should one try XLR cables? Well, IMHO, given the fact that a nice set can be had that won't break the bank, I say it's worth a try and make your own choice and see how it works with YOUR particular setup!

    I will say I read for a long time that the balanced inputs on the Parasound A21 were worth a shot --- then I finally tried them and I was sold. But it really depends on your gear and setup, there is not a guarantee it will be an improvement.

    I read for so long the prevailing wisdom that it would NOT improve SQ, that they were mostly needed for long runs, EMI, etc... but I am glad I tried it. Today, I use them from my preamp to amp and I noticed improvement overall.

    The Parasound A21 and other manuals, among many other user guides for other gear, say that if you have a choice, use XLR / balanced... while not a guarantee of SQ improvements, I am glad I took the advice of those that made the Parasound amps and tried them.

    Just to be clear - I am not making a definitive statement that XLR is better than RCA - please read carefully and note how I qualified my response that it depends on many factors, including if your component design is actually balanced and not just wired to the RCA outputs.... so many factors in audio and always depends on what gear you are attempting to integrate.
     
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  20. Frost

    Frost Forum Resident

    Location:
    Chicago
    If the ground potential between the ac power feeding two pieces of gear is different, then there will be a buzz. Thats what a ground loop is. If there were a simple fix such as soldering to the xlr securing screw, would not every audio engineer in the world do this? Would there not be far fewer 60hz buzzes in audio to fix? Why do millions of engineers still use ground lifts when needed when a simple solder eyelet could fix it all? Meanwhile those of us in the field pick up buzzes from our connections to the video truck outside, from running next to 4/0 power for 100 ft, or just from a building with grounds run far enough apart to find some potential voltage difference.
     
  21. Kristofa

    Kristofa I dream of wires

    Location:
    Eugene, Oregon
    My vote is to buy some. Why not? You don’t have to buy fancy ones to hear a difference if your system lets you hear a difference.

    I run Morrow MA-1 and some none-too-fancy XLRs that seem solidly built and likely came from Guitar Center. I use both between my Oppo UDP-205 and Parasound HINTO. This allows me to toggle back and forth on the fly. Attempting to adjust for the increased gain of the XLRs, I would say (in my system), the XLRs sound tighter and clearer...but it also has decreased depth compared to the loosy-goosy Morrow MA-1s. I usually listen using the MA-1s, but when my ears want to hear it differently, I try the XLRs. Sometimes it is an improvement, sometimes I just switch back. It is as hard as the press of my remote.
     
  22. Helom

    Helom I'll take the monkey coffins

    Location:
    U.S.
    Use a well-designed Japanese amp (Sony, Yamaha, Denon, Marantz) and noise is a total non-issue. You'll have a dead quiet system, regardless of using XLR or RCA. Amps and amps alone are to blame for 90% of noise problems in domestic audio.
     
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  23. TheVinylAddict

    TheVinylAddict ___The Enforcer___

    The only issue there is that although the companies you mentioned did make "well designed" gear in some instances, they also made gear to meet much lower price points over time, and it becomes tougher for many to draw that line to where the "well designed" crossover and price point begins or ends.

    I can offer a ton of Japanese Denon, Yamaha, Marantz and Sony amps that are not up to the level where noise is not an issue, and mainly due to the fact they were appealing to a much lower entry / budget point. So it's not as easy as offering brands without getting specific on actual models. If only it were that simple as to just choose a brand name.

    Then what about Accuphase, Quad, Levinson, McIntosh, Krell and many others? Would they not be maybe other or in some cases better examples of well designed gear? I know many that think Accuphase produced gear that surpassed any of the companies mentioned, and I am a Yamaha enthusiast.

    Point being it's not a black and white issue, can't be divided by brand.... it is a case by case, component by component thing. Accuphase was an early adopter of XLR, and amps from the mid 80's had XLR inputs / outputs which are truly balanced, long before other more mainstream companies even thought about them. But even in those cases, some were well executed on XLR, others were not.

    XLR - try it before you make any definitive opinions. Depending on brand, model or other factors you might be surprised. Not all equipment is going to give the results you desire just because it offers an XLR port, but in other cases the results might be positive. I have many components in multiple systems, and I employ both XLR and RCA interconnects with varying success. I also own gear made by Yamaha, Denon, Parasound, SOny and many other companies - both vintage and new. As with anything audio, one or two sentence declarations or assertions rarely cut it, the devil is always in the details.
     
  24. Just Walking

    Just Walking Forum Resident

    Location:
    Abingdon UK
    With unbalanced, of course an AC voltage at 50/60Hz and harmonics flows in the cable shield you get hum and buzz. But with a high quality balanced cable, with either a single 95% coverage braided shield, or a braided shield *and* a foil shield, and the receiver has a decent CMRR , you won't get hum.

    (Oddly enough you don't need a screen. A screen does absolutely nothing to attenuate magnetic interference. It only deals with interference from electric fields)

    But the thing that gives CMRR is how a receiver handles imbalance at the driving end. CMRR works like a Wheatstone Bridge. The upper arms are the two output impedances of the drivers, and the lower arms are the common mode impedances of the receiver. Either all of these have to be very high tolerance, or the common mode impedance of the receiver have to be both very high and matched to 0.01%.

    Look at it this way. Suppose the receiver is the regular instrumentation amplifier with input resistors of 10k. Apart from the fact that the differential mode impedance is different for both signals, the common mode impedance is only 10k. Even if those input resistors are perfectly matched, a driving end impedance mismatch of 10 ohms gives a maximum CMRR of 66dB. If the 10k receiver resistors are not precisely matched and trimmed they also degrade the CMRR further.

    The only company which makes this explicit in the design is That, with the 1200 InGenius series of balanced input stages. The topolgy uses laser trimmed resistors, and CMRR bootstrapping to give a CMRR at 60Hz of 90dB with a drive impedance mismatch of 10 ohms (1% tolerance on the usual buildout resistance of 1k), falling to 85dB at 20kHz. The common mode impedance is 10M, 1000 times higher than the often-used instrumentation amp, and are precisely matched.

    The only other way of getting those sort of figures is using a transformer input. These have similar, or higher CMRR. The only reason that the That devices win is that they are a couple of orders of magnitude cheaper than a high quality transformer.

    The quality of the cable also has an impact. There is a phenomenon called Shield Current Induced Noise, SCIN: Shield Current Induced Noise . This tends to be a higher frequency problem, and can lead to RF pickup. Foil screen with a drain wire is worst because it distorts the magnetic field cancellation at the signal wires. Braided screen star quad from Belden https://catalog.belden.com/techdata/EN/1192A_techdata.pdf has high performance in that regard.

    Regarding hum immunity, the above cable has a braid resistance of 0.71 ohms per hundred feet. A typical shield current with widely different power sockets will be 100mA. That is 71mV of shield voltage drop. Even in the ridiculous thought exercise of 100% of that coupling to the cores as a common mode signal, it would be attenuated by 90dB by That's chip, and result in a hum voltage at -110dBu and buried in the noise. In practice way below 1% of the shield voltage will couple to the signal wires and will be a completely insignificant problem. And you can run a star quad cable like that right next to power runs without any induced hum problem.

    So - I still contend that a ground lift is a band aid. Manufacturers put one on because even if their product is perfectly implemented, they have no control over what the engineer is going to wire it to, and with what quality level of cable.
     
    Last edited: Jan 15, 2019
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  25. Helom

    Helom I'll take the monkey coffins

    Location:
    U.S.
    It's certainly not exclusive to those brands, but I've yet to come across a nosiy, non-vintage example from any of them.
     

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