Balanced cables


Do different brands/levels of balanced XLR ended cables going to and from differentially balanced components make a difference?
stringreen
Yes. Most of the aspects of cable design that affect performance apply to balanced cables just like single ended, you just don’t have to worry about directionality 😉 assuming the manufacturer got this right in construction.

Seriously however you will hear differences as you move among balanced cables just as with single ended
In many and I suspect the majority of cases, yes. In some cases no. It depends on the designs of the components that are being connected.

For the design characteristics of the interconnected components that are necessary to minimize and quite possibly eliminate the sensitivity of a balanced interconnection to cable differences, and for what I consider to be compelling proof of that contention, see the post by Ralph (Atmasphere) near the beginning of this thread. Also see the follow-up questions I presented to him later in the thread, and his response.

Regards,
-- Al

While I have nothing to disagree with in the thread @almarg refers too the entire discussion is at a fairly basic/EE theory level in the cable controversy canon. To whit if you believe cables are sensitive to external vibration, interference from the surfaces they are resting on etc etc then balanced cables are just as subject to this as unbalanced. Certainly I’ve found that to be the case running 30’ lengths of WEL signature balanced to my power amps.  If you don’t believe any of this then be you can be happy with your long runs of studio grade balanced wire.
Yes and no..Yes only if the signal path circuit is intentionally designed  by the engineer in an amp or preamp to be wired better to the XLR than the RCA connector. I read an article about ten years ago of an interview with James H. Cannon, the inventor of the XLR connector. Shortly after he added a lock on the three pin connector he passed away in 1950. I believe the interview was in 1949. He was asked in the interview if his XLR connector results in better sound than the RCA connector which was invented by RCA around 1942. He said "No..thats not the reason why I invented the connector". He explained it was only designed for better grounding with the ground pin to eliminate feedback when your running very long lengths beyond 20 feet to a hundred feet or more. He continued saying that if you have short lengths below 20 feet there is no feedback using an RCA to interfere with the signal and no difference in sound quality. Beware of snake oil.
Yes, XLR cables can and do sound different in many home audio applications. Same as RCA cables.
Though if you cannot hear a difference, then don't worry about it.
elizabeth-that is partly true but only to the extent on how the high end component for in home use is designed. As I already stated a designer of amps and pre-amps can intentionally wire the signal path to an XLR to make it sound better than the RCA outputs, done for the purpose if one plans to do long cable runs in home beyond 25 feet. David Belles, who designs some of the finest solid state and tube pre-amplifiers in the world, does not use any XLR inputs or outputs on the back of his solid state or tube preamps, and they are quiet as a tomb. You will find single ended XLR inputs on the back of his top amps next to an RCA input only for the purpose of using the amp for very long cables in large environments. An XLR connector is just a connector, thats all. Its not a buffer or a processor and has nothing to whatsoever effecting the music signal. Its only function is to ground noise
feedback in a cable. It reminds me of the snake oil of many speaker companies selling models with three sets of binding post on their full range models. Even Spendor, my favorite British speaker company laughs at that nonsense as well, all their models, including their top flagship model, the D-9 uses only single pairs of binding posts.
Is this the same Stingreen who knows all about VPI gear, turntable set-up, and Quicksilver gear, the same Stingreen who years ago gave me specific advice as to how to upgrade the coupling caps on my ARC VS110? :-)
I was a bit surprised to see that you have expressed your disdain for Cardas cables. My opinion/experience is that as the quality of the electronics goes up and assuming that the design is truly balanced, than yes, there are marked differences among XLR cables. I totally understand the viewpoint of cable-skeptics because the differences are on one hand subtle and yet on the other, they can be huge. One analogy is a photograph that is ever so slightly out of focus vs. the same photo that is. As the quality of the gear increases, the perception of that perfectly in-focus image is better appreciated. I now own an ARC Ref 6 and ARC Ref 150se and I tried a variety of XLR's between the pre and amp and also various speaker cables and with each, I heard vast differences. The Ref 150se doesn't even have single ended inputs. ARC stresses in their manual that the quality of the XLR going into the Ref 150se is critical and they were telling the truth. I ended up with Cardas Clear Beyond XLR and Cardas Clear speaker cables and could not be happier. 
When I first upgraded my electronics, I read all I could about the opposing views on XLR's and saw the posts of those who say that with balanced cables, the differences of various brands are minimal and suggesting that Mogami Gold is all one needs because that is what is used in recording studios. This is one of those things that sounds good on paper but does not fly in reality. I started out with those Mogami Golds and they were the sonic equivalent of that girl that your mom says has a "very nice personality". A $600 pair of Morrow MA-6's were better, but the sound was etched, tone and timbre sounded "off", and my music was coming out of two boxes. A pair of top level Harmonic Tech's on loan from a dealer were very nice but not quite what I wanted. With the Cardas, tone and timbre are spot-on, I get the chills on the back of the neck that I never came close to getting with any of the other wire, my speakers disappear in my room, and everything is in focus. 
Fsonicsmith, as a point of information ARC line stages and preamps do not meet the criteria Atmasphere cited in his post that I referenced that would minimize or eliminate sensitivity to differences between balanced cables.  Certainly, at least, with respect to his criterion no. 4:
Atmasphere 3-22-2013
...  4) the output of the preamp should be capable of driving a low impedance load (2000 ohms or less) without loss of voltage, without increase in distortion and without loss of bass (this is the other big area where high end audio preamps have a problem, and also results in cable sensitivity).
ARC's recommended load for nearly all of their line stages and preamps is a minimum of 20K, and in some cases a minimum of 60K is indicated as being optimal.

So when "ARC stresses in their manual that the quality of the XLR going into the Ref 150se is critical," as you indicated, they are indeed "telling the truth."

Regards,
-- Al
 
Al, I always read your posts with interest. You clearly know far more than I do about technical aspects of electronics. I can not read a schematic and never understood concepts of loading as it pertains to amps or phono cartridges :-). With that spirit in mind, I think I know this; say what you wish about ARC, but their 40 year history of building top-tier preamps is incontrovertible. I am going to venture a guess that while Ralph is most likely correct, there are also drawbacks to designing a preamp that is capable of driving low impedance loads. Even if it were true that with certain preamp designs, the quality or "pickiness" of the XLR choice were minimal, is that attribute a "freebie" without trade-offs? I can't help but think of the relatively high negative feedback employed by ARC in the Ref 150se. It's a buzzword in the industry that "no negative feedback" or "minimal negative feedback" is and of itself a mark of distinction and superior sound. Again, I only know that I am getting hair raising chills on the back of my neck and total immersion in the music with the tonal density I had hoped for and without any perceptible bloat, with a wide and deep soundstage that was not critical on my wish-list, but a happily accepted bonus. As with many hobbies, there are certain buzzwords that tend to predominate as accepted truths, but the reality is that "it all depends". 

I have an all Ayre system (with Vandersteen speakers). I’m hearing a kind of metallic sound from the system which I’d like to pin down. As I stated above, its totally balanced from cartridge/CD player through the amp. I even removed the tweeter and mid from the boxes, sent them to Vandersteen who deemed them in excellent health. A while back I tried different XLR cables which had a minimal effect on the total sound....but that was awhile ago (Wireworld top of the line). I’m sure my hearing has changed (I’m a violinist and sit next to the piccolo) and just thinking about change. My amp is about 14/15 feet from the preamp, and no one has that length to try without a firm purchase.......still thinking. Re: Cardas......no luck with that brand. Colleen Cardas told me that it probably needed more time to break in (months?)....although I haven’t heard their newest offerings.
BTW-There is no such thing as a "balanced cable". That term implies that an XLR/Cannon connector was only designed to be used with fully balanced left/right channel audio components which is very misleading and completely false. There are solid state components that are fully balanced with both RCA and XLR connector's. The inventor of the XLR never used the term "balanced" for his connector. When the very first stereo receiver was invented by Sydney Harman in the 1950's, the Festival 1000, it was a fully balanced design in twin cabinets with the left channel in one cabinet and the right in the other. with a control panel on the front of each unit. A classic dual mono design. The unit had RCA connector's only. The term "balanced" was a label put on XLR cables by Audiophiles in the 80's. You can label an RCA cable as well as a "balanced cable" if its used between fully balanced components. 
Fsonicsmith, thanks. I essentially agree with everything in your post above. There are always myriad tradeoffs in a design, and the net result of those tradeoffs often will not conform to commonly stated paradigms.

For example a major reason, and perhaps the most major reason, for ARCs 20K minimum load recommendation is their use of a coupling capacitor at the outputs of their line stages and preamps, which of course is very commonly done in tube-based line-level components, and which among other things causes a substantial rise in output impedance at deep bass frequencies. And while that effect could be minimized by simply increasing the value of the capacitor (i.e., the number of microfarads), doing so would most likely increase the sonic colorations introduced by the capacitor itself, and/or result in the capacitor being a larger and potentially impractical physical size.

And an alternative approach that is used in some tube designs, using a transformer instead of a capacitor, certainly can have tradeoffs of its own.

Regarding feedback, yes, ARC power amp designs tend to use more of it than many and probably most high quality tube amps from other manufacturers. Consequently they have lower effective output impedances and higher damping factors than those other amps, which in turn can be either an advantage or a disadvantage or neither depending on the particular speaker that is being used. And the downsides feedback can potentially have with respect to the intrinsic sonic character of the amp will depend on numerous other aspects of its design.

As you aptly summarized, "it all depends."

Stringreen, I have no particular knowledge regarding the sensitivity of your Ayre components to cable differences. An experiment that could possibly be informative, though, would be to **temporarily** put a cheater plug on the amp’s power cord, to defeat its safety ground connection. If that results in a perceptible sonic difference it would suggest that ground loop effects may be present, which in turn can result in sensitivity to cable differences especially when the length involved is long. Note Ralph’s criterion no. 2 for minimizing the sensitivity of balanced interfaces to cable differences, in his post that I referenced earlier:
Atmasphere 3-22-2013
... 2) Ground is ignored- the signal occurs only between pin 2 and 3 (this is where most high end audio preamps have a problem- as soon as there are signal currents in the shield of the cable, the construction of the cable becomes critical).
Regards,
-- Al

Stringreen, I tried a 7 meter Cardas Parsec which from day one was thin sounding. And yeah they said 'it needs to break in'. After a month (and I listen all day every day to music) It was still the same story.
I returned it as unsuitable. I went eventually with a 7 meter XLR Kimber KS1116 and from the moment it was in the system all was good.
So I have to say (and yes I am highjacking the thread a bit) Sometimes folks need to realize break-in can be used as an excuse for stuff which just does not work.
Now IMO the 1 meter Cardas Parsec XLR are wonderful, just they fail when it is a lot longer. (My theory is the small gauge of the wire they use in the Parsec is just too thin in the balanced configuration at long lengths, but is fine for short one meter XLR  IC)

And I really wanted to just put a note in to Stringreen, so forgive my taking the thread off topic.
Stringreen, I, too, own Vandy (Treo's) and am currently using the Atma MP-3 and MX-R amps (non Twenty).
Ralph sold me a set of XLR cables (25foot) to go from the preamp to his MA-1's. They weren't expensive and I find them to be very listenable (no shrillness). 
Perhaps you should give him a call, and get his take on this. His take, if I recall correctly, is that if the equipment is designed properly (like his and Ayre's), then an XLR shouldn't affect sound quality.
Bob
I have an Ayre preamp and an Ayre CDP and the quality of XLR cables most definitely do affect the sound character of my system.

Dave
gdnrbob.....who is Ralph?
Depending on which amp and speakers I have setup, there is a definite preference for the XLR cable between preamp and amp.  The cable chosen is a different brand between the two setups. The remainder of the systems cabing remains unchanged.

Yikes, that long of a run will be really pricey for a quality cable.  The hard part is there is not a best cable period.  It will take time and a few candidates to find the right one for you and your system.  Maybe the Cable Company has some long runs of different XLRs you can try.

You will get everyone’s version of the best cable, unfortunately that won’t help you one bit.  I won’t tell you mine.

Question, is this a new problem or something that’s been there awhile and finally bothering you to the point of doing something about it?
dlcockrum-Went to the Ayre website to check the gain specs on the Ayre preamps. Its very common that companies making preamps with both single ended and XLR outputs will adjust the gain higher to the XLR and lower to the single ended outputs. The Ayre KX-5 has a maximum of only 4 db's to the single ended and 10 db's to the XLR's which is a big difference with short runs. This is why the XLR "sounds better" since the gain is much stronger than the single ended. If the single ended gain was at 10 db's and the XLR at 4 db's then the RCA output would sound much better. This has nothing to due with the type of cables, just higher gain that makes a difference. Doesn't take rocket science to figure that out.
Audiozen,

My intent was to state that I hear significant differences BETWEEN different XLR cables, not between the SE connections and the XLR connections.

I am no rocket scientist (and neither are you) but I am well aware of the gain differences between SE and differentially balanced topologies.

Dave
OMG I am old enough to know better than to jump into this lol but. After years of working in studios all I have to say is that none of the music ever recorded was done using anything but some form of Belden or equivalent type cable and connectors like switchcraft  or similar. How some "ulta" type interconnect could add or reveal musical qualities that were never in the original transfer is up to you to figure out. If you do hear a difference and like what you hear do buy the product. We all have our own experiences.

jerroldls-Well said...

dlcockrum-no offense. I'm sure your familiar with, as most Audiophile's, of gain levels in components. I simply was applying common sense. Wire is wire, and all it does is transfer music signal. Its how the component is configured to the outputs by the designer where the circuit design and gain levels can sound better at one output over another regardless of the cable.
I agree that simply recommending the cable that worked for you is senseless. However, it is very unfortunate that this thread has to once again devolve into the debate as to whether wire is wire. For those that believe that all wire is wire, fine. Maybe with your system, wire is indeed wire, with no perceptible differences and you could put ten listeners in your room and all would compare notes afterward and all agree. And please don't read some intent to malign your system when I say that. It is always possible that in the culprit for Stingreen's perceived harshness with his Vandersteens have nothing to do with cabling and more importantly, can't be successfully addressed with cabling. But one thing is beyond debate and that is this; in some systems and for some people different cables sound markedly different. I say this in the context of IC's and SC's only. Let's leave PC's out of this. Stingreen, I usually read your posts. IIRC, you've been running Are and Vandies for a while now. When did the perceived metallic sound start and what-that you can think of-changed in your system when the metallic sound was first noticed? Absent some change that you purposefully made, it would seem that there are only two possibilities; a change in your electrical grid or a new sensitivity on your part to something that was always there. 
Elizabeth said "sometimes folks need to realize break-in can be used as an excuse for stuff which just does not work."
Bingo!  If a cable is not acceptable right out of the box then it most likely never will be.  I have used tons of cables in my system and break in for me is real but not jaw dropping.
"For those that believe wire is wire, fine"...now let me see, if I take an interconnect cable and slice the side open, guess what, theres copper wire inside. Amazing!!! it must be wire!. You can pretend its the golden hairs from the scalp of Goldilocks all you want, but its just wire. You need to take off your rose colored glasses. And to ignore the post above by an expert recording engineer is disingenuous and disrespectful, acting like the professional recording industry is inferior and has no clue what there talking about because your an "Audiophile" and your "opinion" is much more important then recording engineers or the broadcasting industry because you read "high end magazines" and bow down to the demi-god reviewers who are taking you for a ride. Back in 1998 I purchased a pair of Paradigm Active 20 speakers and a BAT Vk3 preamp. I decided to buy an pair an eight foot of MIT interconnects with the box on the cables. They retailed for $1000.00 and Audio Advisor was selling them at 40% off. Hooked them up and a week later I was disappointed with the sound quality and on a whim, decided to use the very cheap 20 ft. stock pair of IC's that came with the speakers. I removed them from the box, hooked them up, put on a disc and was blown out the window. Completely shocked. The differences were not subtle, a big major difference. Sounded like a completely different speaker raising the performance to a whole new level I wasn't prepared for. I said to myself, "Whats wrong with this picture?" and called Paradigm and spoke to one of their engineers. I asked how much are your stock IC's that came with the speakers? He said $20.00 a pair. He asked me the model of the MIT's and said that IC will not work because its a high capacitance low resistance cable. Our 20's are designed to use with low capacitance high resistance IC's and  mentioned that components from different companies worked best with IC's that match the mathematical values of their designs, and has nothing to do with the price of the cable. The Cable Company in Ohio has complete charts of those mathematical values from each high end company for their amps and preamps. If you go into a broadcasting-recording supply house and buy inexpensive cable that matches the value numbers of those components you will be blown away at the performance of your gear. Quit being a sheep. Quit being a lemming.

As W.C. Fields said.. "Theirs a sucker born every minute"
@audiozen

Many folks simply want to believe cables make a difference - many because they spent a quite considerable portion of their budget on nonsense tweaks.

You will never get these same folks to ever admit they were fools or suckers as W.C. Fields put it.

Furthermore, the mark up on cables and silly fuses and silly contact goo is in the thousands and therefore an army of unscrupulous sellers and resellers will rush to attack anyone who says “the emperor has no clothes”.

Worse, if you look at the sales supporting the economic model of this website you will see a significant percentage is in nonsense tweaks - so moderators are not going to lift a finger to kill a lively business of parting fools from their money....

Nonsense tweaks are to audiofools as expensive rejuvenation creams are to the vain and superficial...
""For those that believe wire is wire, fine"...now let me see, if I take an interconnect cable and slice the side open, guess what, theres copper wire inside. Amazing!!! it must be wire!. You can pretend its the golden hairs from the scalp of Goldilocks all you want, but its just wire. You need to take off your rose colored glasses. And to ignore the post above by an expert recording engineer is disingenuous and disrespectful...your an "Audiophile" and your "opinion" is much more important then recording engineers or the broadcasting industry because you read "high end magazines" and bow down to the demi-god reviewers who are taking you for a ride...Quit being a sheep. Quit being a lemming.As W.C. Fields said.. "Theirs a sucker born every minute""  

You missed you're calling you should have become a fundamentalist preacher oh wait you already have become a preacher good luck with your faith and in attracting a flock of rapt followers..
Sometimes folks need to realize break-in can be used as an excuse for stuff which just does not work.
Half of break-in is people's ears getting acclimatized to the new and different--though not necessarily better--sound of a new component (and I include cables in the category of components).
The biggest load of hyperbole I ever came across years ago which I still laugh over today is how Harmonic Technologies would tout over their "cryogenic" process to their copper wire to preserve and prevent the crystal cell pattern from breaking up, preventing sonic degradation of the music signal passing through the wire. What a bundle of Barnum and Bailey snake oil. All the sheep bought into that like a moth hitting a light bulb.
Cryoing wires does change the wire.
Same as cryoing drill bits and racecar engines. Those folks do it to have stronger parts. The metal IS changed near absolute zero. No bs.
I personally do not like the change in sound of some cryoed parts. but no question that there is an actual physical alteration in metal from cryoing.
As fate would have it many if not most high end cable manufacturers employ cryogenics for their cables and power cords. They wouldn’t be able to compete otherwise. The really smart ones like Audioquest control wire directionality for cables and power cords, even stranded cords. The connectors are smoother after cryo, kinda like the way the finger action of cryod trumpet keys is a lot easier and smoother.
Re: Cryo'd metal......pro musicians I know cryo'd their trumpets, trombones, sax's etc.  to find (what they tell me) is a more "pure" sound.
Recording studio's and recording engineer's could care less about 
hypo/cryo nonsense. I find it amazing that we all buy our vinyl and CD's 
from companies whose master tape CD's and master tape vinyl sound fabulous and guess what, just about all of these studio's are using budget wire from Belden, Canare and Mogami for recording and mixing. Audiophiles love to speculate that they are more "technically" proficient and superior to well educated recording engineers and the recording industry, since they got their education from high end magazines, but the reality is Audiophiles live in denial and most do not have the technical education on the level of the best recording engineers and studios. Give me a break. 
Dean of Audio Engineering school commencement speech, excerpt.

It’s been an eventful two years and now the time has come to say goodbye. Many of you sitting here today will go on to bigger and better things. The rest of you will become recording engineers. 

🤡
Golly geoffait-I had no idea that a recording engineer was such a low level profession. I wonder, is that a better professional career than a dishwasher at a PHO restaurant? What an insult.
  audiozen
... I had no idea that a recording engineer was such a low level profession.
Actually, the term "recording engineer" is a misnomer, because real engineers - such as electrical, electronic, civil, structural - are licensed and degreed professionals.

A "recording engineer" is really a "recording technician." They are not truly engineers unless, of course, they've actually earned that designation. Most haven't.
We are now down to the point where both side are just spewing...
Time for a break.

Uh, oh! It’s the heat! Everybody scatter! 😬
Do different brands/levels of balanced XLR ended cables going to and from differentially balanced components make a difference?
They shouldn't. The question really should be- does the equipment used support the balanced line standard. If no- then cables make a difference. If yes, the cables won't affect things even in long runs.

I feel compelled to set the record straight in a couple of areas:

BTW-There is no such thing as a "balanced cable". That term implies that an XLR/Cannon connector was only designed to be used with fully balanced left/right channel audio components which is very misleading and completely false. There are solid state components that are fully balanced with both RCA and XLR connector's. The inventor of the XLR never used the term "balanced" for his connector. When the very first stereo receiver was invented by Sydney Harman in the 1950's, the Festival 1000, it was a fully balanced design in twin cabinets with the left channel in one cabinet and the right in the other. with a control panel on the front of each unit. A classic dual mono design. The unit had RCA connector's only. The term "balanced" was a label put on XLR cables by Audiophiles in the 80's. You can label an RCA cable as well as a "balanced cable" if its used between fully balanced components.

The above post is 100% false. The Festival 1000 employed single-ended circuits (combined with a Williamson-style power amp section); thus it used RCA connections. RCA connections are not balanced- the shield connection is used to shield the 'signal' but in reality the shield is important as it completes the circuit. In a balanced connection the shield is ignored (unless the equipment in use does not support the balanced standard, AKA 'AES File 48'). The phone company originally used balanced line connections in the 1950s, which is what made trans-continental phone calls possible and the term 'balanced' was used way back then.

As applies to audio, the balanced connection is used to minimize the effect of the interconnect cable. You would think audiophiles would jump on this like a hobo on a ham sandwich! But I have been surprised at the amount of push back over the decades since we introduced the idea. Regardless, if your gear actually supports balanced operation as intended, the cable isn't going to be something that requires audition- its simply going to work without editorializing.

Since I mentioned the balanced standard, here are the important bits again for those that did not read the thread Al linked above
1) the source will be low impedance able to drive 2KOhms with no worries
2) the signal is pins 2 and 3 of the XLR connection, and travel as a twisted pair within the cable
3) ground is shield only and is ignored by both the source and at the receiving end

Its that last bit that gets so many in trouble- if it is not followed, then the shield (just like with single-ended operation) becomes part of the overall sound and you start to 'hear' 'differences'. ARC as pointed out does not support the standard, as they have no preamps that can drive 1 or 2Kohms and their outputs (pins 2 and 3) occur with respect to ground (pin1) rather than with respect to each other.  With such a preamp the choice of cable will be important- ***which means the point of balanced line operation is defeated***, even if the preamp is internally balanced!

We got around this problem with a floating output that ignores ground. In the old days this was done with an output transformer (usually set up to drive 600 ohms which is the old balanced standard input impedance); we are the OTL guys so we did it OTL; our outputs are balanced and direct-coupled (thus also eliminating the output coupling cap; the latter being used often indicates that the circuit does not support the standard...).
Thanks Atmasphere    ...that's exactly the information I was looking for.  I'm hearing a metallic sound that's driving me nuts (mids/highs)...and am looking for the culprit.  I tried everything including removing the drivers from my Vandersteen's ...Richard said they were fine.  My Ayre dealer thought it was the silver in the cables, but you nullified that idea. ...thinking it just may be my ears.....  
The ferrofluid probably dried out in your midrange and tweeter. This happens after as little as 2 years depending on use. That would explain the metallic sound. Are you the sole owner? It doesn’t take much to damage those drivers - a bit of clipping even at modest power will heat the voice coil up immensely...
atmasphere-. Having been a Gon member for 15 years under two different handles, this is the first thread I jumped into on the subject of cables. Maybe where the confusion lies is that just about all high end mono amps have both RCA and XLR inputs as well as dual mono stereo designs in a single chassis. So if a balanced dual mono/stereo preamplifier has both XLR and RCA outputs, and both outputs from XLR or RCA or moving signal from a separate mono channel for left and right, then in essence their both balanced cables doing the same thing. Interconnects are nothing more than ground connectors. As I already pointed out, no one called XLR cables balanced cables for almost forty years until the 80's when dual mono/stereo components were on the rise having the option of XLR or RCA outputs. If XLR cables were invented in the 80's for the sole purpose only to use with high end dual-mono components, then technically it would be a balalanced cable only, not a cable that was given the nickname "balanced" due to its great ground properties which works best with noisy components especially noisy tube amplifiers. Speaking of tubes, don't mean to get off subject stringreen, but this will benefit you as well, and that is a tube device I bought last spring at the time I purchased my Rega, Sony SACD, Ascend Acoustics system.
A tube buffer made in London that blew me out the window, its that good.
Its from the I-Fi company. Its called the Ifi-iTube2, and its pure magic and only cost $375.00. I purchased mine from Amazon. It uses a single GE-NOS 5670 tube that has an average life of 100,000 hours. It has three settings for three different sonic signatures. Classic tube, single ended triode, and push pull. It also has a bass boost setting, increase bass below 40hz by 6 db's, and 12 db's below 80hz. If your speakers have a problem with a narrow sound field, it has a 3D setting that will widen your sound field by thirty degrees. If your currently a solid state person and were into tube gear in the past and got fed up with inefficient tube amplifiers that waste energy drawing a constant 100 watts from you ac outlet at idle and all the maintenance hassles, then the iTube2 is the answer to your prayers. I had mine patched between my Sony SACD player and my Rega integrated set on classic tube. All the tube magic is there. Heres the link to the iTube2.

                                        
                                   www.ifi-audio.com




So Ralph, based on your engineering knowledge, why would ARC make those design choices? Can you hazard a guess as to what the most likely reasons would be? My experience tells me that there must be trade-off considerations-at this level of audio, there always are. 
Audiozen 2-27-2018
... just about all high end mono amps have both RCA and XLR inputs as well as dual mono stereo designs in a single chassis. So if a balanced dual mono/stereo preamplifier has both XLR and RCA outputs, and both outputs from XLR or RCA or moving signal from a separate mono channel for left and right, then in essence their both balanced cables doing the same thing.
They are both doing the same thing in that they are conveying, or at least attempting to convey, the same information from one component to the other. But they are doing it in very different ways, with results that are unlikely to be identical.

A balanced interface by definition has two signal lines which have the same impedance between each of the signal lines and ground, at least to a **very** close approximation. That equality of the impedances between the two signal lines and ground is a necessary condition for a balanced interface to provide the noise rejection it is known for. It is also frequently the case that those signal lines carry a pair of signals that are of equal amplitude but opposite polarity, which can provide additional advantages such as improved signal-to-noise ratio, reduction of certain forms of distortion, and minimization or elimination of cable effects (if the criteria Ralph has described are met).

Components whose internal signal paths are balanced but which provide RCA connectors in addition to XLR connectors typically convert the unbalanced signal provided to the RCA connector or received from the RCA connector to or from a balanced pair of signals that is processed internally, with the conversion often being accomplished via either an active stage or a transformer. Or in some cases the RCA connector is simply connected to one of the two signals in the balanced signal pair, with the ground shell of the RCA connector being connected to circuit ground.

An interface which conveys a single signal and a ground connection is not balanced, both by definition and as a practical matter.

Regards,
-- Al



Shadorne.....thanks, but I sent the mid and trweeter drivers to Vandersteen who tested and deemed them fine.
The only reason James Cannon designed the XLR is for very long cable runs beyond 25 feet. A very well designed solid state preamp is quiet as a tomb and its redundant to use a 1 meter pair of XLR's since there is no noise to deal with. To create this myth that XLR cables have an effect on the quality and quantity of the music signal is outright fraud. The quality is in the recording itself whether its vinyl or CD and has nothing to do with the wire or the connector. If its a very bad recording its going to sound like crap regardless what cable your using, XLR or RCA. Now if you have a poorly designed preamp with a high level of cross talk and noise than the XLR will help to flush out the noise at the output. Its just wire with a good ground, its not a "mini preamp, a "processor", or a buffer like many
in the high end retail continue to perpetuate to make more money. David Belles who makes the finest solid state and tube preamps in the country in their price range, whose always off the radar, could care less about XLR's with his top preamps, soild state or tube. His pieces are dead quiet, all single ended, and when you listen to his model's, "balanced" cables will be the last thing on your mind.