Balanced cables

Just wanted to reiterate that if designer lays out his signal path to be more direct to the XLR and the gain is set higher to that output it will always sound better which is the intention, if the opposite is done to the RCA out, it will always sound better as well. 

+1 audiozen! Thank you for your cogent explanation and debunking of the "superiority" myth of XLR (Cannon) connectors!

Aw geez, once again folks here set up straw-men solely for the purpose of setting themselves up so they can nobly slay them before the spectating masses and then take a bow for imaginary accolades of heroic wisdom. Or put more simply, for crying out loud, gimme a break!  Nobody in this thread espoused the view that XLR's are inherently better than RCA's. Anyone who has read the leading audio mags knows that most of the better reviewers only have RCA IC's in their personal collections and if XLR's are the only option on a piece of gear, they borrow some from the manufacturer of the particular piece under review. But, when a component is designed for XLR's only, there is no choice. When a component offers both, setting aside the difference in gain, they sometimes sound different and sometimes they don't. Sometimes one sounds better than the other, sometimes they just sound different. This exact question posed by Stingreen, btw, has been covered here before. The responses are quite predictable. There is the camp that says no, all balanced cables competently made sound the same. There is the "all recording studios use Mogami/Belden and that is all you need" camp. And then there are the rest of us who say, "it all depends". Some of the most widely respected amps ever built don't offer true balanced inputs. Take Lamm gear for instance. There are XLR's on the back of Lamm amps but Vladmir Lamm is very open that they are "psuedo balanced". 

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.

Al addressed this correctly. I do have the feeling though that you did not read my post carefully. XLR connections were in wide use in the 1950s- my Ampex 351-2 tape machine, built in 1957, uses XLRs exclusively.

They were used by the recording and broadcast industries beginning in the 1950s, and their introduction to high end audio was made by me in the late 1980s (we introduced the first balanced line product for high end audio in 1987).

The reason XLRs are used for balanced operation is that the relationship of both the non-inverted and inverted signals with respect to ground is identical. This is important for a proper balanced connection and is something an RCA connector simply can't do.

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.

This paragraph is full of outright falsehoods so I will attempt to set the record straight.

The noise of the preamp is a different thing from the noise that can enter a cable. It does not matter if the cable is 6" or 60 meters. Balanced operation still has a noise advantage with respect to the cable, and the additional advantage of being able to eliminate cable artifact. If you had to pay big dollars for a single-ended cable because that was the one that sounded right, that's the kind of artifact I'm talking about!

Now balanced operation within something like a preamp can also have lower noise but for entirely different reasons. For example, we use differential amplifiers in our preamps; for a given stage of gain, a differential amp can have 6db less noise than its single-ended counterpart. 

Differential amplifiers are in common use in many solid state power amps and many opamps. They are used because they offer lower noise and also greater power supply noise rejection. They can be executed in tubes as well (the first production opamps were made in the 1950s by George Philbrick and were all-tube).

The bottom line is balanced operation is used to reduce or eliminate the sound an interconnect cable might impose in the system, and also to reduce or eliminate noise that might be impinged on the cable by power cords, magnetic fields and the like- these are things single-ended cables cannot do. This is why all recordings since the 1950s employ balanced line connections- its not just so that the cables can be run a long ways, but if you sit and think about it, the fact that the technology prevents the cable from modifying the signal does also imply you can run the cable much longer distances without troubles.  This can be quite advantageous in the home; I keep my amps right by my speakers with short speaker runs, and run the interconnect cables about 30 feet to my preamp which is located at the spot in the room with the least bass (room nadir). In this way I get considerably more definition and less coloration.

Again, you'd think that audiophiles would be all over that!

I knew Robert Fulton as he lived here in town. He was the guy that founded the high end audio cable industry. Back in the late 1970s he had a high end RCA cable, and his Fulton Brown and Fulton Gold speaker cables.

If you run RCAs, the cables to make the connections are the hidden cost of any preamp. If you run balanced, and the equipment supports the balanced standard, the cables are cheap but the sound is better than the best RCAs.

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.

You are correct. There are several ways to do balanced operation with tubes. If you want to support the balanced standard though, your options become limited because of the low input impedances the standard requires you to be able to drive, and also there is that issue with ignoring ground as I stated in my first post.

In the old days of tubes, an output transformer was employed. That is how my Ampex recorders (which are single-ended internally) drive balanced lines. When transistors came along, and in particular solid state opamps, it became possible to direct-couple the output. But even with solid state, transformers are still in common use even today.

We developed a third means, which is a direct coupled balanced vacuum tube output, for which we also developed a patent. I'm pretty sure ARC didn't have any interest in infringing the patent, using output transformers or a solid state output, so they used the only means left to them, which was to not support the balanced standard. They knew they had to do something because balanced operation offers too many advantages to ignore!

As a result, you can easily hear differences in balanced cables while using their equipment. This is entirely because the balanced standards are not being observed.

Just wanted to reiterate that if designer lays out his signal path to be more direct to the XLR and the gain is set higher to that output it will always sound better which is the intention, if the opposite is done to the RCA out, it will always sound better as well.

This statement is false.

Balanced and single-ended (RCA) operations are inherently incompatible. So if RCAs are used its not balanced, and if the XLR outputs are used (and the preamp is properly balanced) then the use of the RCA connections will result in a buzz.

IOW its one or the other and never both, unless additional active circuitry is used.

The gain has nothing to do with it whatsoever. That is saying that to make something sound better, you just make it louder.

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.

You are correct. There are several ways to do balanced operation with tubes. If you want to support the balanced standard though, your options become limited because of the low input impedances the standard requires you to be able to drive, and also there is that issue with ignoring ground as I stated in my first post.

In the old days of tubes, an output transformer was employed. That is how my Ampex recorders (which are single-ended internally) drive balanced lines. When transistors came along, and in particular solid state opamps, it became possible to direct-couple the output. But even with solid state, transformers are still in common use even today.

We developed a third means, which is a direct coupled balanced vacuum tube output, for which we also developed a patent. I'm pretty sure ARC didn't have any interest in infringing the patent, using output transformers or a solid state output, so they used the only means left to them, which was to not support the balanced standard. They knew they had to do something because balanced operation offers too many advantages to ignore!

As a result, you can easily hear differences in balanced cables while using their equipment. This is entirely because the balanced standards are not being observed.

So if I understand you correctly, unlike Vladmir Lamm's open admission to having psuedo-balanced XLR inputs on his amps, ARC's Ref Series amps, including my Ref 150se is truly balanced, but deviates from the convention most likely for the reasons you stated. I will leave it for another day and discussion as to whether you are correct that as long as the convention for true balanced is observed, all functioning XLR IC's will sound identical. I just know that with my Ref 6 preamp and Ref 150se amp, the choice of XLR makes a profound difference-I tried Mogami Gold, a custom-made Chris Sommovigo AirWave, a Morrow MA-6, a Harmonic Tech, and then Cardas Clear Beyond and each was markedly different. Only the Cardas gave me repeated goose bumps and chills down my neck and only the Cardas made my speakers disappear in my room. I am not touting Cardas as best, only that Cardas was the best I tried in MY system. 

Its probably not the amp that is causing you to hear the cables so much as the preamp. But there is a recent period of ARC amps that had me scratching my head. I'm not sure which models they are. They were out when Kalvin Dahl (with whom I went to school) was still at ARC (about 2-3 years ago). Apparently the amp has a very low CMRR (Common Mode Rejection Ratio) so it only has balanced inputs. Apparently also if you try to run it single-ended the power goes down and the distortion goes up.

I can't think of a good reason for a low CMRR in a differential amplifier (which is what these amps use). You wind up leaving performance on the table (I've been designing differential circuits since the mid 1980s).

If that kind of amp is used with a preamp of fairly high output impedance as per any of the ARC Ref series, the result will be that cable differences will be heard.

That last bit is the part I don't get- why defeat the purpose of balanced line? At that point you might as well run single-ended, as the ability to run long cables is lost as well.

It is things like this which is (IMO) why the single-ended/balanced debate continues! Think about this for a moment- from whom do you most often hear that saw that 'cables don't make a difference'? Usually its someone with an audio engineering background. Well, most of those people work in pro audio, where balanced lines are used, the balanced standard is observed and cables thus really don't make a difference. But in high end audio, for some reason (my guess is the difficulty) the balanced standards have been largely ignored, so this conversation continues...

Atmasphere 2-28-2018
Its probably not the amp that is causing you to hear the cables so much as the preamp. But there is a recent period of ARC amps that had me scratching my head. I’m not sure which models they are. They were out when Kalvin Dahl (with whom I went to school) was still at ARC (about 2-3 years ago). Apparently the amp has a very low CMRR (Common Mode Rejection Ratio) so it only has balanced inputs. Apparently also if you try to run it single-ended the power goes down and the distortion goes up.

I can’t think of a good reason for a low CMRR in a differential amplifier (which is what these amps use). You wind up leaving performance on the table (I’ve been designing differential circuits since the mid 1980s).

Ralph, I’ve never been able to find a schematic for any of ARC’s amps which only provide balanced inputs, such as the recent Reference series amps, but I’ve had the suspicion that instead of using differential stages they basically have a separate signal path through the amp (up to the output transformer primary) for each of the two signals in the balanced signal pair they receive for each channel. That would be consistent with a very dramatic reduction of power capability as well as an increase in distortion if the amp were to be provided with unbalanced inputs via RCA-to-XLR adapters or adapter cables, as was found to be the case with the Ref 150 used by the OP in this thread we had participated in some time ago. I believe it would also be consistent with low CMRR, due to the gain and other characteristics of the two paths not matching precisely.

I have no idea why they might have chosen that kind of approach, and I can’t say for sure that they did, but if I am correct in suspecting that they did so it would seem to explain some or all of the things you mentioned about their amps that you referred to above.

Best regards,
-- Al

It depends on who you believe

but I’ve had the suspicion that instead of using differential stages they basically have a separate signal path through the amp (up to the output transformer primary) for each of the two signals in the balanced signal pair they receive for each channel. That would be consistent with a very dramatic reduction of power capability as well as an increase in distortion if the amp were to be provided with unbalanced inputs via RCA-to-XLR adapters or adapter cables, as was found to be the case with the Ref 150 used by the OP in this thread we had participated in some time ago. I believe it would also be consistent with low CMRR, due to the gain and other characteristics of the two paths not matching precisely.

Al, that makes a lot of sense to me, but both Warren Gehl (of ARC) and Kalvin told me that the amp employed a differential amplifier at its input. But they may have been reading off of the same cue sheet, which may not have been accurate. Although I've known both of them for 40 years, on this point I'm more willing to believe your theory as it is consistent with the amp's behavior. I never had the heart to to tell them that if what they said was true that a lot of performance was being left on the table. But who knows- maybe that will be part of the next iteration.

At any rate, that aspect of the amp's performance is well-known and acknowledged by ARC. So in the case of a balanced interconnect, if noise were able to impinge the cable, the amp would not be very good at rejecting it (in the old days this was often handled by an input transformer, which is usually very good at CMRR). So this would seem to make the characteristics of the cable more audible. For such an amplifier, I would recommend a cable that is double shielded.

Al, that makes a lot of sense to me, but both Warren Gehl (of ARC) and Kalvin told me that the amp employed a differential amplifier at its input. But they may have been reading off of the same cue sheet, which may not have been accurate. Although I've known both of them for 40 years, on this point I'm more willing to believe your theory as it is consistent with the amp's behavior. I never had the heart to to tell them that if what they said was true that a lot of performance was being left on the table. But who knows- maybe that will be part of the next iteration.

At any rate, that aspect of the amp's performance is well-known and acknowledged by ARC. So in the case of a balanced interconnect, if noise were able to impinge the cable, the amp would not be very good at rejecting it (in the old days this was often handled by an input transformer, which is usually very good at CMRR). So this would seem to make the characteristics of the cable more audible. For such an amplifier, I would recommend a cable that is double shielded.

At the risk of coming across as overly defensive (I own and love ARC gear), this sounds just a bit too conjectural/speculative. Warren Gehl to my knowledge does some very limited design work for ARC and is key in QC by reportedly listening to every piece of gear hooked up to his reference system of a Ref 6 and Ref 150se and some old, large Magnepans before the piece leaves the factory. It was, however, Ward Fiebiger who took over the reigns from Bill Johnson in the actual engineering/circuit layouts of ARC's top-level gear including the Ref series of preamps and amps. Now does that make a difference? Probably not. Surely Warren knows enough to answer the question being posed here. I actually tried to ask ARC the very same question, more or less. Guess what they said in response to my email? That I should contact my dealer! Very nice, huh? 

FWIW, I'm looking at my manual to my Ref 150 SE and it does not include a schematic and instead only has some specs, including that the output polarity is non-inverting with "Balanced input pin 2+ (IEC-268)"
Also interesting to me is this verbiage;
"IMPORTANT
Use the best available speaker wires and interconnects. Audio Research cannot emphasize this enough. As better components and systems are developed, it becomes increasingly important to avoid the limitations of inferior system interconnections"

Warren Gehl to my knowledge does some very limited design work for ARC and is key in QC by reportedly listening to every piece of gear hooked up to his reference system of a Ref 6 and Ref 150se and some old, large Magnepans before the piece leaves the factory. It was, however, Ward Fiebiger who took over the reigns from Bill Johnson in the actual engineering/circuit layouts of ARC's top-level gear including the Ref series of preamps and amps. Now does that make a difference? Probably not. Surely Warren knows enough to answer the question being posed here.

Warren has made a lot of contributions to the sound of ARC and little of it has been to circuitry- mostly vibration control, tube choice and similar. Bill hired him for his ears as he was/is very astute.

Ward (RIP) may have been influenced by the Italians who have since learned to let the company do what it does best. I'm not sure where your amp sits in this since it is still current.

I have seen some pretty expensive cables over at ARC (they are a 1/2 hour drive from here) so I've had pretty good reason to suspect that they didn't support the balanced standard (else you wouldn't need the pricey cables). Here is a nice bit about how balanced line works, from the Rane (a popular pro audio manufacturer) website:

http://www.rane.com/note110.html

@stringreen ,

Are you listening to lps, cds or both when you experience the metallic sound? If it's only on lps, (if you're still running the Classic platter), I'd suggest you try a nice TT mat...Funk Firm 5mm.

Good luck.

@fsonicsmith
Good points. Though, I’d assume most reviewers don’t have XLR on hand because only a small subset of gear actually *requires* it.

In the case of components which offer both XLR and RCA inputs and/or outputs, it’s probably worthwhile to understand the circuit topology. I don’t know what "pseudo balanced" means. But in many cases (such as in my EAR Yoshino gear), the balanced connectors are offered as a presumed convenience only. For example, my EAR 890 amplifier has balanced and unbalanced inputs selected by a switch. And when I switch to the RCA inputs, then the input transformers are bypassed. Transformers are probably the best way to convert balanced to unbalanced or vice versa, but they have a sound. So now if I prefer transparency, then I should use the unbalanced inputs. But if I prefer the additional transformer coloration, then I could use the XLR. One is not definitively "better", and the only thing to do is try it both ways.

One possible benefit in general of balanced is the elimination of any potential ground loops.

Just because you have XLR inputs and outputs on a piece of equipment does not mean you are running in true balance. Check with the maker of the equipment to see if they are true balance from input to output. If they are then i feel the XLR balanced cables will make a difference. If not do not waste your money.

@68pete

That was exactly my point. Also depends on the source. If a phono, which in MOST cases run single ended in, then I don’t see a reason to favor converting back and forth from single ended to balanced downstream in the chain vs just staying single ended all the way.... assuming you don’t have a mixture of true balanced devices and single ended devices in the chain - which itself is a little weird.

@ audiozen you said,

"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."

Very interesting. Not meaning to railroad the discussion but are you saying TheCableCompany can help match the best IC's for your system based on mathematical value designs each company has for their components? If it's that simple why don't companies list those values in the specs for their products? I've got the Primare A32 power amp and Pre32 preamp (both fully balanced) and am presently using Violectrics XLR IC's (a brand TheCableCompany doesn't even carry) and I love the sound. I'd be curious to see if the mathematical values of these products truly compliment each other. I know it doesn't "really matter" as long as I like what I'm hearing...just curious.

Am I correct that if an interconnect length is 50’ it is uncontroversial that XLR is the way to go?

Slaw....I hear the "metallic" sound from all sources.   I tried many mats and insist my bare Classic platter is best for me.

When running mic cables in my distant past, of 100m or more balanced was the way. And transformer balanced , too.
From a low impedance (100 ohms ) would keep the system quiet even after crossing and running alongside hundreds
of power cables.
IC balancing was cheaper but not as effective in industrial use.

In my experience moving to balanced from single ended prodiced a slight increase in articulation, most noticeably in the bass.

Through my many years being in the audio business, and listening to an even greater extent I always return to unbalanced interconnect cables for betters sound. Fortunately my Audio Research amplifiers and line stages have provisions for both so it makes a good test. I've done nearly all of my A/B testing using the same brand XLR vs. unbalnaced (RCA) connectors.

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."

I didn't want to say anything at the time, but this is so wrong in so many ways. TheCableCo. is not in Ohio, not that it matters much, but this falsehood sets the tone for what follows. I can only hazard a guess that the "values" he mentions pertains to output impedance and input impedance but those "values" have nothing to do with matching cables to components. People say all kinds of weird things on the internet and it is best to just smile and ignore. I have just broken from that wisdom. 

From a high end PRO perspective, there is just as much difference between high end and low end XLR cables as there is in high end and low end unbalanced RCA cables.  The cheapest XLR cables are absolute crap and roll off the top end and make the low end muddy, midrange cloudy- just like unbalanced cable. 

The reason most pros use XLR is noise floor- having a shield that encloses the positive and negative audio cable inside to protect it from outside noise.  In high density cities like New York, LA, Dallas, etc RF is everywhere and can make noise that shows up in the audio of an unbalanced system.  If a RF tower is near you that can sometimes create issues.  

Having a complete system balanced is key in high pressure environments, like a recording studio.  All you need is someone drive by with a big output RF device and your recording would be completely ruined.  This used to be common when CB radios where popular.    

Some like unbalanced better because HOW many designers balance their audio devices inputs and outputs can affect the sound quality of an audio device or signal chain of multiple audio devices.  

Some balanced cable is a spiral shield, and not 100% coverage of the audio cables within.  100% braided shield is the better method for RF protection but it can make the cable less flexible.

Electronically balanced input/output stages vary in sound quality depending on design.  THAT corp designs a great electronic balanced stage called OUTSMARTS we use an output stage of a mic preamp.  We still use a Jensen transformer on the mic input.   Transformer vs electronically balanced outputs do sound quite different.

If you run balanced cable and balanced devices and then insert one unbalanced device in the middle, the system is unbalanced at that point and any noise present is now in the audio path regardless of balancing later.  The shield just protects the audio cables within.  Remove the shield or reduce its coverage and the noise is back.  
       
High capacitance cable can be a problem, especially when used with a microphone.  The top end is affected by this build up of capacitance over its length.  Make sure you read the cable specs and avoid this high capacitance cable.

XLR cables in balanced rigs can be run long lengths noise free.  That does not mean they sound good over long runs.  There is HF loss or at least changes in HF audible with longer cable runs.   But in some cases like broadcast, it does not matter so much, the noise avoidance is the goal. 

Brad

  transaudio

The reason most pros use XLR is noise floor- having a shield that encloses the positive and negative audio cable inside to protect it from outside noise. 

No, pros use balanced XLR cables because of their Common Mode Rejection Ratio - the very nature of a balanced circuit. They don't require shielding to achieve low noise. Unbalanced lines, however, often benefit from such shielding.

 

They don't require shielding to achieve low noise.

This is true- I've used balanced Kimber which has no shielding at all and over 30 feet, not hum/buzz whatsoever.

I'd like to thank @atmasphere and @almarg for participating whenever discussions involve balanced cables / components.

I've noticed a few assumptions that lead to confusion surrounding balanced cables / components. Here's how I generally cut to the chase:

1. XLR terminations on a cable do not (necessarily) mean the cable is of a balanced design. Sometimes the designers design to the "spec", sometimes they get close, sometimes they don't care.
   
2. XLR connectors on a component do not (necessarily) mean the component is of a balanced design. Sometimes the designers design to the "spec", sometimes they get close, sometimes they don't care.
   
3. When designers design to the balanced "spec", things play together with less variance due to the component interactions through the connections (and have less impact through noise that may be injected into the system). Everything else requires much more "trial and error" with regard component matching.

In summary, the value of balanced components using balanced cables (generally leveraging XLR terminations / connectors) designed to the the balanced "spec" are 2 fold:

1. What @cleeds states  - Common Mode Rejection Ratio. CMRR (in overly-simplifed terms) mean when noise enters the signal path, it affects the (+) and (-) legs identically. When the (-) signal is inverted and summed with the (+) signal, that noise magically cancels itself out.
   
2. The input (and output) impedance of the components are sufficiently low (or high, respectively) for generally optimal transfer of signal.
   

@2channel,
+1

Bob

As was mentioned above, the output of a "balanced circuit", if truly balanced, will almost always double the output voltage of that device. Just because a component has XLR connectors, doesn't mean the circuit is fully balanced.  I don't care when the term "balanced" was introduced, the outcome is the same. Balanced cables are a huge asset when running longer lengths, or when cris-crossing line voltage wiring.  You have two separate signal wires, both shielded by the woven mesh.  This eliminates possible 60hz hum, or IR interference, that can and sometimes will present itself, when using SE cables.  I wish my Rhea had balanced phono inputs, but as someone once said, " you can wish in one hand a shat in the other and see which one fills up first."  As far as SE phono interconnects, I found that when making my own, using 2 conductor with a messed shield, leaving the mesh out of the circuit on one end, will greatly improve the sound, by keeping the signal wires shielded from any interference that may be picked up from induction.  In the long run, no pun intended, whatever works best for you, is what you should use.  The original question was about different brands, not if balanced is better.  For me and my application, balanced works best for me.

Do balanced interconnects, perhaps because of common mode noise rejection, tend to suppress even order harmonics?

Could this be one reason some people feel single-ended connections sound more natural and musical than balanced connections?

When I started getting serious about this hobby in the 1980s, one didn't hear too much about cables. (At least I didn't; but then I wasn't looking.)
When I returned to the hobby in 2015 I ordered a NAD dedicated CD player. The dealer sold me a pair of AudioQuest Alpha Snake ICs for $24 to go with it. While I was waiting for the NAD to be delivered I put the Alpha Snakes on an old ADC CDP that it was replacing. I immediately had to turn the volume down on the amp. So I was convinced that the cheap ICs that came with the players were garbage. I was not convinced, however, that spending more than $25 was prudent. 

A few years later and my system became much more capable of revealing detail. I bought a pair of WireWorld Oasis 7s for about $100. They made an improvement in soundstage and carity from my Oppo BDP-95 through a Rotel Rx-1052 and Canton Ergos that I thought was not just my imagination. Later I replaced the Oasis 7s with inexpensive Gotham PUR XLRs. (now through a Primare I32) This was an improvement that I absolutely and immediately knew was not my imagination. Next I got some Zu Mission XLRs that I believe listed for about $215. I'm not sure I hear any improvement over the $35 Gothams, but this does not surprise me. I had thought that the nature of balanced circuits and cables is much more immune to cable differences than RCAs. Since I got the Zus for only $45, it was not an expensive experiment. It seems that some of the followers of this thread who are far more knowledgeable than I have confirmed my theory. I am insecure enough to take comfort in that.

handymann

Balanced cables are a huge asset ... You have two separate signal wires, both shielded by the woven mesh. This eliminates possible 60hz hum, or IR interference, that can and sometimes will present itself, when using SE cables.

Again, this is mistaken. The ability of a balanced cable to reject interference isn't because of shielding, which many balanced cables completely lack. Rather, it is the nature of the balanced connection itself and the common-mode rejection ratio that results. Shielding can very much be a benefit with single-ended cables, however.

ronres

Do balanced interconnects, perhaps because of common mode noise rejection, tend to suppress even order harmonics?

I don't think so, or even understand how that could be possible.

At least for me, Atmasphere, and Almarg have given all the information needed regarding balanced interconnects.
I think nrenter summed it up nicely, too.
So, would I buy an expensive XLR cable?
Probably not.
B

@elizabeth,
Though I respect Kimber, I would have a hard time justifying $3K for interconnects. 
Do you notice such a significant difference in sound reproduction?
And, I only say this as a question.
Bob

@stringreen 

Back to the intent of your post...

What are you using for power distribution? I’d maybe try an Ayre 5-Lxe in front of your source components. Yes, “Ayre-conditioning” is already part of each component of your Ayre stack, but I recall the late, great Charley Hansen touting the benefits of double-conditioning on another forum. I believe he claimed the transformation was so significant that the pairing of a 5-Lxe and an AX-7e was part of his personal reference system (before the R series was released). It’s why I use that factory-modified combo with my Vandersteen Quatro CTs. 

I was wondering if/when this was going to happen? Was this wrong?

Just last year I bought a $3,100 XLR cable.
Seven meter Kimber KS1116

For that money you could get a preamp with high output (around 18 volts vs the regular 2 volts). A better higher output component will be unaffected by either the type of XLR cable and/or length. Usually it is interconnect capacitance that affects weak low cost consumer (low-fi) gear resulting in less dynamics. RCA is terrible but of course no serious audiophile would ever use RCA. 

Again it is sad to see folks misplacing blame on interconnects when it is the components that are at fault for any audible degradation.

@elizabeth, again.
Given the posts by Almarg and Atmasphere, do you consider your equipment to be fully balanced?
B

true balanced mainly seem to belong to the marketing gimmicks...

@elizabeth ,
I disagree. From what Ralph/atmasphere has written, it is clear that a true balanced circuit-while not saying it sounds better, provides the means to transfer a signal with far less chance of being affected by noise or being affected by cable design.
I think this is why you are hearing differences between different cables. 

spending twice as much to build the same end result might be OK.

But, you ended up spending a lot of money buying cables.

And I see nothing which would make such designs a requirement for
better sound.

Again, I disagree. Designs like fully balanced, zero feedback and OTL, definitely do make a positive difference.
Though I have no doubt that you have an excellent stereo system, and a sensitive ear, I only wish we could compare our two systems. I think it would be enlightening for both of us.
Bob

Is it true that the XLR cables carry both an inverted and non-inverted signal, and that the inverted signal is re-inverted and additive, resulting in the 6 dB gain and good for long runs?  Any externally induced noise in the wires is then out of phase (because of the last inversion) and self canceling - also good for long runs.  I thought those were the technical reasons for XLR.  How does the grounding scheme affect from a technical and musical standpoint?

Wlutke, that’s sort of correct, but I would put it somewhat differently. In a good design an XLR cable will be provided with inverted and non-inverted signals, as you indicated, and those signals will be received a differential receiver circuit which responds to the instantaneous **difference** between the voltages of the two signals. Since the two signal wires in a properly designed XLR cable are twisted together, and the circuits they are connected to cause (or at least should cause) them to have equal impedances relative to ground, induced noise will be essentially identical in the two runs, and therefore there will be little or no difference between them, in terms of noise, for the differential receiver circuit to respond to.

In many designs it is also the case that the amplitude of each of the two signals in a balanced interconnection has the same amplitude as the single signal in an unbalanced RCA interconnection. In such a case the instantaneous difference in the amplitude received by a differential receiver circuit via an XLR connection will be twice the amplitude that would be received from a single-ended signal, resulting in the 6 dB difference in overall system gain that you referred to (assuming everything else is equal, including the setting of the volume control).

There are some lesser designs, however, which provide XLR connectors simply as a convenience feature, and provide that connector with just a single-ended signal and a ground. Also, in cases where a differential pair of signals is provided and received, the quality of the differential driver and receiver circuits may be less than optimal in some cases, and an RCA connection might provide superior results in those cases.

Regarding the grounding scheme, as indicated in the Rane application note which Atmasphere referred to in one of his posts dated 3-1-2018, ideally the shield of an XLR cable should be connected via pin 1 of the connector at each end to the chassis of the connected component. However for whatever reason many designs connect the shield via pin 1 to signal/circuit ground instead, which depending on other aspects of the design can result in some fraction of the signal current being conducted via the shield, in turn increasing sensitivity to cable differences as Ralph explained.

Regards,
-- Al

Thanks Al,
It really helps (me at least) to have all that info in one coherent explanation.  

HELP - pls:
I have a preamp w/XLR and RCA outputs, new tube amps in transit that have only RCA inputs and existing balanced (Transparent w/box) ICs previously used w/ARC 210 tube amps.  I have Cardas XLR>RCA adapters on the way too. The distance from preamp > amp is about 1 meter)
I've read all of this thread (lots over my head) but am left with the question of whether using the adapters (to avoid more cable cost) is liable to hurt/help/or be null.  Please advise/inform me.
Thanks

You have to tell us what brand the amp is.
B