The AudioQuest XLR Chronicles | REVIEW

xlr interconnect

This review of several models of AudioQuest XLR interconnects has taken a long time–well over a year, in fact. At first I wanted to discuss XLR interconnects on a bigger scale, including other brands such as the Furutech NCF XLRs interconnects I reviewed not too long ago. (I had those interconnects a long time as well before completing that review.) Over time, things got complicated.

First of all, it didn’t take long to find myself waist-deep in the whole XLR vs. RCA debate. Second, I had issues with getting review amplifiers that used XLR for inputs. Finally, I realized how difficult it is to perform quality A/B comparisons between interconnects when you need to ensure that all the cables have been properly broken in, which obviously takes time. But let’s start from the beginning.

Words and Photos by Marc Phillips

The first time I used XLR interconnect cables, the dang things got stuck in the jacks and I needed a technician to extract them. Not an auspicious beginning.

Now, in 2023, I’m genuinely concerned about the future of the XLR interconnect. For years I was told XLR connectors were far superior to RCA connectors, with most of these advocates stressing the importance of longer cable runs without signal loss, which is certainly ideal when you want to build a system where the speakers aren’t flanking your equipment rack and creating a whole new set of problems. (I’ve always felt that as long as the front baffles are closer to the listening spot than the rack, I’m good.)

After mentioning that very attractive advantage, some XLR fans will mention “better sound” compared to RCAs. But over the last few years I’ve met a few people who are not fans of the XLR interconnect and totally prefer RCAs (or in digital circles, coax or S/PDIF or optical).

I’ll give you the first example. When we started importing and distributing Pureaudio amplification from New Zealand back in 2012, I noticed right away that all the input and output jacks were RCA only. The dealers and prospective customers noticed, too. “A $10,000 preamp and a $16,000 pair of monoblock power amps and there are no provisions for XLRs anywhere?” When I talked Gary Morrison, the designer, he explained that his amplification was purist–short signal paths, as few parts as possible, quality over quantity.

Gary explained, “Having XLR connectivity places the burden of the technology on the amps, not the cables.” If you’re going for minimalism, an XLR interconnect is not the best solution. Besides, Gary told me that he tried XLRs in his designs and they simply didn’t sound as good as RCAs. That was the first time I heard something negative about XLRs, but it wasn’t the last.

While I was in Aalborg touring the Audio Group Denmark factory, I asked Lars Kristensen about his views on XLR. I’d noticed, of course, that Ansuz seemed to make every type of cable under the sun–except for you-know-what. Lars wrinkled his nose. “We don’t like XLR,” was his simple yet firm reply.

But wait a minute. Now that I’m on the XLR train, everyone is going back to RCA? I had one more engineer tell me that RCA was crap, but it was the best crap we currently have. But is there anything inherently wrong with XLR interconnects?

xlr interconnect

The Problem with XLR Interconnect Cables

I asked Bill Low of AudioQuest straight out–which is better, an XLR interconnect or an RCA? Here was his reply:

“It’s dead wrong for anyone to state that single-ended or balanced is always better — stupidly wrong — as it is to unequivocally state that Coax is better or worse than AES/EBU, or even than Toslink. They are all a matter of context. It is reasonable and necessary for a designer to have strong opinions about the path they chose.
“It is business-reasonable, but very unfortunate that some manufactures have an XLRs-is-us attitude when some of their gear is unequivocally superior when used single ended. The reverse is less of a problem, but also just as stupid some of the time. Context is everything.
“From a company like AQ, for which balanced cables have 3 dedicated conductors and single-ended cables have 2 dedicated not-the-shield conductors — single-ended and balanced cables are 100% equal at doing their job — but context will pretty much always make one or the other superior.
“That XLRs usually have a lock so they can’t fall out is trivial in our world — but at least XLR pin size standards are better adhered to than RCA plug and jack dimensions — but it’s a bit easier to make custom RCA plugs with an ideal connection to the cable than is true for an XLR. The RCA plug is everyone’s favorite whipping boy — but it does not have to be an inferior connector.”
Garth Powell, Senior Director of Engineering for AudioQuest, who was extremely helpful when it came to teaching more about grounding and noise dissipation technologies a couple of years ago, had this to add:
“The issue with XLR versus RCA (single-ended) is that the conclusions as to which is superior have almost solely to do with the circuits involved (assuming everything that can be done where the interconnect cable topology-technology is concerned have been achieved). The advantage of a pure differential circuit is the common-mode noise rejection within the bandwidth of the circuit. This is quite useful and audible in its ability to greatly reduce noise masking effects from stray magnetic fields (such as the AC portion of a component power supply).
“Unfortunately, induced RF noise is not affected (noise-cancelled) as radio frequencies are typically well above the circuit’s closed or open-loop bandwidth. This gives single-ended (with a remote power supply) a slight advantage, but the headroom of a well-designed differential circuit has its charms as well. It really depends on the circuit design and its designer’s talent and preferences.
“What I find unfortunate, is that this debate is almost always an unfair one when it comes to comparing the two connection options within one component. In truth, a true differential design will be somewhat compromised when strapped as a single-ended connection. Conversely, a single-ended circuit that uses a transformer or phase-splitter variant to achieve its balanced signal connection is likely to yield the best sonic results as RCA (single-ended). It’s not a fair comparison. Ideally components would be offered one or the other (two options per model), but that’s a marketing, cost, and logistical problem.”

My particular problem with XLR over the last few years has been availability, as in “I don’t have any XLR interconnects to try with this amplifier.” This first occurred a few years ago, when I reviewed the fabulous McIntosh MC2152 70th Anniversary power amplifier. This was probably the nicest amp I’d reviewed at that point, and it accepted both RCA and XLR. In my mind, a little voice said that I shouldn’t review the Mac with just RCA cables running to the pre. I should try the XLR outputs if I wanted to be serious and hear this amplifier at its best. Plus, an extra-long length of XLR interconnects would help me keep this big and heavy amplifier off my rack.

As I stood and pondered this dilemma, my significant other surreptitiously texted her younger sister and before I knew it I had a 6m pair of Cardas Audio Beyond Clear interconnects in my system. While reviewing the Mac, I did find that the Beyond Clears sounded much better than whatever RCA interconnects I’d been using. But was that the connectors, or the Clear Beyond itself?

xlr interconnect

Would You Say I Had a Plethora of XLR Interconnect Cables?

Once I appreciated the obvious benefits of the Cardas Audio Clear Beyond XLR interconnect and put it into print in the McIntosh review, the heavens parted and a whole slew of XLRs landed on my front porch.

First up was AudioQuest. I received several pairs of XLR interconnect cables from up and down the line–Red River, Yukon, Wind. Then I was sent the beautiful flagships from the flagship Mythical Creatures line, the Firebird and the Thunderbird.

Furutech then approached me with their new XLR interconnects that used their proprietary NCF material. I’m already a big fan of NCF, and I use several of these devices throughout my system. They wanted me to compare the NCF versions to the Furutech Lineflux RCA cables I already use.

That’s a lot of XLR interconnect cables, with prices that range from $595 to the close-to-five-figure range, depending upon length. For months now I’ve been wondering when I’d be able to sit down and try my hand at a few XLR/RCA comparisons. I wanted to get answers about the future of XLR. My only problem? None of the amps coming in for review used XLR! We’re talking Aavik from Audio Group Denmark, of course, but also Lab12 and Audio Note UK and a few others, including my reference Pureaudio amps. I have been playing with that older Ayre V-3 power amp and it has balanced and unbalanced outputs, but I still lacked a preamp with XLRs.

Fortunately, I had two impressive amps in for review that had full XLR capability, the Musical Fidelity M8PRE preamplifier ($4,999 USD) and the Burmester 101 integrated amplifier ($12,000). I was finally able to get this XLR ball rolling. I was also able to perform some early impressions when I reviewed the CEC TL-1 digital transport and DAC 5 DAC and used the AudioQuest Mythical Creatures XLRs to link the two components to the preamplifier.


Pardon Me, Where Do I Insert this XLR Interconnect?

That was one more problem to work out. I asked several of my peers another question: if you’re comparing a single XLR interconnect in your system, where will you put it so that the differences can be easily detected?

Bill Low has this to say about AudioQuest XLR interconnect cable placement within the system:

“It often makes a small difference in scale where in a particular system one makes a comparison, but anywhere will allow the same understanding and ranking.
“The difference might be more obvious in one place than another due to the idiosyncrasies of that particular output-to-input equipment pairing. As with single-ended vs. balanced interconnects generalizations are not useful, and are irrelevant. Far more important would be the character of the system, speakers and room — because they will have an effect on the tolerability of different distortions — because all too often cables are chosen for their voice and not for their lack of voice. The compatibility of errors is a crucial consideration elsewhere in a system, but has no place when evaluating cables or power products.”
Many told me to put it between the preamplifier and the source. I thought the answer would be between the power amplifier and the preamplifier for the simple reason that this was the connection closest to the wall. (This point would be moot, of course, with the Burmester integrated.) Apparently I was thinking about power cords, where that first cord that plugs into the wall makes the biggest difference. (I learned this in Aalborg after intense A/B comparisons.)

Again, Bill Low’s take on that:

“If by ‘first cord that plugs into the wall’ you mean the cable to a Niagara (for example), then well yes, because the entire system is affected by the one cable. Otherwise — AudioQuest certainly has an often-correct starting point as to which one AC cable might make the most difference — though as with my comments above, it’s irrelevant whether one location reveals 20% more or less difference than another location. The difference will be just as obvious in any location.
“But yeah, we like to load the dice if we can, and so the DAC is our preferred starting point. A DAC’s job is to convert signal-carrying impossibly high-frequency noise into an analog waveform. It’s simplistic, but that seems a workable explanation for why reducing RF interference with a DAC’s function is a bit more crucial, maybe even more so than the very difficult job a phono preamp has to do.
“Also, there is dramatically more gain in low-level components than in a power amp, reasonably making a power amp somewhat less sensitive to some issues — though compared to constant-current sources and preamp, amplifiers are extraordinarily more sensitive to unrestricted transients in the delivery of power to the amp’s power supply.
“As for where to compare interconnects — wherever one feels like and can reach the gear’s inputs and outputs. Hierarchy is a false errand — at least without awareness of some input or output eccentricity, though that is much more likely to be an issue negating treating a single-ended vs. balanced result as universal.”
Garth Powell had this to add:
“As a starting place I agree with your colleagues, but for this specific reason. Where noise dissipation and drainage of induced RF noise is concerned, the lower the signal level, the more the signal will suffer from noise masking. This effect is most dramatic going from a phono preamplifier to a line-stage preamplifier, but a DAC to a line-stage preamplifier is also valid as we are cascading gain as the signal move forward towards the power amplifier’s output stage.”

So I decided to focus on one link in my system–from my preamp to the Lab12 DAC1. I chose the Lab12 because it’s one of the finest DACs I’ve heard, and it sounds more like analog than almost any other digital I’ve heard, except for maybe the far more costly Aavik/Ansuz digital rig that just left my house.


Battle of the AudioQuest XLR Interconnects

If you really think I’m going to listen to all of these XLR interconnect cables and then I’m going to compare and rank them in order or preference, you haven’t been listening. Besides, this took a while to do. Cables need to break in. After all was said and done, I wish I’d contacted my buddy Alan Kafton, who makes The Cable Cooker. I like Alan a lot, and I’ll give him a plug because we’re good friends, but I’ve always thought “neat product, don’t need one.” Now I see you, Alan. I see you.

As I mentioned, this review evolved into a survey of all the AudioQuest XLR interconnect cables I’ve accrued during my time at Part-Time Audiophile. I’ll also mention that I’m grateful for Bill Low, Stephen Mejias and Garth Powell who were so patient and helpful when it came to affording me the time to find out “the truth” for myself.

For the record, these are the AudioQuest XLR interconnects I’ve tested over the last year (or is it closer to two by now?):


AudioQuest Mythical Creatures Firebird ($9,500/pr 1.5m) and Thunderbird ($4,700/pr 1.5m)

Both the AudioQuest Firebird and Thunderbird had plenty of time in the system when I reviewed the CEC TL-5 transport and DAC. I flipped over the sound of the CEC digital rig–I thought the sound quality was superb. How much of that was due to these Mythical Creatures XLR interconnect cables?

When I first received the Firebird and Thunderbird from AQ, I immediately received a note from Skip at Audio Thesis–the gentleman from Texas who arranged for the review of the Rosso & Fiorentino Pienza Mk. 2. Skip prefers the Mythical Creatures for the R&F and Norma Audio gear he imports from Italy. He kept sending me messages asking what I thought, implying that he was over the moon and he wanted to see if I concurred. After the CEC review, I’d say yes, I concur.

In this test rig with the Burmester 101 integrated and B18 loudspeakers and the Lab12 DAC1, the AudioQuest Firebird XLR interconnect cables had this almost regal air about them, as if this is as beautiful as the music gets and we should just listen and not ruin the moment with mere words. The quality I noted first was a delicacy in the system through the treble, with high frequencies spread out on a three-dimensional mapping system. This gave me the sense of reaching almost limited highs in the treble while streaming, and that unexpected sweetness we find way up there in the stratosphere.

Clarity? Transparency? That’s all I can think of at first, but as I fly through my music I keep hearing new little tidbits and I’m constantly wondering if this is a remaster or if that strange thing I just heard was always there, and it was.

But I’ll remember those extended highs the most. The crazy thing is this: both of the digital sources, the Lab12 DAC-1 and the Unison Research CDE CD player, have tube output stages. Perhaps that why I truly enjoy both–those tubes make the digital sound more like analog. But have a heard high frequency response this sweet, this smooth and this full of light–with valves? Well, I wasn’t surprised.

audioquest mythical creatures

The AudioQuest Firebird and Thunderbird XLR interconnect cables, as well as most of the Mythical Creatures line, are described on the AQ website as follows:

“AudioQuest’s 42-year history of designing and refining analog interconnects has been a long, steady climb up a mountain, the summit of which can never be reached…

“But with each step, we have arrived at cleaner, clearer, more naturally detailed and beautiful sound. For the most part, improvements in performance have been incremental — small steps, always in the right direction — but, just a few times along our 42-year path, new materials and/or technologies have brought so much improvement that it’s as though we took a chairlift to at least the next base station.”

Both of these XLR interconnects cables benefit from AudioQuest’s new ZERO-Tech technology, which minimizes the typical cable interaction between circuits with mismatched impedance between components and cables. We’re talking, of course, of distortion caused by impedance mismatches, something I’ve encountered in the past with phono preamplifiers and step-up transformers. If you can reduce noise and distortion from the signal path, that means you’ll hear the key concept in high-end audio of letting the music flow in a more unfettered manner.

Again, AudioQuest offers additional info on how the Firebird and Thunderbird XLR interconnects achieve this:

“The Mythical Creature Interconnects make the multiple discrete signal and ground-reference paths externally visible for the first time — but that is not new technology. It is because the more complicated and optimized implementation of ZERO-Tech would have made the cables stiff and unfriendly if all hidden in a single round jacket.”

AudioQuest has also employed their Dielectric Bias System (DBS) in these cables for even better results when it comes to isolating between “inverting and non-inverting positive signal constructions.” That, in a nutshell, is the remarkable innovation found in the Mythical Creatures line. You’ve probably seen DBS many times in the past–that’s the little battery modules attached to the cables. AudioQuest discovered that two DBS systems together yield better results, but the engineers took an additional step of housing both DBS systems into one enclosure for a more streamlined look.

These XLR interconnect cables also implement AQ’s Noise Dissipation technologies to reduce RF interference, which has become even more important in this age of digital technologies that require wireless operation. The Firebird and Thunderbird cables also feature a carbon and graphene mesh network and silver-plated shield drains. This is one of the main differences between the Firebird and the Thunderbird–the latter uses copper plating while the former uses silver, which also reflects the difference between the GroundGoody Jupiter and Saturn grounding wires I reviewed some time ago.

audioquest thunderbird

The sonic differences between the Thunderbird and the twice-as-expensive Firebird (as well as the Dragon, the top model in the Mythical Creatures line) are not huge, but they are noticeable–especially when you have a highly-resolving system that excels in inner detail.

Basically, both cables sound like nothing when added to the system. So while I was initially concerned that the Firebird and Thunderbird were pushing the performance envelope of the CEC and Burmester equipment, they were actually letting that gear be its natural self, so to speak. The result was something akin to all of the noise-reduction and grounding products I’ve recently discovered–more detail, crisper transients and even some noticeable improvements in frequency extension. The Firebird, predictably, got me closer to “no cable at all,” just the music as intended.

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AudioQuest Wind ($3,100/pr 1.5m)

Before the AudioQuest Thunderbird and Firebird XLR interconnect cables arrived, the Wind was my go-to for AQ XLR connection. Aside from the Mythical Creatures cables, the Wind was the only AQ interconnect I had with the DBS technology. I’ve been using them a lot over the last few years.

The Wind, along with the other AQ XLR interconnect cables I have on hand, all belong to the Rivers & Elements series. It uses AQ’s Solid Perfect-Surface Silver (PSS) conductors.

While the Thunderbird and Firebird were downright triumphant when it came to disappearing within my system, the Wind wasn’t far behind. (In fact, I’ll venture to say that the Wind and the Thunderbird were fairly close in this respect, but still distant from the Firebird.) I also found that the Wind could approach the quiet, revealing nature of the Mythical Creatures cables when used with other grounding and noise-reduction products–such as those GroundGoody grounding wires. The Firebird and the Thunderbird, however, easily accomplished those goals with little or no assistance.

audioquest yukon

AudioQuest Yukon ($680/pr 1.5m)

For another take on the AudioQuest Yukon XLR interconnects, you can check out Graig Neville’s review of them for PTA. (He still uses them as his reference XLR.) You’ll obviously notice a big price differential between the Yukons and the first three XLR interconnect cables–the Yukon does not use DBS, for instance, and the PSS conductors are replaced with Solid Perfect-Surface Copper (PSC+). The noise dissipation technologies used in the Yukons are a three-layered carbon-based material, but the same attention is paid to isolating the positive and negative signals and keeping them as even as possible.

The Yukons are designed, perhaps, for those who balk at the price of expensive cables while still craving noise dissipation and a distinct lack of a noticeable sonic imprint on the music. Unless I directly compared the Yukons to the Mythical Creatures and the Wind interconnects, I sensed no shortcomings in the overall sound. These are, indeed, a cost-effective way of hooking up components without “going overboard.” If I wasn’t a reviewer and I had to select an XLR interconnect for my mid-level audio system, I would choose these and never look back.

audioquest red river

xlr interconnect

AudioQuest Red River ($340/pr 1.5m)

The AudioQuest Red River XLR interconnects reminded me so much of the AudioQuest Rocket 33 speaker cables that I use as my “workhorse” cables. I use the Rocket 33s for breaking in components, and for use in second systems or bedroom systems. I also use them when I have amplification–British integrated amps, specifically–that have inputs and outputs and binding posts all crammed together in a very small space. The AudioQuest Rocket 33s fit into tight spaces.

When I use the Rocket 33s, I also find that I rarely have the sense that I’m losing anything compared to big, expensive loudspeaker cables. If I really dig in and listen carefully, I might hear something the big cables provide that the Rocket 33s don’t–perhaps a little more inner detail–but I’m always amazed that this $669 pair of speaker cables never feels like a sonic hindrance. I feel the same exact way about the Red River XLR interconnects. I never felt like like the Red Rivers subtracted anything from my enjoyment of the music compared to most of the other interconnects discussed here.

AudioQuest XLR Interconnect Conclusions

While this started off as an examination of the XLR interconnect to its RCA counterpart, it really evolved into a review of the AudioQuest Firebird and Thunderbird interconnects. That’s the real news here, that these two XLR interconnect cables are really special. They do make a huge difference in the sound. When I reviewed the CEC transport and DAC, I raved about those two components. When I reviewed the Burmester 101 integrated amplifier, I thought it exceeded my expectations in every way. What do these components have in common? I used the Firebird and Thunderbird XLR interconnect cables for both reviews.

I certainly don’t want to take anything away from CEC or Burmester, and I did use other interconnects during those reviews, but it’s pretty obvious that the Firebird and Thunderbird interconnects took the performance of these components much further than I expected. I won’t say that the AudioQuest XLR interconnect cables made them better than they were, as I’m a strict adherent to George Cardas’ view that cables don’t solve problems, they are the problems. The idea is to choose cables that introduce fewer compromises to the signal than all the other cables. The AudioQuest Firebird and Thunderbird XLR interconnect cables, to slightly different degrees, allowed more music to flow through the system to my ears than any other interconnect in recent memory.

As far the RCA vs. XLR debate, I fear the A/B protocols are fraught with countless variables that might keep me from discovering the truth. First, you need to find a component that offers both connections for the same function, such as that McIntosh amplifier that started this whole journey or the Ayre V-3 that has become my “workhorse” power amplifier. Second, I have to think back about what Gary Morrison said about amplifier having to assume to additional circuitry for XLR, which seems to introduce another undesired variable to the equation. In other words, I cannot offer you a conclusion on which one is “better.”

I think we have to go back to Bill Low’s original comments that the decision between XLR and RCA depends upon even more variables such as component design and system configuration. Here’s Bill Low’s final take on the XLR vs. RCA debate:

“I think the comparison between RCA plugs and XLR plugs is a red herring. Either can be lousy or excellent — and the sort-of comparison partly obscures the real issue as to whether single-ended or balanced will yield better performance with particular equipment.
“The SE vs. balanced comparison should only first be made with balanced cables that use identical conductors to the SE version — and with balanced cables that don’t cheat and use the shield to XLR pins on both ends, using the shield as the signal ground-reference. I don’t know just how common that still is (pretty much no-one uses the shield as the ground-reference for SE cables), but it could be an interfering variable that could wipe out the basic question about optimizing the interface between two components.”

That aside, the AudioQuest Firebird and Thunderbird XLR interconnect cables were simply stunning in my system, and Skip was completely correct about their superb ability to draw you into the music. The rest of the AudioQuest XLR interconnect cables also shine at their respective price points, and I think it’s more than likely you will find one that excels in your system, whatever your budget.

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