Yes, it's a waste of time. The adapters don't create a true balanced signal, and the result is the same as a single ended RCA connection. I don't know the K5x-e, but if it is truly balanced then the RCA inputs are basically wired as internal XLR adapters anyway.
41 responses Add your response
Yep, I agree with everyone else. Except what Ghostrider says is not totally correct. In fact the Ayre IS a fully balance piece, and in order to take advantage of that you do need to access its XLR inputs and ideally drive it with a balanced signal. If it is wired like my P5Xe phono stage, then the RCA inputs will drive the Ayre in single-ended mode; the RCAs are not wired "like the XLR" inputs. (My p5Xe has switches on the rear panel labeled "BAL" and "UNBAL". You throw the switch based on the input and use the relevant input jacks.) But read the manual on the K5Xe to be sure I am correct. I can only speak about the P5Xe. Its possible that the K5Xe will sound best driven via its XLRs, even though your source component does not output a balanced signal. Charles Hansen probably has an opinion on this. |
XLRs are often better than the best of RCA ICs, no worries there. Plus- all cartridges these days are balanced sources. The advantage of a balanced input on the phono preamp is that you can set up the phono system and run the signal balanced. If you have ever wondered why the phono is the only single-ended source that needs that extra grounding wire, its because it is actually a balanced source that you are trying to run single-ended. If set up balanced, the ground wire becomes the shield of the interconnect and the plus and minus outputs of the cartridge travel inside that shield. The result is that the cable is more impervious to noise and you can run it a longer distance, especially if you have a low output moving coil (due to the low impedance of the LOMC). The balanced cable system exists for the **sole purpose** of removing interconnect cable artifacts. You would think that audiophiles would be all over it for this reason; I suspect most people simply don't understand the benefits. |
If set up balanced, the ground wire becomes the shield of the interconnect and the plus and minus outputs of the cartridge travel inside that shield. The result is that the cable is more impervious to noise and you can run it a longer distance, especially if you have a low output moving coil (due to the low impedance of the LOMC). Well...while this may be conceptually useful, it's not strictly correct (nor how it's sometimes executed in the marketplace). Yes, the cartridge is a balanced source. However, the tone arm cable is sometimes not geometrically and electrically "balanced" - specifically, symmetric positive and negative lead surrounded by a shield. You'd think this would be the "default" cable geometry for tone arm cables - even with single-ended terminations. However, after ordering a "balanced" OL Silver w/ XLR terminations, I found out it is not (and I'm still irritated about this, but not enough to spend the additional money to have my tone arm cable replaced). Oftentimes, a "singled ended" cable is terminated with an XLR adapter and called "balanced". The problem with this configuration is you do not have a symmetric positive and negative lead surrounded by a shield, but a single hot lead surrounded by a shield. The shield is responsible for carrying the negative signal. Not only is the asymmetric geometry a problem, but the shield (that is carrying the negative signal) picks up RFI. And since the positive and negative signals are not polluted with noise equally, the balanced circuit design does not "remove" this noise. Atmashere is succinct spot-on when he says "balanced cable system exists for the **sole purpose** of removing interconnect cable artifacts." True, 'dat! |
Jimjoyce, The XLR connector is just a better design than an RCA one. Thinner pins for less eddy current problems, better contact, firmer connection, etc. This is not to say that ALL XLRs will sound better than ALL RCAs, because as you infer there has been quite a lot of development in RCA connectors, largely to overcome their inherent problems. BNC connectors are inherently way better for single-ended audio and should have been the standard, at least for high-end stuff. The RCA connector is only about convenience. Nrenter makes a great point. I recently found this out when I was ordering a DIN to XLR phono cable from a guy on eBay who makes them cheaper than what I have to pay for the individual parts. He had no idea how to construct a balanced cable, even though he is in the business. He built it to my specs finally, with separate but equal conductors for the positive and negative halves of the signal and the shield separately grounded. I have not done the research to determine whether this problem is common to even megabuck cables. (I paid $70 for the finished cables, which I then terminated myself with my choice of XLRs.) |
Nrenter, Its a fact that there are cable guys out there that have no idea how to execute balanced cables, especially ones for phono! Most arms that have a 5-pin connection are perfect balanced sources, as the wires are shielded by the arm tube itself. This includes all the old BSR, Garrard, Dual and other inexpensive 'tables from the 60s and 70s- they are very easy to convert to balanced without any mods to the arm at all. With newer arms that use the 5-pin DIN, its easy- just change out the cable. In fact it is even possible to set up an arm with RCAs for true balanced operation, as long as there is a grounding post and the RCA jacks are isolated from ground. We make a special cable for that. It can't be done if the arm ground is tied to the minus of one channel (which causes a ground loop), like you see in some air-bearing arms. BTW it is this ground loop issue which is why most arms employ 5 wires (the 5th for ground) rather than 4. |
Dear Gallant_Diva, You wrote, "XLR circuit has two to three times the complexity of RCA, not to take away the transparency and purity of the signal." That is the old argument for those who believe that single-ended circuits are per se superior to balanced ones, because of lower parts count. I think the argument is spurious, and I could tell you why but it would take too long. Anyway, in the case of the last few posts, we were talking about the relative merits of the two types of connectors (XLR v RCA), as connectors. |
Atmasphere, You gloss over many things that are not obvious (or intuitive) to the casual reader. I'm not restating to tell *you* anything you do not already know - just want to make sure everyone following understands the differences (subtle, yet very important). This topic seems to cause a bit of confusion. A "balanced" cable has nothing to do with the termination (XLR, RCA, bare wire, etc.). As Ralph said, a single "balanced" cable has a specific wire geometry - two identical leads (one positive, one negative) surrounded by a shield (ground). *Usually" a balanced cable is terminated by XLR, but you can't be sure without looking "under the covers". But this is the same with amp / pre-amp design - you can't assume it's a balanced design just because it has XLR inputs / outputs. While many arms ship with a 5-pin DIN connector (and makes it easy to swap in a truly "balanced" cable), my OL Silver did not. I did not want a DIN connector as I wanted a continuous piece of copper from my cartridge clips to my XLR terminations. Unfortunately, OL does not ship the Silver with a "balanced" cable, even when requesting a "balanced" tonearm (they just slap on XLR terminations on their single-ended wire, then charge you £330.43 plus £21.74 for new XLRs fitting for their Linear Flow 2 cable if you want it truly balanced). |
Let me rephrase the question: What XLR connectors do you (or anyone) view as equal to or better than an Eichmann silver RCA? Ignoring for a moment the preference for exotic materials such as silver and gold (and equipment failure, contact or design issues), one can say,in general, that ANY XLR connection will normally perform at least equal to and often better than RCA. Any good quality XLR from a guitar store (such as Mogami) should at least equal the best RCA. |
Jimjoyce25, the standard Neutrik will do the job. Its available in both silver and gold versions. There are of course exotic XLR connector varieties, but IMO/IME, if the balanced line is set up correctly, they don't make any significant difference. One way of looking at this- RCA single-ended cables strive towards a sort of goal of perfection. If the balanced connection is set up right, its already there; IOW the RCA will always be falling slightly short of what any balanced cable can do. This is not only because of the balanced aspect but also because of the fact that if balanced lines are set up correctly, they are *low impedance*. Low output moving coils play perfectly into this; nearly all are 'low impedance', i.e. they can *drive* a load of 600 ohms (or less) and sound **better** for doing so. |
It sounds as if the conclusions being voiced here are based more on philosophical creed, rather than on experimentation----at least not recent experimentation. Since either type of connector can be used on either type of cable, the comparison should be pretty straightforward. I've done the direct comparison of Eichmann silver vs copper RCAs. and in a good enough system, the superiority of the silver is quite clear. I'd be interested in knowing if anyone has done a similarly direct comparison between the Eichmann silvers and high-quality XLR connectors. |
Jimjoyce25 All the subtle design parameters, like cable geometry, purity of materials, conductors spacing, the use of platings in connectors and the like vanish as variables when you use the low impedance balanced line system. In high impedance single ended setups, all these things make a difference and bring you closer to the truth of the music, as you have experienced. IOW, in single-ended systems the cables are a sort of 'hidden cost' and are paramount to the performance of the cartridge or preamp in that system. In a balanced setup, the cable cost and impact it has on the sound is insignificant. In short (if done correctly, as we have seen from prior posts that is an issue) its a transformation to go from RCAs to balanced. |
I share Ralph's philosophy on this one. If you buy the right equipment and match it correctly then who cares about cables. Some equipment designs do not need $100's or $1000's of dollars of cabling to perform perfectly - nor is this type equipment necessarily less resolving. The important thing is to get equipment that is designed to preserve every detail on the recording while adding as little distortion or noise as possible and whilst minimizing the effect of all extraneous variables (cabling, operating temperature, AC power, humidity, RF/EMI interference etc. etc.) Equipment that is so sensitive that it is influenced by nearly anything and everything is a liability IMHO - it is simply not well designed for accurate audio reproduction of the source. Frankly, it is a bit of a travesty that the serious design challenges faced by world class audio designers to build outstanding components is even compared or discussed in the same conversation as an piece of wire with two connectors on the end. There are several orders of magnitude difference in the design & technology required by the component designer versus those simply making cables....but you would not know this from reading the marketing claims of those who just make cables. Some cables seem to run on some kind of 22nd century dilithium crystal technology... |
So, your view is that a properly designed balanced cable geometry is inherently better than any single-ended cable geometry, no matter what the design? Sounds like more philosophy to me, unconfirmed and untested by experience. Do you have a dealer in the San Francisco area who carries your equipment and has it set up with properly designed cables? At some point I'd be interested in doing a direct comparison with the very very simple single-ended design I have. |
Sounds like more philosophy to me, unconfirmed and untested by experience. Yes you are right. It is mostly the tin-eared folks in pro audio that exclusively use balanced XLR for everything. The philosophy of head bangers with PA speakers is meaty connectors that are unbreakable when used by gorillas. They would be unable to test anything in an A/B comparison anyway, as all of them are deaf from listening too loud for too long. |
JJ25, Keep us posted with what you learn. However, you do realize that your experement does not isolate your cable design as the only variable (which means your test will prove nothing). If you don't understand why, either you have not read the above posts, or you do not comprehend the above posts. There are no absolutes, and I am 100% certain of this fact. |
nrenter---My thought was to do the comparison between the preamp outputs and the amplifiers in the system. Obviously it couldn't be done in a simple and direct way on the front end. As it happens atmasphere's preamp has only XLR outputs. I don't suppose using the RCA tape outputs would make for an appropriate comparison? But let's suppose, as you suggest, that an appropriate comparison can't be done. Doesn't the position that balanced lines and XLRs are better just remain, as I suggest, an article of faith? shadorne: There are all sorts of reasons to use balanced lines in a pro audio setting: Long cable distances, greater potential for signal pollution, etc. None of which exists in the typical home audio set-up. Which suggests that experimentation, rather than philosophy, could be a better way to answer the question. From a rhetorical perspective, the dismissive attitude of so many of the posters here is remarkably similar to religious belief, or to beliefs about global climate change. It's an interesting question to try to figure out the psychological causes of such beliefs, but the beliefs themselves are merely that. |
Your response indicates you don't fully understand your test - and that's why your results will be meaningless. A great audio system is not a collection of optimized independent variables, but a collection of optimized dependent variables. That's what you're missing. The RCA vs. XLR debate is meaningless because the cable "performance" is dependent on the the circuit driving (and being driven by) the signal transmitted by the cable. Single-ended and balanced topologies are very different, and a balanced cable has less effect on a balanced circuit than a single-ended cable on a single-ended circuit. It isn't religion - it's physics and circuit theory (plus, some of us not only have EE degrees, but have spent time in recording studios, and designing audio equipment). Are you suggesting that your question is novel and no "experement" has ever been tried? If you have a collection of "optimized" independent variables that perform admirablably, then good for you. |
I used to "believe" that balanced cables were better because my electronics were balanced. Then a fellow Audiogoner suggested I try the single-ended output on my phono amp. It was clearly superior in my system. I contacted the manufacturer, and he said that he listens to his phono's RCA output and uses XLR everywhere else in his chain. In his phono amp, the single-ended circuit is simpler and sounds better. I still use 6M balanced cables from my pre to my mono blocks because of the long distance. I agree with those who suggest listening first (experimenting) to find the best results in one's own system. |
Nrenter, you got it exactly right. That is why I am careful to stress 'properly set up' and 'low impedance' as those things are critical to getting the performance out of cables in general and balanced lines in particular. Preamps with RCAs tend to have high output impedances which make them susceptible to differences in cable construction. Most of the high end audio does not recognize this simple fact, because most manufacturers are doing balanced because it is something trendy, rather than researching exactly what the benefits are are and in particular **how to win those benefits**. So as a result we have a lot of variable results that make the whole thing confusing. In the case of LOMC, since the cartridges are an inherently balanced low impedance source, and should be loaded by a low resistance for best results, balanced is a sort of no-brainer. A great deal depends on the input of the phono section; if not differential forget it, and a great deal depends on the tone arm wiring- if the ground is independent of the signal wiring (which in most arms it is, the exception being straight-tracking air-bearing arms), then there are no worries. |
JimJoyce25: It sounds as if the conclusions being voiced here are based more on philosophical creed, rather than on experimentation----at least not recent experimentation.Not sure how balanced cabling can be used with RCA connectors, at least in a way that preserves the benefits of a balanced interface. And vice versa as well -- what would be the point to making a comparison between connectors using unbalanced cabling terminated with XLR connectors? One or both of those alternatives seeming to be the experiment you are proposing, if I understand correctly. And it seems to me that in any experimental comparison between RCA and XLR connectors the differences will be vastly overshadowed by other variables. As Nrenter aptly put it, "A great audio system is not a collection of optimized independent variables, but a collection of optimized dependent variables." Variables in this situation that clearly, imo, would far outweigh differences between quality connectors of the two types include, for starters: -- Interface circuit differences at both ends, including the fact that in designs that have XLR connectors but are not "fully balanced" there will likely be an extra active stage in the signal path to convert between balanced and unbalanced (or vice versa). -- The fact that in most and perhaps all conventional designs the ground sleeve of an rca jack (and consequently the shield of the unbalanced cable that is normally connected to it), is common with both signal ground, chassis, and ac safety ground. Resulting in signal return currents flowing through that shield in common with extraneous ac-related currents and noise caused by leakage paths and parasitic capacitances in the power transformer and elsewhere, and also due to ground loops which are often present to some degree. Basically, if it is not clear, connecting balanced cabling via RCA's, and connecting unbalanced cabling via XLR's, makes no sense. And the suggestion in your last post of comparing RCA tape outs with XLR main outs, in order to evaluate connector differences, is, well, simply unworthy of comment considering all of the circuitry that is present between those points, most probably including the volume control. On the other hand, contrary to what was said in some of the earlier responses in this thread, it is conceivable (although not especially likely) that in some systems there may be significant reduction of noise pickup if an unbalanced output is connected to a balanced input via a properly implemented adapter arrangement. See figure 2.1 of this reference: http://www.jensen-transformers.com/an/an003.pdf Note carefully how the adapter cable is architected, with the "adapting" basically being done at the source component's output, and balanced cabling being used from that point forward. Note also that although its common mode rejection ratio is far lower than for the transformer-based interface arrangements shown in the subsequent figures, the 30db cmrr figure which is indicated as being typical at 60Hz is significant nevertheless. With respect to the op's question, I believe that a Cardas RCAM/XLRM adapter (RCA male to XLR male), followed by a conventional balanced XLR female to XLR male cable, would amount essentially to this same arrangement. I also suspect that comparable but probably much less expensive pro-oriented adapters, available from B&H Photo Video and many other sources, would provide similar performance, at least from a noise rejection standpoint. But whether the overall sonic result would be superior to, equal to, or inferior to the op's present single-ended connection scheme would pretty clearly have to be determined by trial and error. Regards, -- Al |
Sam, you're very welcome. And thanks very much for the link you provided to the Rane paper, in your post dated 11/24. It is indeed, as you said, very informative, and makes the point (among many other points) that a lot of balanced equipment is designed incorrectly in some of the respects we have been discussing here. That perhaps being one of the reasons for the disagreements that tend to arise about balanced vs. unbalanced, and perhaps being an underlying reason for some cases of sensitivity to cable differences as well, as Shadorne has often pointed out. Best regards, -- Al |
Gentlemen: There's much that I don't know about electronics, and I appreciate the information you provide. But perhaps one benefit of my situation is that I'm able to approach the listening experience with a bit less prejudice than some of you. And IME the various preferences expressed in this forum (tubes vs solid state, analogue vs digital) are often based on the limited experience of a set of listeners, and they don't hold up in the listening room. Nothing I've read so far persuades me that there is anything inherently superior about differential vs non-differential technologies. It still sounds like philosophy, or, in the case of atmasphere, philosophy plus a marketing plan. It's also quite clear, in general, and despite the various prejudices, that there is no direct correlation between electronics theory and the best sound: There's still so much that has yet to be discovered about how to reproduce sound, so much that is not understood about how the technology results in the listening experience. Anyone who suggests otherwise is a fool, or trying to fool someone else. For every one of you with an EE degree, there is someone else with an EE degree who believes something different. Fortunately, none of that matters. What I am in search of is a way to make a useful, practical, listening comparison between the two technologies, differential and non-differential. Yes, I understand that this is perhaps not possible on a component by component basis, but surely someone can suggest an appropriate way to listen to the best that balanced has to offer, so I can come to the only judgment that matters. |
Jimjoyce25, that's really a tough call. The problem is that you have to find a preamp that is single-ended, built to a certain built quality, and then have a differential preamp that is otherwise the same topology and build quality. There are no such products out there, so winnowing out the differences purely on if it is differential or not is nearly impossible. So your plan B is to listen to the best that balanced has to offerand compare it to the best the single-ended has to offer. Here are the actual (as opposed to theoretical) benefits of differential operation: *up to 6 db less noise per stage of gain. *distortion cancellation with each stage of gain. *rejection of noise common to both inverting and non-inverting inputs *superior rejection of power supply noise Here are the disadvantages: *50% more parts in circuit path *requirement of a minus power supply *less gain than single-ended Here are the myths: *signal path is more complex fact: its the same with equal number of gain stages *you need more gain stages fact: not if you don't make as much noise- 2 stages of gain might be 12db less noise than SE *equalization errors are magnified fact: anyone who says that has not tried it :) *'phase splitter argument' the idea that the signal gets messed up due to the differential amplifier splitting the phase. This comes from a fundamental misunderstanding of how differential amplifiers work. I know you see it as some sort of marketing plan on my part but I simply practice what I preach. BAT was an early customer of ours before going into business for themselves, we influenced ARC, Sonic Frontiers and host of others as we were the first to have a balanced high end product which was the MP-1 preamp. The fact that it is balanced has been the single **biggest** marketing problem that we have had with it! So in a nutshell balanced differential has been out anti-marketing plan :) ... anyway in recent years balanced has finally caught on so the MP-1 has become one of the top contenders in that field, due in part to our experience and also we control a patent in the area as well. |
Ralph, thanks for the comprehensive and excellent summary. In your list of "actual as opposed to theoretical" advantages of balanced operation, my feeling is that reduced likelihood of ground-loop issues is another advantage that merits explicit mention, although it is perhaps somewhat implicit in your mention of noise rejection. As can be seen from some of the posts earlier in this thread, it is not uncommon for audiophiles to discount the importance of noise rejection in a home environment, due to the short cable lengths and simpler setups relative to a pro or studio environment. But as we've seen in many other threads here at Audiogon, home systems with single-ended interfaces often encounter ground-loop issues involving low frequency hum and/or high frequency buzz, that would most likely not occur if the signal interfaces between components were balanced (due to the separation in balanced interconnections of signal return currents from ac-related currents that flow through the cable shields). That advantage would seem to be particularly pertinent to setups that have MULTIPLE dedicated ac lines powering the different components in the system. Best regards, -- Al |
I second Al, thanks Ralph! Your contributions a lot of weight. Although I have not built an amplifier for 25 years - I am glad to see that the tried and true electrical engineering principles remain on solid ground. There are plenty of textbooks that would support your statements - so no need to apologise for "tooting your horn" about your own rigorous design choices. What I will say is this....there are several reasons for the consumer audio industry to promote RCA single ended over fully balanced: It is hard to convince most consumers of the benefits of fully balanced and it is much cheaper to go the RCA approach. So RCA means a lower price point and/or more profit. The lower cost approach is so important that as you correctly point out...most equipment with XLR connections is not actually fully balanced (at the circuit level) |
Jimjoyce, Your dream of comparing single-ended to balanced under any sort of controlled situation is just a dream. What you could take from this thread are the tips about when you would want to use an XLR connector (in or out) and when it is a waste of time and/or possibly even a detriment. You probably would be best advised to take that information and use it if you are mixing true balanced and SE components in the same system. Otherwise, find what you like and listen to it, single-ended or balanced notwithstanding. Ralph's remark about the anti-market effect of balanced design reminded me of the time about 10 years or more ago when I was standing in a friend's listening room, which contained many megabuck pieces, and talking with some guys who were in the high-end interconnect business. When they found out I had a balanced preamp (the MP1) they looked at me with nothing short of pity. Didn't I know that a balanced circuit could not possibly sound as good as an SE one, because it had too many parts? I had to walk away to keep from laughing, but there was no reasoning with them. |
