It’s a red herring, really and you’ve already acknowledged that AES48 is not commonly accepted in home audio. You describe your MP-1 preamp as "featuring Balanced Differential Design®" and state it’s "still one of the very few preamps to support the balanced standard (AES48)." You then go on to insist that only AES48-compliant designs are "proper" balanced designs.
@cleeds How is that a red herring?? The topic of this thread is "Balanced vs RCA preamps" so my comments about balanced operation are relevant.
I do describe the MP-1 and the MP-3 in that manner. I’ve described other high end preamps in that manner too.
The emphasis added bit is false.
Nor am I claiming they are The One True Way (in fact listed a couple of other ways including links in prior posts which you seem to be ignoring) nor did I say any competing balanced line product isn’t ’proper’. Please stop trying to put words in my mouth; when you do so you commit a logical fallacy called a Strawman; logical fallicies are false by definition...
Regarding the use of ’proper’ I was talking about driving a balanced line ’properly’. I didn’t say anything about some balanced line product not being proper. Do you get the distinction??
Again, for like the 4th time already(!), this is what I claim:
if AES48 is not supported, then you loose a lot of the benefit that balanced line operation offers: immunity to ground loops and reduced or non-existent cable coloration/interaction issues (this being the ’cable makes a difference’ phenomena).
Nowhere in that is any comment about anyone’s particular balanced preamp or the like. Its a simple statement about balanced lines themselves.
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atmasphere
That's the thing: it is commonly accepted (would you like an industry list?)
It's a red herring, really and you've already acknowledged that AES48 is not commonly accepted in home audio. You describe your MP-1 preamp as "featuring Balanced Differential Design®" and state it's "still one of the very few preamps to support the balanced standard (AES48)." You then go on to insist that only AES48-compliant designs are "proper" balanced designs.
So yes, you're here to promote your products, Ralph, and that's fine. You've earned the trademark and multiple patents and you've earned the right to tout them. But when you insist that you have found The One True Way, and that competing balanced designs aren't "proper," it warrants a reminder that with most things in life, there's almost always more than one way to accomplish a task. And that is certainly true in high-end audio.
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It cannot possibly be a "standard" ("something established by authority, custom, or general consent as a model or example") yet at the same time not commonly accepted.
@cleeds  That's the thing: it is commonly accepted (would you like an industry list?); not sure if high end audio designers chose to ignore it or are simply ignorant of it.
Just so we're clear, other than our own, I've never put that trademark on any website. As far as I know, that sort of thing might be considered a violation of forum rules.
If you want a speaker to work right you have to pay attention to Thiel Small parameters, for a USB cable you support the USB specs, for balanced line its AES48.
No, balanced lines can work quite nicely and still reject AES48. You're welcome to listen to my mostly-ARC system and judge for yourself, @atmasphere.
Thanks!. Just to be clear though, I never said or implied that if you don't support AES48 that it won't sound 'quite nicely'. What I did say was
if AES48 is not supported, then you loose a lot of the benefit that balanced line operation offers: immunity to ground loops and reduced or non-existent cable coloration/interaction issues (this being the 'cable makes a difference' phenomena).
My DAC at home sounds 'quite nicely' but it doesn't support AES48. So I keep its cables short to minimize cable colorations.
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AES48 is an industry standard but you'd have to check with them to see. As far as I can tell, a good number of them don't know what AES48 is.
It cannot possibly be a "standard" ("something established by authority, custom, or general consent as a model or example") yet at the same time not commonly accepted. Even your website admits that few home audio manufacturers observe this "standard." ("still one of the very few preamps to support the balanced standard (AES48)"
You mistake my reason for being active on threads where balanced line is discussed.
I don't think so. While you provide information about balanced circuits, you are also promoting your patented and trademarked Balanced Differential Design® components. That's fine, of course, but there's no reason to be coy about it. After all, you frequently argue that only balanced designs that respect AES 48 are "proper."
If you want a speaker to work right you have to pay attention to Thiel Small parameters, for a USB cable you support the USB specs, for balanced line its AES48.
No, balanced lines can work quite nicely and still reject AES48. You're welcome to listen to my mostly-ARC system and judge for yourself, @atmasphere.
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But it is just as opinion, and one which many of the world's foremost manufacturers of audio equipment reject.
@cleeds I'm not sure that's true; AES48 is an industry standard but you'd have to check with them to see. As far as I can tell, a good number of them don't know what AES48 is. I've seen manufacturers state their gear supports AES48 but then you found out it really doesn't. That makes me wonder if they know what it is.
You mistake my reason for being active on threads where balanced line is discussed. The simple fact is I've been doing this longer than anyone else and I've seen an awful lot of misinformation online. Apparently if I don't say something, the chances are high that no-one else will step in and set the record straight. Would you prefer that I just don't participate?
Just to be clear WRT to the 'one absolutely right way' remark, I didn't make this stuff up. We use a direct coupled technique in our products, transformers have been in use for the same purpose for the last 70-some years and That Electronics makes a chip at the link that is an example of the other way to drive balanced lines properly. There may be more ways but I am not aware of them and would love to be enlightened- after years of doing this, these three methods are the only ones I know of.
You are correct that my way isn't the only way. Before we introduced balanced lines to high end audio the only balanced products you came into contact with was studio gear. To be clear, the innards of the product doesn't even have to be balanced. My Ampex 351 tape machine was single-ended inside. That machine was the recording industry workhorse from about 1957 to well into the 1960s.
I am not denigrating anyone else's work; I think you misunderstand. Instead what I am saying is that if AES48 is not supported, then you loose a lot of the benefit that balanced line operation offers: immunity to ground loops and reduced or non-existent cable coloration/interaction issues (this being the 'cable makes a difference' phenomena).
No-one would argue stating that you don't have to support the USB standard for cable because such a cable might not even work. Balanced lines are different in that they will still play despite the standards being ignored, much like speakers in this regard; you can throw some drivers in a box but unless you did your homework its unlikely to sound right. If you want a speaker to work right you have to pay attention to Thiel Small parameters, for a USB cable you support the USB specs, for balanced line its AES48.
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... the idea that the output impedance of a balanced source is twice as high is true only if the balanced source isn’t designed properly to drive balanced lines! ..
That is your opinion, and you're certainly entitled to it. You express it here frequently, as is your right.
But it is just as opinion, and one which many of the world's foremost manufacturers of audio equipment reject. That appears to trouble you greatly, perhaps because you seek to promote your trademarked and patented Balanced Differential Design® components. And that's fine, too. But when you claim that those whose circuit topologies don't embrace your favored methods somehow aren't "proper," you really make yourself look kinda silly, imo.
I have a lot of respect for you Ralph, as do many others on this forum. But for just about everything in life, there simply is no One Absolutely Right Way, and that includes the design of balanced circuits.
I'm telling you this Ralph because I think you do yourself a disservice by denigrating the designs of others.
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The resulting voltage is the so-called differential voltage, which is twice the amount of the individual phase voltage. This explains why the voltage from an XLR port is twice that of its RCA counterpart.
@lanx0003 Actually this isn’t true if the source is AES48 compliant.
An output transformer is a good way to look at this if you understand how they work. In the case of a an output transformer driving a balanced line, there is a simple secondary with no taps. One end of the secondary output is tied to pin 2, the other end to pin 3. Pin 1 is typically tied to chassis.
Now if you want to run this output single-ended, pin 3 is tied to pin 1. You’ll note that the actual output Voltage is unchanged as is the output impedance. IOW either way the Voltage and impedance of the source is the same, which is to say there’s no 6dB increase when running balanced as opposed to single-ended. The transformer doesn’t care if one side is grounded or not. Your conclusion in the quote above is false WRT AES48 compliant sources, such as our MP-1 or MP-3.
Now if you have a non-compliant source (such as a Topping DAC or ARC preamp) then your comment is true.
But that isn’t how balanced lines are supposed to work. Here is a link to a Neumann microphone. Note the output impedance and the load its expected to drive (1KOhm). This mic is set up to drive balanced lines properly. A device that behaves as you described above does not.
Put another way, the idea that the output impedance of a balanced source is twice as high is true only if the balanced source isn’t designed properly to drive balanced lines!
To understand this issue better take a look at this page on the Rane website- its a quick read. If you scroll down to the ’Absolute Best Right Way To Do It’ you’ll see I’m not making this up. You might also read portions of this book by Bill Whitlock who designed most of the Jensen transformers. It gets more relevant to this discussion on page 13; if you look at the diagrams which show balanced connections, you’ll see no connection to ground except when it goes single-ended (such as driving an opamp in the case of an input transformer). Page 15 shows a microphone input. Page 16 shows a line output. I think you’ll see what I’m talking about.
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You have to be careful about things you read like the specs above! I own the two of the Topping DACs; The 40 Ohm value is actually the two 20 Ohm output impedances put in series when really they should be in parallel, which would be about 10 Ohms.
@atmasphere One should be very careful when interpreting the impedance of a true balanced XLR cable. The two conductors (pin 2 and pin 3) carry both positive and negative signals from the source to the load simultaneously, behaving like a parallel connection. However, because they are of opposite polarity, the signals travel in differential (v.s. common) mode. The resulting voltage is the so-called differential voltage, which is twice the amount of the individual phase voltage. This explains why the voltage from an XLR port is twice that of its RCA counterpart.
Similarly, the resulting impedance, known as differential impedance, is also twice the impedance per phase. The manufactural reports either impedance per phase or the differential impedance. Hope this helps.
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atmasphere
It is a fact in high end audio though that most producers of balanced line products pay no attention to AES48 (the balanced line standard) ... That is part of the reason there is a balanced vs RCA debate.
Not really, the benefits of balanced designs are pretty well known. Designing to the AES spec is just one approach to balanced design.
...the Topping DACs; The 40 Ohm value is actually the two 20 Ohm output impedances put in series when really they should be in parallel, which would be about 10 Ohms. WRT to the ARC stuff they are doing the same thing.
The Topping and Audio Research schemes are different than your designs. That doesn’t make your design right or "proper" any more than it makes the ARC design "improper," as you’ve claimed. They each take a different approach to balanced amplification, either method offers improved CMRR. (Similarly, some speaker designers use sealed boxes, some use ported boxes and some use no boxes at all. Each approach can be valid and its success will depend on implementation.)
The standard for balanced line studio line level input impedance is 600 Ohms ... Our MP-1 preamp can drive 600 Ohms directly ... Most tube preamps will fall flat on their face trying to drive loads like that. In fact most solid state RCA preamps will too.
Most home users have no need to drive 600 ohm loads.
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Where did you get this from? Have you done your homework before taking 10 seconds to write this? Let me do some homework for you, and you can do the rest to see if you can find anything to support your false statement.
| DAC |
XLR |
RCA |
| Topping Pre90 |
40 |
21.5 |
| Schiit Freya+ F / Kara |
600 |
75 |
| Audio Research LS17 SE |
600 |
300 |
| Audio Research 6 SE |
600 |
300 |
@lanx0003 It is a fact in high end audio though that most producers of balanced line products pay no attention to AES48 (the balanced line standard), or the use of dBm levels (more later). That is part of the reason there is a balanced vs RCA debate.
You have to be careful about things you read like the specs above! I own the two of the Topping DACs; The 40 Ohm value is actually the two 20 Ohm output impedances put in series when really they should be in parallel, which would be about 10 Ohms.
WRT to the ARC stuff they are doing the same thing. FWIW ARC preamps in general tend to have high output impedances.
IOW this is a nomenclature issue, not an output impedance issue.
The standard for balanced line studio line level input impedance is 600 Ohms. Common accepted good design practice is that the circuit driving a load like that will have an output impedance about 1/10th of the load impedance. So we can assume that the source impedance will be 60 Ohms or less. That's a lot lower than most single-ended preamps...
Balanced line levels are usually expressed in dBm. dBm is the VU reading you would get on a VU (Volume Unit) meter when the meter is across a 600 Ohm resistor. So its a measure of power; that requires the output impedance to be even lower. There are two levels that are standards in use: -4dBm and +10dBm; 0dBm is one milliwatt dissipated into a 600 Ohm load.
My Neumann U67 microphones are designed to drive a 150 Ohm load. That implies an output impedance of 15 Ohms.
Our MP-1 preamp can drive 600 Ohms directly at +10dBm despite using a vacuum tube output. This also suggests a low impedance and in fact they will drive 32 Ohm headphones.
My old Ampex 351 studio tape machine was designed to drive 600 Ohms and also supported +10dBm.
Most tube preamps will fall flat on their face trying to drive loads like that. In fact most solid state RCA preamps will too.
My Otari MX70 1" tape machine has 600 Ohm inputs which expect at least -4dBm. You need a low impedance output to drive that.
I designed the first balanced line preamp offered to high end audio back in the 1980s so yes, I researched this quite a lot prior to saying what I did  , and yes, balanced outputs generally are usually lower output impedance unless the manufacturer had no intention of supporting common balanced line practices.
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My preamp has both, XLR Lundahl balanced inputs transformers, since most Digital front ends are balanced ,then on the outputs RCA Because of Linear Tube Audio,originally Designed by David Berning with his unique Micro-Z-OTL output stage ,which the Vacuum tubes run much more efficient ,lower noise ,The team at LTA found over a few years to make it even better a Gen 2 Version , and use the Rays Select 6SN7 vacuum tubes , detailed a bit warmer , and the other tubes 12AT7 or 12AU7 which I am using with some Very rare Medical grade Telefunken tubes a great combo , + using 2 Hifi tuning Supreme CU- Copper Gold - 4 amp 20 mm slow blow fuses on back ,which VH Audio Carry.
and as a good option ,and not too expensive a Hifi tuning Supreme Silver gold 20 mm 3.1 amp Fast blow on the main board
with a AQ Tornado Source power cord ,Exceptional results and a who who of Excellent top notch parts quality which I know very well ,having 40+ years in Audio ,beating preamps at 2x the price $6350 Retail ,Mike at Audio Archon was very helpful , and fair-in pricing.
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@atmasphere Usually XLR outputs have considerably lower output impedance than RCA outputs.
Where did you get this from? Have you done your homework before taking 10 seconds to write this? Let me do some homework for you, and you can do the rest to see if you can find anything to support your false statement.
| DAC |
XLR |
RCA |
| Topping Pre90 |
40 |
21.5 |
| Schiit Freya+ F / Kara |
600 |
75 |
| Audio Research LS17 SE |
600 |
300 |
| Audio Research 6 SE |
600 |
300 |
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@riie
Of course, that depends on how level your shelf is
LOL
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If your preamp is not balanced, it might start sliding and fall of the shelf so I would always go with a balanced one
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A word of caution. Just because there’s an XLR connection does not mean it is a truly balanced circuit. I’ve seen many implementations where it’s actually a single ended circuit transmitted via XLR connectors.
@jpan , if the manufacturer clearly states that a piece of gear is truly balanced, I am willing to take his word for it.
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@Jpan Could be.... but it's true.
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Another reason for RCA and fully balanced XLR outputs might be for subwoofers. If the two sets of output jacks (XLR and RCA, respectively) are in parallel- meaning they both output the same audio signal, they can be used for connection to multiple amplifiers or an amplifier and a pair of mono subwoofers. My XLR outputs can connect to my amps XLR inputs and RCS outputs to my pair of subs.
I am not running my sub at the moment; however that's the way i ran it out of my SLP 05. I used the balanced in from my Marantz SA10 and the balanced out to my Cary V-12 and ran the sub from the RCAs out of my SLP05. The quality of the sub I was using left a lot to be desired, but it worked fine.
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"With that said, both boxes have single-ended connections as well to appeal to a broader marked. Why? Many sources are single-ended (ex. my Zest phono-pre is single ended output only, so the cable going into the ARC line-pre must be single ended)."
Another reason for RCA and fully balanced XLR outputs might be for subwoofers. If the two sets of output jacks (XLR and RCA, respectively) are in parallel- meaning they both output the same audio signal, they can be used for connection to multiple amplifiers or an amplifier and a pair of mono subwoofers. My XLR outputs can connect to my amps XLR inputs and RCS outputs to my pair of subs.
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@atmasphere Had to look up supporting AES48 and found this. Thank you! Go to the head of the class. Heck, you could teach it! I don’t know if the RCA or XLR’s outputs support AES48 in the Raven Pre? I don’t think Don Sachas/Lynn Olson who designed the Raven preamp hang around on Agon so I don’t think a comment will be forthcoming.
While I absolutely appreciate it; the advanced technology of audio isn’t something I ever wished to delve into. I just want to bliss out.
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A word of caution. Just because there’s an XLR connection does not mean it is a truly balanced circuit. I’ve seen many implementations where it’s actually a single ended circuit transmitted via XLR connectors.
@rwwear — is that sarcasm?
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Balanced is only good if you prefer less noise.
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... I’ve seen some (shall we say) sophomoric ’balanced’ products offered in high end audio that had almost no CMRR at all ...
That's not surprising - there's quite a bit of mediocre audio equipment on the market. But to argue that balanced components that do not observe the AES spec are somehow "improper" is misguided. They can still offer potential advantages over single-ended components, including improved CMRR.
... you’ll hear cable differences, the system will be subject to ground loop possibility and you won’t be able to drive long cables ...
I'm not having those problems with my mostly ARC system, which is not AES compliant.
As an aside, I'd wager there are balanced, AES compliant components on the market that are easily bettered by some single-ended gear. As is often the case, the implementation is as critical as the topology or technology.
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To the OP, Balanced Audio Technology (BAT) makes several tubed preamps. Most of their models are solely balanced. Heck, "Balanced" is even in their brand name.
@mammothguy54 You might be interested to know that one of the founders of BAT, Steve Bednarski, was a customer of ours before BAT, and owned one of the first production Atma-Sphere MP-1 preamps.
Years ago I was yacking with Mr. Internet, Kevin Deal (he does know his stuff) and he said on the RCA/XLR question that component build quality is what matters.
Recently I swapped in/out RCA/XLR cables from source to pre and from pre to monos. My data set of one could hear no difference.
@wsrrsw If the balanced equipment doesn’t support AES48 you may well have heard no difference or even a degradation compared to the RCA connection.
I’d argue that noise reduction is the primary benefit of truly balanced circuits, which can offer high CMMR.
@cleeds Unless it doesn’t... I’ve seen some (shall we say) sophomoric ’balanced’ products offered in high end audio that had almost no CMRR at all. -Almost as if the designer didn’t understand what that Common Mode Rejection was all about.
Balanced equipment that isn’t AES compliant isn’t necessarily "improper," it’s just different. For example, the balanced ARC gear isn’t AES compliant, yet using the balanced connections yields improvement that you can measure and hear.
This is true. But you’ll hear cable differences, the system will be subject to ground loop possibility and you won’t be able to drive long cables. These problems were solved over 70 years ago! Imagine a recording studio where you may have 20 different audio devices connected together (although usually not all in the recording chain at one time). If you have a ground loop buzz it could take weeks to sort it out! Ground loops are an audio menace many audiophiles have dealt with; AES48 prevents that happening.
Imagine not having to worry if an interconnect cable is going to sound right- just plug and play with no worries. That too is a benefit of balanced lines if done right (usually you have to support being able to drive a 600 Ohm load).
I designed “balanced interconnect” by adding out and in fully isolating ground transformers, typ 50Ohm unbal. <=> 600Ohm bal. systems with RCA/DIN unbalanced outs and ins with excellent results!
@westcoastaudiophile +1 The venerable Ampex 351 tape machines (which were used to record a lot of the RCA Living Stereo catalog) were internally single-ended but used input and output transformers to interface with balanced connections.
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Will someone explain fully balanced.
Ground loops can exist even with a balanced connection. You may have to lift pin one.
Tubes or solid state can be balanced it just depends on how many tubes you want to use or if you want transformers.
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"it is not a good idea to base your decision on which preamp to buy solely on the basis of balanced outputs. First of all, they do not exist for tube equipment"
Perhaps some clarification regarding Balanced Tube Line-Preamps is in order...
I am currently running a Balanced Tube Line-Preamp (Audio Research Ref 6SE ) into a Balance SS Amp (Ayre V5). My understanding is BOTH boxes are fully-balanced (that is, they are not simply using XLR connectors, with single-ended circuitry). The cables are XLR terminated (High Fidelity Cables).
From the ARC marketing brochure: the 6SE is a fully-balanced, Class-A design with zero feedback."
If the hifi lore is true, the founding-fathers of both companies, William Zane Johnson (-2011) at Audio Research and Charlie Hanson (-2017) at Ayre strongly preferred designing balanced circuits for their equipment.
With that said, both boxes have single-ended connections as well to appeal to a broader marked. Why? Many sources are single-ended (ex. my Zest phono-pre is single ended output only, so the cable going into the ARC line-pre must be single ended).
Bottom line... Yes, you can buy a high-SQ Balanced Tube Line-Preamp that also has single-ended connections.
(my apologies if this was covered by prior replies, as I currently do not have enough time to read the full string)
Happy Hunting!
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@68pete "Just because you have balanced input and out puts does not mean the unit is full balanced!” +1
XLR isn’t only balancing solution possible! I designed “balanced interconnect” by adding out and in fully isolating ground transformers, typ 50Ohm unbal. <=> 600Ohm bal. systems with RCA/DIN unbalanced outs and ins with excellent results!
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The reason to use a balanced connection should be to eliminate ground loops and cable artifact.
I'd argue that noise reduction is the primary benefit of truly balanced circuits, which can offer high CMMR.
A proper (AES48) balanced connection will do that. Its worth noting that a lot of 'high end audio' balanced equipment does not support AES48 even though it's balanced.
Balanced equipment that isn't AES compliant isn't necessarily "improper," it's just different. For example, the balanced ARC gear isn't AES compliant, yet using the balanced connections yields improvement that you can measure and hear.
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First, as always, thanks to "atmasphere" for his input.
I would add that there are a number of considerations to address when buying a preamplifier. Connectivity being only one. Your system arrangement and placement of components is another important part. A good standard practice is to keep loudspeaker cables as short as practically possible. That leaves you with the interconnects. Any well designed & engineered single-ended preamplifier with a low output impedance (~200 ohms) should be capable of driving long runs of interconnecting cable. Choosing an interconnect cable shouldn't be left to chance.
For several years I used 30' runs between my preamp and my mono block amps with no hum or any other issue. My current arrangement in a new home is much different and my interconnects have stayed the same, but I just shortened them to about a meter in length. My mono block amps do not have balanced connectivity. If they had I may have tried both single ended & balanced interconnects especially if the amps were truly of a balanced design.
I would encourage you to home demo any preamplifier that you are considering before you purchase. Preamplifiers are a very important component in all things hi-fi. Afterall, it's all about the sound.
Happy hunting
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Just because you have balanced input and out puts does not mean the unit is full balanced! A very large part of the pre amp market is not fully balanced. Even though they have the connections.
True, @68pete , but I bet that almost every manufacturer that puts a piece of gear out with a truly balanced circuit comes out and says so in the owner's manual.
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Just because you have balanced input and out puts does not mean the unit is full balanced! A very large part of the pre amp market is not fully balanced. Even though they have the connections.
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The short answer to your question is, it is not a good idea to base your decision on which preamp to buy solely on the basis of balanced outputs. First of all, they do not exist for tube equipment, maybe there is a hybrid out there I am not aware of, but for all practical purposes anything with XLR connections is going to be solid state.
????????
@billstevenson , the Cary SLP05 is a tube preamp that features a truly balanced circuit, and I am sure that there are plenty of others.
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I think people who like balanced enjoy plugging in the cables more than RCA. They look really cool.
@emergingsoul , ever since I was in preschool I have been fascinated by balanced circuits and the effect that they had on my audio gear; therefore at recess I would always sneak out to the nearby audio store to check out how much better the truly balanced circuits sounded than the single ended.
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To drop noise floor, I prefer balanced.
For checking out tube amps including flea watt which usually have a higher noise floor, I’m indifferent. I’m mostly concerned with the sonic profile offered by tube amplification
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Back to the Spatial Audio Lab Raven tube Preamp it is fully balanced and dead quiet. If you don’t need a lot of output power their suite (mono’s & pre) punch far above their cost. Like wow….Ahyho…
Years ago I was yacking with Mr. Internet, Kevin Deal (he does know his stuff) and he said on the RCA/XLR question that component build quality is what matters.
Recently I swapped in/out RCA/XLR cables from source to pre and from pre to monos. My data set of one could hear no difference. As for my build quality, that’s another matter. Lifetime guarantee? Who’s lifetime?
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To the OP, Balanced Audio Technology (BAT) makes several tubed preamps. Most of their models are solely balanced. Heck, "Balanced" is even in their brand name. However, the model VK-80 has two balanced inputs and three RCA inputs as well as balanced and RCA outputs. If you are looking to buy a used preamp, their model VK-33SE is the predecessor to the VK-80 and has the exact same inputs/outputs. I owned the VK-33SE and can speak for its sonic excellence as well as build quality. I made a step up in the BAT product line and now have the VK-90. Highly recommended as a brand of excellence in all regards.
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For the most part it's purely bragging rights. XLR connections when fully and correctly implemented can reduce noise and eliminate ground loops.
In some circumstances this can be huge, but for most of us it's minor.
Also, as others note, if you are using very long runs to other devices with truly balanced inputs this is helpful in ensuring there's no noise pickup along the way. Some devices, like some Parasound amps as an exmaple, have XLR inputs as convenience but they are not balanced inputs, so you don't get the benefit of a long run with less noise.
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@atmasphere
Clearly with such a long distance for a cable, a balanced XLR cable makes sense. RCA connect going out that long is never really a good idea. Interesting speakers horns are deserving of a look next time I buy a speaker
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@emergingsoul I like it
I have one of our MP-1 preamps driving about 35 feet of balanced cable which connects to the amplifiers. The tonearm has a balanced connection to the preamp as does the DAC. My tuner is old school so its a single ended connection to the preamp. The speakers are Classic Audio Loudspeakers model T-3s which are 98dB 1 Watt/1 meter, 16 Ohms and flat to 20Hz.
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@atmasphere
Amazing commentary you have. I bet you have a really really cool system.
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First of all, they do not exist for tube equipment, maybe there is a hybrid out there I am not aware of, but for all practical purposes anything with XLR connections is going to be solid state.
@billstevenson This statement is false. You might be interested to know that the first balanced line preamp offered to high end audio was the Atma-Sphere MP-1, which we still make. It has an all-tube signal path. FWIW, balanced line equipment first appeared in the 1950s, although back then output transformers were used to produce the balanced inputs and outputs. Our MP-1 is transformerless- we patented a method of direct-coupling instead.
When using XLR connectors be aware that Japanese audio manufacturers use a different configuration for pin for ground.
@toronto416 Its more likely they have pin 2 of the XLR wired as inverting and pin 3 non-inverting (which is opposite of US products). In all countries pin 1 is always ground.
The only potential adverse impact is that the output impedance of the XLR connection might be 2-3 times high. If you have an amplifier with low input impedance, such as a valve amp, you might run into impedance matching issue.
@lanx0003 Usually XLR outputs have considerably lower output impedance than RCA outputs. Its typical in a balanced line setup to see input impedances as low as 600 Ohms (which most modern opamps can drive) although in high end audio input impedances can be 10K to 100K. Our tube preamps can drive 600 Ohms no worries.
balanced in my view relates to when you have really long cable runs which many of us do not.
@emergingsoul The reason to use a balanced connection should be to eliminate ground loops and cable artifact. A proper (AES48) balanced connection will do that. Its worth noting that a lot of 'high end audio' balanced equipment does not support AES48 even though it's balanced. The benefit is there even if the cable is only 6" long.
My understanding is, by definition, single-ended-triode (SET) operation involves amplifying the entire signal with only one output device. A balanced circuit cannot be built this way. But I may be incorrect.
@dseltz Actually an SET has a differential input (but isn't balanced). Most of the time that input amplifies what is different (hence the name 'differential) between the RCA jack and ground. In case you're wondering, the other input to the input tube is the cathode. One way you can tell the input is differential is that if the grid and cathode are tied together there will be no amplification. If your preamp has a balanced output and has an output impedance low enough to drive the cathode, it is possible for the SET to receive and process both phases of the balanced signal. It won't be balanced, but it will be in the differential domain.
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+1 maxdukecapone
I own the Arik Audio Motherload XL. Balanced following the AES48 standard, also with RCA. It is a well made, beautifully sounding pre-amp. And dead quiet. I have two amps, the Atmasphere Class D (a beautiful pairing) as well as a Radu Tarta SET 45 amp. These also sound wonderful together, but a SET does not have XLR inputs (AES48 standard). My understanding is, by definition, single-ended-triode (SET) operation involves amplifying the entire signal with only one output device. A balanced circuit cannot be built this way. But I may be incorrect.
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VAC, BAT, Atma-Sphere & Aesthetix all make tube preamps that are truly balanced. Most BAT models have only balanced inputs & outputs. My VAC has both types. Cheers,
Spencer
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Balanced interface is superior to single ended, not matched impedance RCA (or DIN) one, because:
1) truly balanced (not pseudo) interface has common mode noise rejection, which eliminates / reduces noise between two connected devices chassis / gnds, RCA (or unbalanced DIN), transfer all noise to the signal.
2) balanced interface, originally designed for 600 Ohm driver / receiver impedance match, eliminates problem of time delayed signal reflections from original signal, thus enables long cables w/o tangible signal quality loss).
3) balancing in RCA or other single ended interconnects can be achieved by adding isolating / balancing transformers, but good performing transformer is costly.
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I think people who like balanced enjoy plugging in the cables more than RCA. They look really cool.
I have a Conrad Johnson gat2 preamp which does not offer balanced. by Having both balanced and unbalanced to me means they gotta spend more money duplicating circuits and I would prefer they spend even more money on one circuitry related to the unbalanced. Why spend money on stuff you're not gonna use and after all, balanced in my view relates to when you have really long cable runs which many of us do not. But they are really cool to plug-in.
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When I had an all Aesthetix system I used XLR cabling. Fast forward to current day and my complete Conrad Johnson system, as all CJ gear, is single ended. I have no issues with noise and the sound is fabulous. My cabling is all Audience Front Row.
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RCA or XLR preamp? If you have a power amplifier with balanced IN, surely the preamp with XLR in-out would be good choice.
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I always use an XLR connection because, in my experience, the sound is better (with volume matched) than the unbalanced outputs.
If the design is truly balanced, the higher output level from XLR can generally contribute to better sound (again, when volume matched) due to a higher SNR and lower noise floor in terms of THD+N. Apart from the well-known benefit of better noise rejection, handling the signal path separately for + and - significantly reduces crosstalk (see below).
The only potential adverse impact is that the output impedance of the XLR connection might be 2-3 times high. If you have an amplifier with low input impedance, such as a valve amp, you might run into impedance matching issue.
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@billstevenson a tube preamp can be differentially balanced and even be direct coupled.
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