Why I enjoy my Luminous Audio passive unit, vs an additional gain stage ( preamp )


This topic of preamp / passive, has been discussed, ad nauseum. So why am I posting this ?, you ask. Why not, as it is still be discussed heavily here, and elsewhere. This is a short story ( lol ), but a quick read, so be patient, and thank you, in advance, for reading. In the early eighties ( I am thinking ’84 ), PS Audio introduced the model IV preamp, which had a button on the left side of the faceplate, that showed...Gain...active / passive. Interestingly, a year or 2 prior, the CD was introduced. Prior to the cd, we audiophiles and music listeners, listened to vinyl, open reel tape, radio ( tuner ) cassette tape, and in my case, worked a bit with microphones, patch bays, mixing consoles, and dabbled in live recording ( early on ). As most of you know about me from my posts here, I own Klipsch Lascalas ( tweaked and modified ). I met Paul Klipsch, and was, from my very early beginnings, a Klipschaholic. My dad had AR3a’s, driven by a Fisher 500C. My music teacher / singing coach, had Klipsch Cornwalls ( the mid and hf horns were vertically mounted, mirror imaged, and were the only pair I had ever seen with this vertical arrangement ), which soon became mine, as he upgraded to the Khorns. My dad no longer wanted tubes, so he purchased a Sansui 8 Deluxe, and I, the 500 C. Wow !. We were both happy. The Sansui was so much a better match for driving his power hungry ARs, and I was happy with my combo ( this was the late 60s already ). Moving along to the CD era, the typical cd player, produced 2 volts output, which was enough to drive most power amplifiers directly ( just needed a way to control volume ). The early cd players, were large and heavy, and they had, as part of their designs, massive transformers and huge, hefty power supplies. Sony, if I remember (and I could be wrong ),was the 1st company, who offered a variable audio output on their players, and we, the equipment consumers, bypassed our preamps, and were running these cd players, even through receivers and integrated amps, that allowed the disconnect between the pre and power sections, going direct into the power amp sections. Getting back to the introduction of the PS Audio model IV preamp, and its gain switch. This began an onslaught of passive devices ( volume controls / switching units ), without a gain stage, to hit the market. Moving along to modern day, there are hundreds of passives available. Some dac manufacturers claim, they can drive amplifiers directly. As it turns out, within the last several years, manufacturers are now producing integrated amplifiers, sans a preamp gain stage, taking the signal of the source ( not just cd players and dacs ), but tuners, tape machines, computers, phones, outboard phono stages, cable and satellite boxes, etc., and driving the power amp directly, without the need for the extra gain stage. What I want to tell you, is this. With the right system ( and I will use my system as an example ), an extra gain stage ( preamp ), does more harm, than good. A longer signal path ( more parts, more wires, more circuits ), can only destroy finite details, can only add colorations, can only add distortions, if GAIN IS NOT NEEDED. I used to feel this is in part, to the very high sensitivity of my loudspeakers, as any of my ( what remains of my collection ) 20 or so power amps, runs them so very easily. However, I have introduced many folks to the passive band wagon, taught them what to listen for, helped them with their systems, and now, enjoy passive listening. With all types of systems. Jumping back to my Luminous Audio unit ( I am using their top single ended model, but they all share similar topology ). This is a fixed series / variable shunt device. What this means is, the signal never passes through the volume control. The signal travels through 1 high quality resistor, and the amplifier’s inputs are shunted to ground, via the potentiometer, itself. The resistors can be selected, as well as the potentiometers, depending on the model, and Luminous will impedance match your particular unit, to match your system. For a nominal fee, it can be sent back to Luminous, and be designed to match with other / different gear. The beauty of my passive unit, is, that I do not " hear it ", in my system. It is NEUTRAL. Another term popularly used, is COLORLESS. How I know this. Using a self modified Yamaha pro amp from my collection, which has input attenuators ( as all pro amps do ), I hear no difference between my dac feeding the amp directly, vs the Luminous in the system ( although, I do hear the additional 1/2 meter Audio Research Litz interconnect, needed, with the passive ). Yes, this cable has a sound ( all cables, ime, do ). I am not getting paid by Luminous, by Klipsch, by anyone, posting this. Lastly, 2 more things. I have heard a few systems, in which an active preamp was beneficial ( the added gain ), but, to my ears, some neutrality was lost. I also greatly believe ( besides the source needing to have the proper output voltage and matching impedance ), the source, whatever it would be ( let’s say a dac ), should have a very hefty, over designed, stiff and well regulated, power supply, as part of it’s analog output section, based on my listening ( many do not ). I am open to further discussions on this matter, invite questions, and share experiences. Enjoy, be well and stay safe. Always, MrD.
mrdecibel
I hear no difference between my dac feeding the amp directly, vs the Luminous in the system ( although, I do hear the additional 1/2 meter Audio Research Litz interconnect, needed, with the passive ). Yes, this cable has a sound ( all cables, ime, do ).
If you can hear the additional cable, it follows then that you are also hearing the cable that you are using to hear that other cable.


If you want to get off of the cable merry go round, the way to do it is to go balanced line, and use equipment that supports the balanced standard. If your Yamaha is really meant for professional use, it has balanced inputs that support AES48, the balanced line standard.

That standard cannot be supported by a passive device unless a transformer is involved. In addition, not all line stages are identical, some are as good as the ones you've heard (not as good as passives) and others are much better (and better than passives). You might want to look into this topic in greater depth; if you have a good line stage that supports the balanced standard, then the 'sound of interconnects' goes away and you can have even greater transparency.
@atmasphere Welcome to my post, and thank you for the feedback. My other cable is in fact another of the same cable, and of the same length. I like the sound of these cables. I am yet to hear a cable that does not have a sound ( after an extensive break in ( another topic I will discuss at some point, also ad nauseum ). If I like something I put in my system, I give it some break in time, but generally do not need much time to make my final judgements. My Yamaha amps ( and other pro amps ), with it's input attenuators, easily allows me to hear the quality of a preamp, or passive unit, because I can go source / dac direct into it. My currently enjoyed amp at this particular time, is an original Edge M8, by the 1st company of Tom Maker. It is single ended, only. His newer stuff, Maker Audio, is balanced, and I am familiar with balanced connections, and the benefits of use. I totally went over this amp, and it is a dream to listen through. As we have discussed before on other preamp / passive threads, we always differed in opinion on this subject. Georgehifi is another, who is in my camp. I am completely fine with this, as I know many prefer a preamp, but few, ime, actually need one. As far as cables are concerned, and I am speaking of balanced cables as well, they all have different SQ characteristics, from each other, and from the various levels within the same brand. Power cables ( I build my own ), that will be another discussion, also discussed ad nauseum. There is a YT video, from " The British Audiophile ", " Hi Fi Cables, Myths and Misconceptions ", which is very informative. He is intelligent, and speaks with etiquette, as I find most Brits. I am glad you stopped by. All is good with our differences of opinion. As you may know, since my beginnings here on the ' Gon, I have always stated what SQ characteristics I enjoy, and I understand more than most, the variety of listeners that there are. It is what makes our audio world go round and round. Enjoy, be well and stay safe. Always, MrD.
As far as cables are concerned, and I am speaking of balanced cables as well, they all have different SQ characteristics, from each other, and from the various levels within the same brand.
One of the reasons for balanced line is that it is a technology that virtually eliminates artifact from the cable itself. But if the equipment used with it does not support the balanced standard, you will certainly hear different sound qualities from various cables! FWIW, a passive balanced volume control system (at least none that I know of) can support the balanced line standards because it has to reference ground in order to work. When you are running balanced line, ground is supposed to be ignored. This is why (until we came along) if a system supported the standard, transformers were in use. Transformers allow the circuit driving the balanced line to not have any connection to ground.

So the logical inference here is that the equipment you've heard so far simply does not support the standard. Beyond that though it appears that your method is pretty sound.
All good. I have heard the Benchmark gear ( at another listener’s home ), which I understand conforms 100%. We did a cable shoot out, and the sq differences between cables were quite apparent to me ( I brought over some 1 meter Silnote Audio balanced cables I purchased from Mark, at Silnote ). On another visit, I did bring over two self modified Yamaha amps for comparison, and found them to be quite competitive to the Benchmark, for neutrality. The Benchmark preamp is quite amazing, in it's neutrality. It surprised me. 
The Benchmark is an excellent amp.

The thing driving the interconnect cable is where the difficulty lies in supporting the standard. Its pretty easy to do in an amplifier- you can do it with a differential input, which can be done with an opamp easily enough. But to drive the balanced line so that neither the non-inverted phase or inverted phase references ground (the interconnect shield)- that's a bit of a trick. How its done in studio equipment is with a small output transformer that has no center tap. It has a simple secondary winding that has one side tied to pin 2 of the XLR and the other side of the winding tied to pin 3. Pin1 is tied to chassis and no connection to the transformer whatsoever. This is done to prevent ground loops but it also prevents the cable construction from influencing the sound. However for the latter its not enough to not reference ground- the circuit also has to be low impedance. For many years the standard was 600 ohms but these days is a bit higher: if your balanced source is going to support the standard, it should be able to drive 1000 ohms without bandwidth or distortion issues.

We patented a way to do this that is direct-coupled, which to my knowledge is the only other way to support the standard. Any system that employs dual out-of-phase single-ended outputs has to reference ground and so does not support the standard.


Clearly a passive simply cannot support the standard- and so the interconnect cable will impose a coloration, and quite often one that varies with volume. With many sources that employ an output coupling capacitor, it can cause a bass rolloff if the volume is set to anything less than full. This does not happen with all sources, but if it works out that way, the choice of passive volume control will have no effect!
My passive is single ended, and I am fine with it. Given everything you say, which is quite informative, still leaves me with 2 conclusions. The 1st is, balanced lines are useful, and necessary, when the lines are long, and / or there is an abundance of electrical, magnetic, or rf noise, contaminating the area ( which is truly likely in most circumstances ), balanced has a lower noise floor, resulting in a blacker background while listening. The 2nd is, there are very apparent sonic differences between cable brands, and as I mentioned, those models within the brands line. Balanced cables, as well as single ended cables, all sound different, and matching them to systems, can create a better synergy between the components, and sound shape the presentation, for the listener. Should this be the case, I do not know. But keep in mind.....I am one, who hears improvements, with an upgraded fuse ( another discussion ). I put a brick ( from your local garden / home improvement store, covered in a small towel ( towel to protect the equipment ), on top of an amp, preamp, transport, etc., and it changes the sound........anyway, thank you again, for your information and involvement with the discussion. You seem to be the only one, thus far. Enjoy, be well and stay safe. Always, MrD.
I have gotten a few private emails concerning the Luminous passive products, and passive, as a whole. I wanted to update this thread, as to create more interest, and truth, as to passive driven systems. There is no question, that extra gain can give you more " oomph ", but when listening to a piece of music, that has " oomph ", you begin to notice, with a good passive such as the Luminous, that there is finite information on the recordings, that can be lost, with extra gain. A longer signal path, cannot retain " what goes in = comes out ", with the most purity and clarity of the signal, and this is with a system that matches on all levels, source to amp. I would love to hear other stories here, as to those who have followed the passive path, understanding it has been discussed many times prior. There is a lot of repetition and repeat threads here, so nothing new. Enjoy, be well and stay safe. Thank you, MrD.
My passive is single ended, and I am fine with it. Given everything you say, which is quite informative, still leaves me with 2 conclusions. The 1st is, balanced lines are useful, and necessary, when the lines are long, and / or there is an abundance of electrical, magnetic, or rf noise, contaminating the area


Correct, the only time balanced becomes a noise advantage MrD is if the output and the input of all stages are true balanced circuits over very long cable runs, in very noisy environments like recording studios.

And here's the BS factor for balanced claims on sound quality increases.
 Many pieces of equipment today have balanced opamps grafted onto their inputs and outputs of single ended circuits!!!, so they can advertise they have a balanced input or outputs, they are only "pseudo balanced" because they use balanced opamps like these, 
https://www.ti.com/product/DRV134

 And then in the end nearly all power amps have single ended outputs as are speakers so the whole thing becomes a "furphy", for sound quility claims, your better off sound quality wise to stay single ended all the way, unless your in a recording studio with miles of cable doing all sorts of things.

Cheers George 
Balanced cables, as well as single ended cables, all sound different, and matching them to systems, can create a better synergy between the components, and sound shape the presentation, for the listener. Should this be the case, I do not know.
that has " oomph ", you begin to notice, with a good passive such as the Luminous, that there is finite information on the recordings, that can be lost, with extra gain. A longer signal path, cannot retain " what goes in = comes out ", with the most purity and clarity of the signal, and this is with a system that matches on all levels, source to amp.
@mrdecibel If your equipment doesn't support the balanced standard then you will be hearing differences between balanced cables just as you do with single ended cables. If your equipment supports the standard, then the differences between cables is vastly reduced! The benefit of balanced operation does not depend on the length of the cable- its there even if the cable is only six inches.


When you have a competent line stage that supports the balanced standard you will find that there is more 'oomph' not less (assuming that you mean more impact and more palpable images) on account of the simple fact that such a line section will not allow the interconnect cable to impose a sound.


The only way I know of to use a passive volume control and support the balanced standard at the same time involves the use of a transformer. The system we patented is the only other means I know of to support the standard and we've built versions that are strictly buffers with no gain. 


I have listened to passive units with transformers and find them to be round and colorful, meaning they are warm and the frequency extremes seem rolled of. They are not as detailed to me. Being familiar with pro gear and balanced lines, I still suggest, based on my listening, cable brands sound significantly different to me, whether they are single ended or balanced. I am not an engineer, and the reasons for this are likely many, as discussed here and elsewhete. I appreciate the feedback.
I have listened to passive units with transformers and find them to be round and colorful, meaning they are warm and the frequency extremes seem rolled of. They are not as detailed to me.
This is very true MrD of TVC passives (transformer volume controls) based volume controls.
But they "can" be liked in "some" problem systems that need some "band-aid" fix for other problems, eg harsh highs, or to warm (thicken) bass etc.

They color the sound just like any "audio based signal transformer" does, (EG: output transformers on tube amps, phono transformers, preamps etc etc), they fall short in in dynamics, detail, and frequency extreme, LF output impedances and distortions.
And the ones that are are wound with ratio taps so you can have some "extra gain" from them, they can ring like the proverbial "bell".

Cheers George
I have listened to passive units with transformers and find them to be round and colorful, meaning they are warm and the frequency extremes seem rolled of. They are not as detailed to me. Being familiar with pro gear and balanced lines, I still suggest, based on my listening, cable brands sound significantly different to me, whether they are single ended or balanced. I am not an engineer, and the reasons for this are likely many, as discussed here and elsewhete. I appreciate the feedback.
I'm not a fan of transformers either! But its worthy of note that many of the recordings you play probably have a transformer somewhere in the signal path; they can be quite transparent if of good quality. But I prefer to get them out of the signal path if I can.


One of these days you might try to listen to a setup that supports the balanced standard, if only so you can see what I am saying about how it eliminates cable colorations.
@atmasphere I know you are big on balanced, as this is so very obvious. I AM familiar with balanced systems, for a very long time. As I mentioned recently, I spent some time with the recent Benchmark gear, where we did a shootout with several brands of balanced cables, and they all showed various attributes, weaknesses, colorings if you will, and this included cables made by Benchmark. I am not sure why your insistence of " cables do not sound different ", when they are used in a balanced configuration. Several of us have heard these differences, and easily.......getting back to transformers for a moment. I feel, they are necessary in many instances.....but as a listener, I do not like them, in a home playback system, whenever possible. This is exactly why, you follow your path of OTL amplifiers, as your designs. Yes, it limits their ( OTLs ) use, but imo, transformers are band aids, that are needed in many areas. McIntosh makes fabulous output transformers, and continues to use them in their SS gear. However ( and I might get some backlash from some folks reading this ), my description above in my previous post, is exactly how I hear their amplifiers. Round, rolled off at the frequency extremes, colored, lacking in finite details, and sluggish and slower bass, than most ( why I do not use tube amps )However, I know hundreds and hundreds of listeners who use Mc gear and tube gear, and understand, and respect their decision to use it. Just not my cup of tea, as many, who do not like passive, or horns, etc. So, cables do sound different, whether single ended or balanced, to these ears. Always, MrD.
I am not sure why your insistence of " cables do not sound different ", when they are used in a balanced configuration. Several of us have heard these differences, and easily.......getting back to transformers for a moment. I feel, they are necessary in many instances.....but as a listener, I do not like them, in a home playback system, whenever possible. This is exactly why, you follow your path of OTL amplifiers, as your designs. Yes, it limits their ( OTLs ) use, but imo, transformers are band aids, that are needed in many areas. McIntosh makes fabulous output transformers, and continues to use them in their SS gear.

Apparently I've not made it clear: when the equipment supports the balanced standard, the cable differences are vastly reduced. Its readily apparent from the quote above that whatever product was driving the cables to the Benchmark, while perhaps being balanced it didn't actually support the standard. So you were hearing differences! The standard is also known as AES48. Here's a nice page from Rane that explains more about the standard:https://www.yumpu.com/en/document/read/46700632/rane-note-110-sound-system-interconnection-avw


Line transformers used in balanced line are vastly different than the transformers used at the output of a power amp! The smaller you make the audio transformer (and line transformers are pretty small) the wider the bandwidth that is possible. I would not be surprised to see a line transformer that could do 5Hz to 100KHz. Of course as you point out we are the OTL people, so we came up with a way to support the balanced standard in a **preamp** that not only has no output (line) transformer but is actually direct-coupled.



@atmasphere I will never claim to be as smart as you, but I am sure betting my hearing is as good as yours, and I will leave it at that. Although this thread was about passive vs active, you are making it about single ended, balanced, and balanced standard, AES48. I understand passive has it's limitations, and why you brought all of this up. I do not want to argue with you ( how I miss Almarq ). The entire system used during our cable evaluation was new Benchmark products, from the source to the amps, which I understand to be ( prove me wrong ), the standard AES48. And if I am wrong, so be it. I have been wrong before. So, given the " cable differences might be greatly reduced ", which is your wording, are you suggesting, that differences in cables, under these conditions, are NOT audible at all ? As far as transformers....I understand all that. I still do not like them, in applications that I am speaking. 
BTW...some of the cable brands we listened to were Audioquest, Cardas, Silnote, Kimber, Transparent, WyWires, Shunyata, Belden ( home made ), and the Benchmark cables. 
The entire system used during our cable evaluation was new Benchmark products, from the source to the amps, which I understand to be ( prove me wrong ), the standard AES48. And if I am wrong, so be it. I have been wrong before. So, given the " cable differences might be greatly reduced ", which is your wording, are you suggesting, that differences in cables, under these conditions, are NOT audible at all ?
There are very slight differences between the very best cables and the very worst- not enough to write home about; the balanced standard is very effective!


As best I can make out the Benchmark line drive unit does not support AES48. If a preamp has both balanced and single ended outputs that run at the same time, without a switch to go between the two, then its unlikely to support the standard.

This is because you can't operate both balanced and single ended off of the same output: they are mutually incompatible. What's happening with the Benchmark line drive (which is similar to their other units that make a balanced output) is that the balanced output references ground. That's a violation of the standard (and is quite common throughout high end audio). 

The following article is from the Benchmark website. If you read through it you will see that AES48 is not mentioned, although near the end of the article AES3 *is*; clearly John is familiar with the AES:

https://benchmarkmedia.com/blogs/application_notes/balanced-vs-unbalanced-analog-interfaces


It is also apparent from this article that John knows his stuff! I suspect he is aware that his line stages don't support AES48; otherwise he would mention that somewhere on his site as otherwise he makes all the right arguments supporting differential amplifiers and the like.


Now the argument has been made that if both outputs of the XLR connection reference ground, but the ground currents are identical, then they cancel. This is true but now the cancellation has a number value attached, because in the real world they won't/can't be identical. This is the same argument that some people mistakenly make for an output transformer (driving a balanced line) needing a center tap to reference it to ground. The reason this is not actually a practice is because the center tap can't be perfectly placed and so will degrade the CMRR performance. It also means that there will be ground currents in the cable, and further means that now the construction of the cable has become critical to its sound.


So I'm not doubting what you heard- I've experienced exactly the same thing. I think what's going on here is you were under the impression that the Benchmark line drives support AES48. That would explain about 95% of our exchanges on this thread!


BTW I miss Al too- he retired a few months back and has been far less active here ever since. I really appreciated his comments!
@atmasphere As I said, I am nowhere as smart as you, and if I am wrong, which seems to be the case here, I am wrong, and I thank you for all of the tech stuff you teach me, and many others here. I obviously made assumptions, and you know what that makes me......lol.....Question : Are there many high end home audio companies whose products offer balanced only, conform to the AES48 standard. Back in the day when I was an AES member, much equipment did conform ( pro and studio gear particularly ). Thanks again for the tutorial, as I always appreciate learning. Always, MrD.
Question : Are there many high end home audio companies whose products offer balanced only, conform to the AES48 standard.
I hate to say it but 'no'. Most of the balanced line preamplifier product I've seen that is balanced does not support the standard. Our preamps are some of the very few that do (and are also transformerless). But if you find a preamp that has an output transformer (like Backert Labs) then it can do it. 


IME this is why the use of balanced lines in high end audio is so subject to debate- very few people have heard them set up correctly so the results are really variable.
Late to this thread and way inferior on experience and technical knowledge. 

I think I lucked out with the EAR 868 which I purchased kind of randomly to sit between my balanced dac (holo audio may) and balanced amp (pass xa30.8). From what I've read about the 868, which is son of 912, I've lucked into a true balanced design. Sounds wonderful. Not neutral in a way that really synergies.

Ever listened to that one? 
I have never heard of anyone except for Atmasphere that claims that balanced cables sound the same. He says it must be to the AES 48 "standard". I guess all other gear then is not up to his "standard" except the gear he sells. However, I have seen several of his customers who also say that using his gear with the "perfect standard"....they hear all the same differences in balanced cables that everyone hears. Check out the big amp thread on the amp forum. He has used:.Audio Research, D’Agostino, Merrill, Luxman, Sim Audio, Parasound, Gryphon, etc. etc balanced preamps and amps and all balanced cables sound different on all these amps and preamps. He has owned over 50 amps and he gets the same result. Obviously, the only great preamp and amp combo that allows for perfect sound with any balanced cables is the Atmasphere gear....he he. Maybe the Atmasphere gear allows all balanced cables to sound identical.......however, with several of his customers saying otherwise.....well.....looks like imagination going wild. This whole conversation is invalid as hardly anyone has Atmasphere gear.......the only thing that matters is the sound. And all balanced cables sound different on virtually everything I have ever heard or most anyone. Use your brain, use your ears....decide for yourself.

Atmasphere......since you think that hardly any one has heard a "properly done balanced system".........why do you keep talking about it? Are you just trying to get people to buy your gear? So they will finally hear what balanced can do? Most people do not want your gear.....so, no matter what you say about cables......they are all going to hear all the differences in cables that are very obvious to any who listen. So it is silly to keep saying that balanced cables have no sound since everyone but you hears something different.....I exaggerate.....maybe a couple of people agree with you.....he he.

By the way, I use a modified DAC that has balanced out only and is not referenced to ground and my balanced only amp is done the same way.....DAC driving amp directly.....both done to AES 48 standard.......still, every cable, every direction of cable, etc. etc. sounds different....the same difference I hear when AES 48 is not totally followed.
@atmasphere 
Hi, 
"As best I can make out the Benchmark line drive unit does not support AES48.
If a preamp has both balanced and single ended outputs that run at the same time, without a switch to go between the two, then its unlikely to support the standard." 

Now this statement tickled my interest, even for the *unlikely* mentioned, rather than using a NOT. 

Why? 
I'm using all fully balanced Levinson gear, DAC, CDP, and Pre-amp (into PassLabs amp). 

Both, single-ended and balanced are active all the way through, as explained (in the manuals?) single-ended is 'simply' a summed up XLR/AES48, even for the digital DAC36 etc. inputs XLR, RCA, and then some. 

So, this now 'could' mean that AES48 is not properly 'implemented' - really?

I find this difficult to believe. I do. 
M. 🇿🇦 
Not seeing how balanced negates the transfer function of the cable unless you are assuming lower source and load impedance. The noise rejection is obvious of course.
So, this now 'could' mean that AES48 is not properly 'implemented' - really?
@justmetoo   It would not be the first time I've been wrong, not by a long shot!


To meet AES48 the output of the source (preamp, in this case) does not reference ground. In order to see if your equipment supports the standard, a simple test can be conducted.


You'll need an amp with a single-ended input and a cable that goes from XLR at the preamp end to the RCA of the amp. Its important for this test that pin 3 of the XLR on the cable not be connected to anything, so pin 2 is signal and pin 1 is ground. 


Plug it all in and run the preamp and amp. Do you have a buzz? If no, the standard isn't supported. The reason there is no buzz is because the output of the XLR is referencing ground- so there are are return currents passed through the shield of the cable to complete the circuit. A circuit that supports the standard will not have a path through ground to complete the circuit- and so it will buzz unless pin 3 is tied to ground or some conversion from balanced to single-ended is made (for example, through an output transformer).



.since you think that hardly any one has heard a "properly done balanced system".........why do you keep talking about it? Are you just trying to get people to buy your gear? So they will finally hear what balanced can do? Most people do not want your gear.....so, no matter what you say about cables......they are all going to hear all the differences in cables that are very obvious to any who listen. So it is silly to keep saying that balanced cables have no sound since everyone but you hears something different.....I exaggerate.....maybe a couple of people agree with you.....he he.
Still not seeing how this negates the transfer function of the cable.
One aspect of the balanced line standard is in fact that it is low impedance- there is in essence a termination standard, whereas with single-ended there is not. The low impedance aspect is as important as the aspect of not referencing ground- it swamps cable 'transfer function' (which is the capacitance and inductance of the cable).


And of course *everyone* has heard balanced cables set up properly- they are in most recordings. Mercury used to park their recording truck behind Northrup Auditorium in Minneapolis to record the Minneapolis Symphony. The mic cables had to run nearly 200 feet. I experience this when I was playing in the St. Paul Civic Symphony back in the early 1970s. One of our performances was being recorded and I saw the mics hanging over the orchestra when we were warming up. The cables went into the cloud ceiling then down to a booth off to the side of the auditorium. I investigated and got to hear the mic feed over headphones. That and prior work in the studio is why I know this system works. Its why we made the first balanced line products for home stereo use. In the 1950s when hifi was getting going, the cost of transformers was not cheap and consumer equipment was. The RCA connector was originally used in televisions between the tuner and IF amplifiers; it was cheap and wide bandwidth; that is the main reason they are in use today. But high end audio is all about how far you can push it to get your system to sound like music instead of electronics- the balanced line system is a nice step in that direction as it removes cable artifact.


Many recording engineers of course have heard balanced cables set up correctly- which is why if you talk to them they will tell you cables don't make a difference. Audiophiles often assume they are talking about single-ended cables; audio engineers often assume audiophiles are talking about balanced cables. So there appears a sort of disconnect that makes it seem to audiophiles as if engineers don't have good ears or something. Its not the case- just apples and oranges.


I talk about 'properly done balanced system' because once you hear it there is no going back. There are balanced cables made today that cost over $1000/foot; if you subscribe to the Veblen Effect (consciously or unconsciously) you might be convinced that cables costing this much are some of the best made anywhere. One of the advantages of balanced operation is you can run long runs, allowing you to place your amps as close to the speakers as you can to minimize the effect of the speaker cables. Imagine a 30 foot run of cable that's $1000/foot; now imagine a system that negates cable artifacts allowing you to run the same length with inexpensive cables and no audible difference. In case anyone has a problem working this out, setting up a balanced line system that works properly is a lot cheaper, and you don't have to think about a cable investment loosing its value in an incredibly short time...


Thank you atmasphere, that is what I assumed the answer was.

One aspect of the balanced line standard is in fact that it is low impedance- there is in essence a termination standard, whereas with single-ended there is not. The low impedance aspect is as important as the aspect of not referencing ground- it swamps cable 'transfer function' (which is the capacitance and inductance of the cable).

@atmasphere Ralph, great story. I am sure in my past life I had many instances of using and listening to a true balanced system. So, what can we all do, to get this type of balanced system into out listening rooms ? 
@mrdecibel Insist that if there is a balanced connection, that it support AES48 in all aspects.



Ralph,
I have had 100% true/dif balanced systems for decades (typically with a balanced preamp), but find it super easy to hear differences in XLR cables

My current set up is a Oppo 105 direct to a dual mono balanced only amp, and I can still differentiate differences in different XLR companies
Please, enlighten me
I have had 100% true/dif balanced systems for decades (typically with a balanced preamp), but find it super easy to hear differences in XLR cables
Try setting the input impedance to 2000 ohms in your amp. I doubt that Oppo would drive that, but if it does, I'll think you'll find those differences went away. The impedance aspect of the balanced line system is as important as the fact that it ignores ground (which I think the Oppo does not).


Its pretty obvious why the high end audio industry does not embrace AES48. Driving a 2000 ohm load (or less, the old standard was 600 ohms) is hard. Also, having an driving circuit (like at the output of a CD player) that ignores ground is hard.
I find the whole debate in this thread a bit specious. Passives don‘t do balanced and yet: I‘d take a Wavac ATT-s plus EC300b over any balanced amp provided you got sufficiently efficient speakers. Prior to the Wavac I was running a Graaf combo of 13.5B2 and GM20 and on digital it was no match, conversely on analogue the Pod is more challenged. Good cables disappear, and that applies to balanced and single-ended.