In or out?

October 17, 2021
 by Paul McGowan

Over on the PS Audio YouTube channel, there’s a spirited debate over terminology. In a balanced signal, are the two halves out of polarity or out of phase?

I suppose the fact viewers are in a heated discussion over such semantic differences is a good thing. Or maybe it means folks have more time on their hands than I imagine.

The answer is both are accurate though one is more technically correct than the other.

Phase generally refers to a change in time while polarity is absolute.

In balanced audio, we have two conductors with signals, each 180˚ out of phase with the other. As one signal is rising its mate is falling. Sum the two signals together and they should perfectly cancel each other out and we get zero signal. We use this difference between the two to our advantage. If our balanced signal is fed into a balanced input, then only the difference between the two signals is amplified (and they are 180˚ different from each other). Any signal common to both signals is rejected (called common-mode rejection). Hum and other noises leaking into the balanced cable are eliminated.

So here’s the rub. If we say the two signals are of opposite polarity to each other we communicate correctly what the signals are that make up a balanced cable. It is also accurate to say the two signals of opposite polarity are out of phase with each other.

So, both are correct though one way of expressing it makes for fewer arguments among us nerds.

The trick about communicating is to make sure you’re speaking clearly to the audience and that they understand.

Or, find an audience with less free time on their hands to argue about such trivia.

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53 comments on “In or out?”

    1. except that the ‘simple’ single ended circuit amplifies the negative half of a wave form differently than the positive half. But, of course, a single ended circuit must be class A. Certainly the output of Goldmund amps is not single ended.

        1. I already asked Nelson if I’m correct. He said I am but he likes what single ended sounds like. He’s one of the few people I’ll accept that from since he’s one of the few people who knows about single ended assymmetry .

      1. I have a large pile of Miele kitchen appliances waiting to installed that cost about the same as a 3m pair of Dragon speaker cables. This whole audio thing has gone off into territory with which I am not familiar, or interested. Why isn’t the T20 qualifier between Oman and Papua New Guinea being televised? Starts in an hour. It’ll surely be a thriller.

          1. It was a home game for Oman in Muscat. Stunning ground. Broadcast on Sky. Bit of a cracker, Oman won by 10 wickets. Scotland v Bangladesh next.

        1. I learned the term ‘boffin’ watching “Top Gear” on BBC America. I miss James, Jeremy, and Richard. “Old school and the better for it.”

  1. **Off Topic**
    ‘Facebook’ the new tobacco.
    (Profits over the safety of your children)
    I knew that there was a good reason why I have no interest in it.

    1. If all Facebook users came to the decision that this supposed social media outlet has helped to destroy us for the pleasure and profit of one disgusting human being, the world would be a far better place.

  2. Forgive me for mentioning this because it’s slightly off topic but this discussion reminds me that much of our prized tube gear creates a signal out of polarity and often benefits from two devices that re-reverses it back to correct before sending it to speakers. Or speakers can be connected in reverse (pos/neg) to make up for a single device. When needed I reverse polarity in player software before sending it to a reversing tube preamp. At any rate it’s a good idea to be aware of which of your nice tube gear does that. (I said “polarity” not “phase” anyway.) We could have another discussion about how running it backwards affects the audio.

    1. Yes, this is exactly what I have to do because my c-j GAT S2 preamp inverts phase ( polarity or any other way you want to say it ). I switch the leads of my speaker cables when I connect them to the speakers ( black to red and red to black ) to restore original phase or polarity. My old c-j P16 preamp did the same thing. I wonder if all c-j preamps are phase inverting?

      1. Tony,
        Why would they (c-j) do that and does it really matter. Did it sound better when connected to original polarity or was it just for neatness and symmetry?

        I used to invert the phase of my subs so they were working with my main speakers rather than against them. There is a switch on the sub to enable this and though in my head it seemed ‘untidy’ if you know what I mean, it was audibly obvious which way was correct.

        1. I am not enough of a tube circuit designer to be able to say why c-j builds preamps that invert phase. I do know that c-j’s basic philosophy is that you get the best sound when you build simple circuits with the highest quality components. My guess is that rather than add a component to invert the phase they simply tell customers to flip the speaker cable leads.

          I can use my my PS Audio DS DAC to invert phase when I play SACD’s or CD’s. I cannot invert phase on my vinyl rig. On some music when I flip the phase the soundstage appears to move back two or three feet. But, this does not happen all the time.

          I have an REL subwoofer in my video system and it too has a phase inverting switch that makes a noticeable difference when iit is flipped as you said above.

    2. In the world of psychoacoustics there are three phenomena that are I’ll defined namely backward, simultaneous and forward masking. Of the three backward masking is the most ill defined. It’s all about timing of the signals as to how they exist on the temporal spectrum.
      And you think audiophiles have problems!
      The only way to accept a concept is to be comfy with the way you define it, stick ones head in the sand and …..

  3. “Or, find an audience with less free time on their hands to argue about such trivia.”

    When I first discovered this site I was surprised at the level and degree of detail that people would discuss things. Now I’m involved in it. What happened?

    To be more serious for a moment, the minutiae matter. An improvement, no matter how small, is still an improvement and should be cherished.

    I’m all for keeping it clean and simple but sometimes/frequently that’s just not possible, audio is a complicated business.

    Off topic but still audio. I was listening to a new CD last night having previously read a review. The reviewer noted that the first few tracks were recorded at a lower level than he liked. Well, my first thought was that’s what the volume control is for, but that’s another story. It just made me wonder that had he not pointed it out, would I have noticed it? In all honesty, probably not, the difference wasn’t that great, but having read the review I was listening for it. My point is that while critical listening is essential for evaluation it’s so much nicer just to listen for enjoyment.

    1. So when is this listening for pleasure going to happen the way it was meant to be? It’s a wonderful feeling allowing yourself to be in the moment, put aside your critical nature and let music enrich your soul?

  4. So phase has a time related component. No argument. Then it’s possible that in a balanced set up a mismatch of +/- signal lengths or circuit lengths could result in theoretical distortion versus single ended? (This of course is ignoring the common mode rejection advantage)

    What’s the best way to ‘marry’ the two topologies? A transformer or an adaptor? If an adaptor is used and going from balanced to rca should that adapter be at the source and then use a single ended cable, or at the receiving end and use a balanced cable. (Assume the same model and brand of wire)

  5. Here is some food for thought.
    Take a cheep single ended tube stereo amp, like the Tube Cube 7 tube amp, and see if you can pull this trick off with it.
    But, I must worn all of you, that you will need two of these, if you want to do this in stereo.
    Because this trick, will convert a single ended stereo amp of any kind, in to a mono block.
    The only thing that you’ll need here, is a CD player or a preamp that has a pare of balanced outputs.
    But also, you will have to have some knaallage of cemple wiring. If you have all these things then it will be a singe to pull this trick off.
    With the XLR cable that will be supplying you the balanced signal, the output end of that cable, needs to be terminated with a pare of RCA plugs.
    Plug that in to the inputs of the Tube Cube 7.
    But on the outputs of the Tube Cube 7, each output transformer, has 4 connections on them.
    They are in this order.
    Ground, 4ohms, 8ohms, and 16ohms.
    From right to left.
    The way you will need to connect your speaker to this amp in order for this trick to work, you’ll have to do it this way.
    The black wire, to ground on the first output transformer.
    But sense I like a little more power then what you would usually get from a low powered amp like the Tube Cube 7, I will use the 16ohm tap on the second output transformer.
    Some people will tell you that, you will need to connect the ground of the second output transformer to one of the hot taps on the first output transformer.
    But I will tell you truthfully, that I’ve never made a mistake that didn’t teach me some kind of a lesson.
    Don’t do that because you’ll blow the hole amp up.
    Including its tubes.
    Both transformers will see a load, at the same time.
    But anyhow, this is the reason why I’m gonna use the 16ohm tap on the second output transformer.
    The 16ohm tap, has the most amount of voltage and currant coming off of it.
    And both output transformers are internally grounded by default.
    This is why you don’t merge the ground wire on the second output transformer to one of the hot wires on the first output transformer.
    But once you got your speaker connected to the amp, and you have both of the unbalanced inputs of the amp being fed by the XLR cable that you converted the output side of to RCA, you just not only converted that amp to a mono block, where that amp started out as single ended, is now push/pull.
    And also, you’re now also, getting grater then 14 watts out of that amp, in to an 8ohm load.
    But if you want this to happen in stereo, then you’ll need another Tube Cube 7 tube amp.
    Just repeat the steps above, and you got it!

  6. In a debate about „the meaning of life“ this would just be the side discussion, if it shouldn’t better be expressed as „the tenor of life“ for those who don’t have too much to say about the root topic. It happens all the time, especially in social media.

  7. Guys
    I’m happy! Well………
    Just got a new integrated amplifier
    Class D 150 into 8 and 250 into 4 ohms
    Just trashed my Class D separates not because of the wire maze , but because of breakdowns and poor chip function!
    The new gear is so “dynamic” and provides a great sound stage.

    I get a big kick out of those professing
    How the sound comes from behind the speakers while they are busy pasting treatment on the walls especially behind the listener sweet spot.
    Hey I got it – how about a tens unit worn while listening to jolt the audiophile into place if one moves off the sweet spot!!!
    All I can say is that in my cave I have a clear sharp dynamic and enjoyable listening experience! By the way my back wall is covered with pictures in glass frames as are the side walls! Some of the photos were taken with a 6×6, some 645, some 35mm full frame and cropped and they all get along!

    1. Congrats Larry!
      It’s so much fun to have a new amp, that improves the overall sound of your rig, to play with.
      The pictures on your walls all get along because they don’t discuss the finer points of lighting, grain, exposure & focus 😀

      1. True about the photos. However camera clubs are worse than anything. People criticize a shadow! But this new amplifier truly redefined listening. I can hear the exact place the instrument is in the orchestra. Very clear and enjoyable .
        And this comes at a time when I have down sized living space a lot-it was a good accident that all this happened!

  8. I still wonder why people sometimes report that a single-ended interconnect cable sounds better than a balanced version of the same cable, even when their systems will accept both single-ended and balanced. Perhaps it’s because so many components offer XLR inputs and outputs when their circuitry is not truly balanced, or it could be that XLR connectors are bulkier than single-ended connectors and add distortion. I have not compared single-ended cables with balanced cables in my system, just assuming from the start that balanced is the way to go, despite their added expense.

    1. Joseph LG – I have compared single ended and balanced on my system. The biggest difference I could hear was that of “clarity.” But, then again. I was warned by a technician representing the manufacturer of my equipment, that balanced circuitry must be done perfectly (warning that certain manufacturers tend to cut corners) and in that case, single ended may end up sounding better.

  9. So, as an old friend of mine often said, “Not only, but also.”

    He had once cited a source of this quote, but it is lost to my frequently alluded to aging slushware in the depths of time-space. The quote made it into the relatively robust “Weird Sierra Files”, but the metadata did not. He shuffled off this mortal coil years ago, so I cannot ask him. A quick search via Google came up empty.

    1. Confused Steven,

      I can’t help with the source of the quote but the first thing I think of when I see or hear “Not only, but also” is the BBC comedy sketch show of the same name starring Peter Cook and Dudley Moore.
      Hopefully the link will provide more information.

      https://en.m.wikipedia.org/wiki/Not_Only…_But_Also

      Mmm, it doesn’t seem to like that link. It worked okay on my email. Suggest try typing it in or search wiki.

      1. Found it. Thank you, Richtea. Received wisdom is always appreciated. My old friend was an aficionado of British humor/humour, so a good chance that this was where he picked up the phrase.

  10. Rules are the lay person’s analog to scientific theories. They represent a summary of experiences to date. Of course they are going to change with more data.

    Toe-in is really changing the diffraction patterns you hear, both direct and reflected. I am really sensitive to this, and usually choose a seat where the cellos and/or basses are pointed at me because their toe-in distortion effect is worse than even sharp edged rectangular speaker baffles.

  11. Paul, I hereby charge you with creating a monster! You really took Pavlov’s experiment learned in Psych 101 to heart. To wit, the commenters don’t seem to change much.

    Phase and polarity are one of the least trivial subjects discussed in this venue. There are practical reasons for knowing about them. We are often asked to set them in a device without really understanding the impact.

    As a recovering Catholic, I feel compelled to confess: I find it alarming reading postings and comments and ending up more confused at the end than I was at the beginning. I am sure that was not the venue’s original intent.

    It must be that my intellect doesn’t measure up. Are there Cliff Notes for Dummies anywhere? I think I will switch to other fountains of knowledge. It is easier to Google and get clear and more definitive on a subject a lot faster.

    Silence from thousands of subscribers must mean they phased out a long time ago. Did their supply of weed run out? My supply of benzos is running low and that is not trivial.

      1. Ouch, that hit home. Memories came flooding back, of disclosures that were eerily the same from one week to the next. I always wondered how the good Father never tired of the sameness. Or maybe he did, and that was the price he paid for my temporary existential relief.

        Well, I have him to thank for one of my passions. When Castro took over the Catholic schools and kicked out the clergy, he bequeathed me his record player and classical record collection. That was my audiophile beginning.

        Christ, that was 60 years ago. Now I feel old and confused.

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