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Balanced v Unbalanced

Discussion in 'audio' started by SteveG, Apr 30, 2019.

  1. March Audio

    March Audio Trade: March Audio

    As I said earlier anything can be done badly, SE isn't immune so this is a non point.
     
  2. March Audio

    March Audio Trade: March Audio

    Rolls has its own large calibration lab(s) which I also worked in. I have also worked representing Keysight(formerly Agilent and Hewlett Packard) on their entire equipment range from DVMs to spec ans to audio testers. Of course there is instrumentation that is single ended but anything involved with amplification or signal conditioning (the specifically relevant bit) invariably used balanced for the reasons discussed.

    It's more robust (signal wise) and avoids gnd loops.
     
    CJ14 likes this.
  3. March Audio

    March Audio Trade: March Audio

    And this is the point. The idea that some have that it is lower quality is unfounded. If it were pretty much most of your recordings have already been ruined by the use of balanced in studios.
     
    misterdog likes this.
  4. March Audio

    March Audio Trade: March Audio

    There is no need to defend unbalanced, its not being attacked.

    Actually I have said pretty much exactly that further up the thread. I said balanced is, all things being equal, no better or worse sounding than SE. However it does have better noise rejection cmr /signal levels and avoids gnd loops.


    I wholeheartedly agree with you on the amount of foo in domestic hifi and it annoys me immensely. The amount of total horse shit technically ignorant punters (no disrespect intended) are sold in this hobby beggars belief.
     
  5. TonyScarlett

    TonyScarlett pfm Member

    I don't think anyone one on this thread is arguing that balanced is lower quality, just that it adds unnecessary complication & therefore cost to solve a problem that simply doesn't exist for 99% of domestic users.
     
  6. March Audio

    March Audio Trade: March Audio

    It's been mentioned several times and it often comes up elsewhere. This idea that it's somehow complex or significantly more expensive isn't true. It's very standard circuit topology and the component cost is trivial.

    I would certainly put it way further up the list of things to consider compared to other issues audiophiles get concerned about such as cables. There are very few people on this forum that might have actually taken a look and measured what noise is going on in a (their) system, although I now fully expect someone to chip and say they have seen nothing. ;)
     
  7. John Phillips

    John Phillips pfm Member

    AIUI, modern DAC chips usually have balanced outputs carrying differential signals as you describe, converted by an op-amp or equivalent to single-ended signal for an RCA connection, when required.

    Assuming the DAC chip outputs (in a DAC or CD player) are preserved and sent to an XLR balanced output then moving that differential to single-ended conversion from the DAC end to the active loudspeaker (or to the amplifier if that's where the DAC/CD player is connected) seems to me to be the minimum intervention approach in the signal path.

    This also gains the noise rejection properties of the balanced-impedance connection (probably not needed outside the studio but it can't hurt here).

    The above is why I would use the XLR connection if I were in the OP's position. But I would still not expect a difference as I would expect both signal paths to be good. Maybe the OP will contradict me in practice, though.
    If you are talking of a single-ended signal from the AV amplifier across a balanced connection to an active loudspeaker then I think you are referring to figures 1, 2, 3 and 4b here. Figure 4a without the resistor is imbalanced and does not get the full noise rejection properties of a balanced connection. If you know the AV amp's output impedance you know the resistance to use.
     
  8. Dowser

    Dowser Learning to bodge again..

    Thanks both - they’re Camac connectors Tony. Honestly, I didn’t think mine had them as an SE option, but browsing pictures shows they all seem to have them...so I must be blind!
     
  9. Arkless Electronics

    Arkless Electronics Trade: Amp design and repairs.

    Not sure if I'm misunderstanding your post here martin... but the classic single op amp balanced input circuitry does indeed have a big problem with this as you say but it is completely solved (at the expense of greater complication) by the 3 op amp instrumentation amplifier.
     
  10. martin clark

    martin clark pinko bodger

    You're right, Jez: I'd conflated the two.
    It was late...
     
  11. SteveG

    SteveG pfm Member

    The system is set-up properly now and before I tried to do any balanced v unbalanced listening test the first thing I wanted to check was the sound level listening to the same bit of music at the same amplifier setting, now I've located my sound meter.

    The difference is huge - at a very moderate listening level (35 on the amp) which equated to db levels at my listening position in the low 70's (maxxing at 72db) on the unbalanced connection it was instead the high 70's (maxxing at 78db) using the unbalanced connection. So not easy to do a A v B comparison!
     
  12. Fretbuzz

    Fretbuzz pfm Member

    Had an 840c. Nice unit. It was definitely louder with the balanced vs unbalanced option (going in to matching 840A mkII amp), but don't think there was much difference at all when level-matched.

    I started off using the 24/384 upsampling but found I actually preferred the 'pass through' (no upsampling) mode for CDs at least. Didn't use for streaming. Worth playing around with either way.

    Nice malt choice!
     
  13. G T Audio

    G T Audio Trade: Distributor and Manufacturer

    About 25 years ago I bought a new Mark Levinson 26S pre-amp to go with a pair of ML2 monoblocks. At that time this was supposed to be the best you could buy solid state wise. I upgraded from a pair of ML6a mono pre-amps to the 26S as the sound was more open, spacious and realistic. The 26S came with an onboard MC phono stage and a line stage, both single ended. I was told by the Mark Levinson agent the way to improve the performance for better sound was to upgrade the line stage with the balanced line input board and move the phono stage out of the chassis (to make way for the very large balanced line board) and into the separate ML 25 case. I went ahead with this upgrade, assuming that ML knew what they were talking about. Everything was done and listening tests were made both before and after the upgrade.

    Unfortunately, the upgrade was a massive disappointment. Not only did the phono stage sound worse than when it was inside the 26S case, but the balanced line stage board didn't sound as good as the original single-ended board either. I ran a proper balanced connection from the DAC (XLR to XLR) into the 26S. In the end, I just sold the whole lot on as I just couldn't be bothered to convert it all back again, plus the sound was just awful compared to what it was before. Read into this what you like but to me, the extra complexity of the balanced circuits plus all the extra connections had their effect which made things significantly worse.
     
  14. sq225917

    sq225917 situation engineer

    Ha ha, bodger... whoda thunk.
     
  15. DimitryZ

    DimitryZ pfm Member

    It seems that ML equipment was SE inside and the input board was just a complex add-on. My experience, with natively balanced circuitry inside preamp and amps (Emotiva) has been very positive.
     
  16. SteveG

    SteveG pfm Member

    As it happens I've now got a 2nd source with balanced outputs - a DAC this time. It's also from Cambridge Audio and, like the CD players, is much, much louder on the balanced outputs. Is that a general trait with balanced or just their implementation of it?

    It's not looking like I'll be using the balanced option going forward anyway - I'm now using the Cambridge Audio CD player just as a transport because I prefer the sound of the Simaudio Moon Dac to its internal one, and also prefer that DAC to the Cambridge Audio One which is going into a different system with an amp that doesn't have balanced inputs.

    So basically I think the only thing I've definitely proved is that the Cambridge Audio implementation of balanced outputs is very loud! When I did try and balance out the sound levels I can't say I really noticed an appreciable difference between balanced and unbalanced but really didn't do much comparative listening as the difference in volume levels made it a pain in the backside to do properly.
     
    Last edited: May 17, 2019
  17. I.D.C.

    I.D.C. pfm Member

    I have JPS XLR Speaker cable have no idea if it's good or bad. When buying my gear I rely on the dealer I bought all my equipment from to keep me right. The whole system to me sounds very good. Does anyone know if XLR SPEAKER cable is good.
     
  18. sq225917

    sq225917 situation engineer

    Balanced is usually louder as it swings more voltage.
     
  19. Fourlegs

    Fourlegs Trade: WAVE High Fidelity digital cables

    Well, err, it is a fundamental part of balanced circuitry that the balanced is twice the voltage of unbalanced.
     
  20. sq225917

    sq225917 situation engineer

    There's not much gets past you, is there.

    Yes it's a 3db increase in power, and a 10db increase is generally agreed to sound twice as loud.

    My point was you need to know the reference level.
     
    TheDecameron and Wilson like this.

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