Balanced Cable Discussion


#41

Paul MCGowan is definitely a smart guy. Another such guy is Ted Smith, who contracts with PS Audio - Ted Smith “oozes brilliance.” He explains things well, and will take the time to answer tech specific questions from the forum members.


#42

Thanks for the tip. I always want to learn on this great musical journey.


#43

@Torq Am I understanding this correctly? In order to be 100% true balanced one would have to have each piece of gear in the chain be (true balanced)? Music Source Balanced>Dac>Amp . All with True balanced cable. I believe the Lcd4s are already true balanced.

All in all what would be an example of that someone might have already?


#44

The purpose of balanced circuitry is to combat noise added (primarily) over interconnects. It is especially common for low voltage signals such as those generated by microphones and thus most mic cables are balanced. The important thing to know about a balanced circuit is that there are two signals of different polarity passed (for each channel). Before using the signal the two channels are subtracted from each other and noise added to the connectors will have been added equally and will be removed by this subtraction. As far as I know this is the purpose of balanced circuits and cables.

This would seem to mean that because headphones are passive (in terms of electronics) using balanced cables don’t bring the benefit of this common mode noise cancelation. The only reason to use a balanced cable for headphones would be the ability to plug it into the balanced output of an amplifier. If the amplifier is not truly balanced then even this benefit would be negated.

I do have balanced cables but only so that I can use the balanced output of amps. There is no sonic benefit in using a balanced headphone cable apart from the balanced output being cleaner and often have more power available.


#45

There are significant differences in what it means to be “balanced” for a source or amp, for transducers (headphones and speakers), and for connections to headphones.

For sources, source-to-amp-connections and the internals of amplifiers, “balanced” (technically “balanced differential”) means that you have two signals, in opposite phase (i.e. one positive, one negative) that exactly mirror each other. This has two effects:

  1. Noise/interference induced in one phase will be exactly mired in the other phase, thereby cancelling it out. This is important when dealing with very low level signals (phono cartridges, microphones) and for long cable runs.

  2. Effectively you have double the voltage swing for a given signal, since instead of it being a positive/ground (ideally 0V) reference, it’s a positive/negative. Or, in other words, twice as much signal to work with.

For an amplifier to be balanced/differential it, therefore, must have twice as many stages of amplification … instead of one for each channel it now needs one for each phase of each channel. And you’ll get both twice the power, as well as twice the noise (same noise per channel per phase, but now with double the number of phases)!

A “fully” balanced implementation to this point, would need differential outputs from the source (e.g. a DAC). And then balanced inputs into the amplifier, which would internally have two amplifier circuits per channel (one for each phase).

An amplifier can take a single ended-input and phase-split it to drive actual internal balanced-differential circuitry. Similarly it can take a balanced-differential input and sum the phases to deliver a single-ended output.

So, ideally, to this point you have a balanced output DAC, a balanced amplifier (using it’s balanced inputs AND output).

Next comes headphones … and “balanced” here is a rather poor description!

A headphone (or a pair of speakers) is really only “balanced” in the sense that it is fed completely separate signals for each channel. That means no shared grounds. A 1/4" TRS jack only has three connections, so it has to share the ground for each driver. Sharing the ground results in crosstalk between left and right channels (readily measurable).

Balanced-drive for a headphone first keeps the grounds separate, so it requires a 4-pin connection on the amplifier end AND a 4-conductor cable (minimum) with separate +/G or +/- connections (two conductors per driver to do this). And this is where you get the biggest benefit from a “balanced” headphone amplifier - it is much more important than anything up-stream being balanced!

ANY headphone that has separate connections to each ear-pieces and removable cables can be driven in balanced mode simply by using an appropriate cable. And, of course, this means that any headphone that has internal connections and/or a 3-pin connection on one side of the headphone cannot easily (or possibly at all) be driven in balanced form.

The second benefit to balanced-drive on a headphone is that if the amplifier is a balanced-differential design, then it’s balanced output should have double the power of it’s single-ended output - which is useful for headroom, keeping the amplifier components in their sweet-spot, and so on.


But, yes, a “fully balanced” setup, would have a balanced-differential source output (e.g. from a DAC with separate DAC chips/converters for each channel and or each channel/phase), feeding a balanced-differential amplifier and using a balanced cable to the headphone.


The LCD-4 has separate feeds for each ear cup. Audeze selll both single-ended (1/4" TRS) and balanced-cables (4-pin XLR) cables for it, as do many third-parties. If you use a balanced cable, from a balanced amplifier output, then you have the most important part covered and your headphones will be on balanced drive.


#46

The balanced output will almost always have twice the noise vs. the single-ended output.

The bigger, and more beneficial, difference is in keeping the signals to each driver completely separate which reduces crosstalk - and that improves resolution, imaging and micro-dynamics. It’s measurable too.

While balanced amplifiers tend to be twice as power via their balanced outputs than their single-ended outputs, nothing stops a designer making a similarly powerful single-ended amplifier and not doing the balanced bit at all.


#47

Paul McGowan in video talks about true balanced cables instead of balanced. As I think I understand it all in the chain must be balanced to have it balanced. He also claims better sound.

II’m hing all the smart guys out there can help me get it. I’m not sure I’m not. the brightest crayon in the box.


#48

Yes but. With noisy setups the reduction in noise has an enormous impact–I perceive that drivers that lose detail due to random noise on single-ended suddenly sound better because they no longer have to process irrelevant signals. Not all drivers are affected equally, and not all cables are created equal either.


#49

“True balanced” is not a technical term or reference.

“Balanced” in audio means each channel has two signal lines, driven in opposite phase. That’s it.

Anything beyond that is implementation specific.

Other terms you’ll see are things like “fully balanced” which might refer to a setup that is balanced end-to-end (from source to transducer), and “balanced-differential” (see above).

Way too much of being balanced is made in home-audio circles. The only things it does for sure is roughly double the cost of something vs. what a single-ended version of the same thing would take to build, and generally double the measure noise from source and amplifier (it’ll generally be well below audible thresholds, but it still doubles).


#50

So, if I want to upgrade my MD HD58x ‘phones to a balanced cable, how much should I expect to spend? Obviously (to me anyway) is that I don’t want to spend more than the headphones cost on cables. And I still need to get my DAC/amp stack before I spring for the cables. Just trying to set a budgetary number.

The little ES100 has a 2.5mm “balanced” output so I’m thinking I could experiment with it until I get a more robust tabletop system.

Thoughts?


#51

My HD-600 balanced quest began and ended with this very cheap 2.5mm TRRS (currently $22) eBay cable:

It reduced the background noise so much that I heard the limits of the drivers and saw no need to go further with $300 headphones.


#52

What kind of noise were you getting with your old cable? I’m not sure how a balanced cable for headphones would reduce noise.


#53

Please see the article on balanced headphones here (e.g., crosstalk distortion through the ground wire):

With my factory Sennheiser cable I always heard high range hiss/scratchy sounds. The HD-600s made my ears ring within 1 hour.

Balanced has independent ground wires and “a blacker background.” The hiss and ringing went away and I suddenly started to enjoy the HD-600s for 2-3 hour sessions. No more hiss or pain.

You ears and mileage may vary, but this happened with literally the cheapest balanced cable I could find online (via a FiiO Q5 amp/DAC). I’ve paid more for balanced cables and had little or no improvement with other headphones. Balanced seems particularly important for the 600 series.


#54

That article talks about a balanced system. I agree that a balanced source + amp has sonic benefits (including lower noise), but I don’t see how you would get those benefits from using a balanced headphone cable with a single ended source / amp.


#55

The whole system does indeed matter and there is no logical value to just using a balanced cable alone. I use them with balanced amps:

  • Massdrop THX AAA 789
  • Loxjie P20
  • FiiO Q5

#56

I grabbed a Yinyoo balanced cable for my Chinese IEMs from Amazon:

It’s currently $20, but was $16 when I got it. So far I’ve tried it with my KZ AS10s. It may slightly thicken the low to mid range and mellow out the treble, but I need to do more testing. Regardless of its audio properties, the cable is very soft and comfortable around the ears. It’s also compatible with my balanced connectors.


#57

I need a new cable for my CA Andromedas… the litz cables are seperating at the MMCX connector, I may try and shrink wrap it but not sure how well it will do in keeping them from breaking.


#58

Those are the cables I have been using for most of my IEMs. I have mmcx and 2-pin connectors.


#59

Yinyoo do great cables at a reasonable cost. I have several and they have served me very well so far.


#60

I picked up a couple of the Yinyoo 2.5mm TRRS cables to play with all these cheap IEMs I’ve been accumulating in balanced form (much easier than making them up myself). Overall they’re quite nice even without regard to their low price.

One thing I did notice, however, is that a couple of them don’t seat deeply enough in the Questyle QP2R’s 2.5mm jack to actually work. The same cable plugged into a 2.5mm IEMatch or into the A&K SP1000M works fine, so it’s something about the insertion depth, length, or diameter of the 2.5mm plug and the socket on the QP2R - but I’ve only noticed it with the Yinyoo cables (and not all of those either).

I can’t see, or measure, an actual difference between the cables with plugs that work and those that don’t, so it’s probably a very small tolerance issue between the connectors for the cable and player and likely both are at extremes in this case … so it’s just something to be aware of.