To Balance or Not to Balance?
That is the question. Whether ‘tis nobler to buy a balanced amp or DAC or an unbalanced (or single-ended, aka SE, the two terms are interchangeable) amp or DAC is the focus of this post. There have been lots of questions around this forum about whether a balanced amp or DAC is better than a SE amp or DAC. Should you explore balanced? Is balanced better? It’s understandably confusing. After all, in the English language, ‘balance’ is often used in the context of describing something good or desirable or steady. So, I’m going to attempt to answer that question here with just enough detail to make it clear without getting horribly wordy. If ever you see someone asking this basic question on the forum, politely direct them here. New people join our hobby all the time and will need this information.
What’s the Bottom Line So I Don’t Have to Read 2000 Words?
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Your headphones only care about balanced/SE if they’re built to
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Balanced matters most between amp and DAC or on long signal runs between a source and mixer/preamp
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Balanced does not inherently sound better – arguably the opposite is true at a given price point – but if a device is designed to be balanced it will sound better being used balanced
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There’s no need to seek out a balanced signal chain unless you have noise issues in your system, but at the same time balanced shouldn’t be avoided if the gear you’re interested in has the features and sound you’re looking for.
But you expect more explanation for those points. So here it is…
What Does “Balanced” Mean in an Audio Circuit?
Essentially a balanced audio device separates the signal paths for the left and right stereo channels whereas a SE audio device runs both channels next to each other through a single signal path that is built to handle two channels of information simultaneously. For an amplifier in particular, a balanced topology requires two independent amplifier stages. In a balanced amp, the two amplifier stages will draw from the same power supply, but the signals for the left and right channels are amplified separately. If a balanced headphone connection is used, the two signals will never come back together – for lack of a better description. For more explanation, @Mazeframe did a nice post here: Balanced and Unbalanced Signal.
Your Headphone Doesn’t Care Unless It’s Made to Care
For the driver of a headphone or speaker – the assembly that actually vibrates back and forth to create sound waves – the question of it being balanced or SE does not apply. All drivers have two electrical contacts. Those contacts will be labeled as “+” or “–“ or will have some sort of label/indicator on one of the contacts. Because audio signals are alternating current, both contacts spend an equal amount of time being the positive and the negative. Thus, that labeling only helps whoever wires the drivers to get phasing correct. Correct phasing means that if both R and L drivers are fed an identical signal, they will move out together and in together. If they are wired backward – or out of phase – one will move out while the other moves in. For audio, that’s not good. The point is, it doesn’t matter to the drivers if they get connected to a balanced or SE signal chain. The electrical signal looks the same to them either way. However, it is somewhat common for a completely assembled headphone to be wired for SE operation only. Alternatively, a headphone can be wired so that it can be either balanced or SE depending on the type of cables used to connect it to its amplifier.
A good rule of thumb is that if a headphone has detachable, dual-entry cables, it can be run connected to either a balanced or SE headphone output depending on what kind of cable is used. If a headphone has single-entry for its cable, it’s very likely it can only be powered from the SE output of an amplifier:
(On the left is an example of a dual-entry detachable headphone cabling system. Connections of this type can use either balanced or SE cables. On the right is a single-entry headphone cabling system. The single entry means that this headphone has been internally wired to only be safe to use with a SE headphone amplifier output.)
Dual-entry, detachable cabling systems are by far the most common for audiophile headphones anymore. There are exceptions, though. Audio Technica has several models like the one pictured above that are single-entry SE-wired. Beyerdynamic’s DT series, Neumann NDH-20, most V-MODAs, and headphones built on the Fostex T?0RP line are other common examples. [Some of those Fostex RP headphones have been or can be modded to be single-entry balanced, though] Less common but still extant are examples of dual-entry but attached cable headphones like the older Fostex TH-X00 line and some Grado models. These headphones’ attached cables are terminated in a SE plug and should only be used with SE amplifier outputs.
The point here is your headphone does not care if the amp or DAC are balanced or SE unless the maker wires them to be SE only. And, if your headphone has a dual-entry, detachable cabling system, it can be powered from either the balanced or SE outputs of a headphone amp with the appropriate cables.
So Where Does Balanced Matter?
The place where balanced topology and connections matter is between the DAC and the amp or between a source component like a CD player and a preamp (however, that’s still technically between DAC and amp). In professional audio applications, balanced also matters between microphone and mixer or recording device. The reasons for balanced in the signal path of the source chain (source chain includes the actual source of the music like CD player or streamer, DAC, and amplifier) all have to do with how well the system handles undesirable noise. Let’s explore this a bit further.
It’s All About the Noise
All electrical circuits – and especially AC circuits – both create and have to handle noise in some fashion. Here “noise” just means part of the electrical signal that shouldn’t be there. Sources of undesirable noise can be internal and result from circuit elements interacting with each other, or they can be external due to electromagnetic interference or dirty/inconsistent power. Balanced electrical circuits are very good at handling external sources of noise. SE circuits inherently generate less internal noise. Balanced circuits separate grounding lines from signal lines and therefore are not nearly as susceptible to ground loops or external EM interference like radio signals. Professional audio uses balanced almost everywhere because cable runs are often long – increasing the likelihood of picking up EM interference – and cabling also gets crossed and tangled a lot which means they can electrically interfere with each other more. Home audio applications often use short cable runs and it’s more feasible to manage cabling (if you want, lol). The trade-off is balanced amps and DACs will generate more internal noise because their construction requires nearly double the component count compared to SE amps or DACs. Here “component” refers to all the individual circuit elements such as resistors, capacitors, inductors, transistors, etc. Thus, “component count” means the total number of those things in the amp or DAC. Since a balanced design requires essentially double the number of parts as a SE design, it will generate about twice the amount of noise – raising the noise floor. But, if there is a source of troublesome external noise somewhere, an SE design will be far less equipped to handle it and the noise will often be audible.
But, Does Balanced Sound Better?
No. Not automatically or inherently, anyway. There is a balance (haha) here too. Because a balanced design requires twice the number of parts, the cost is going to be higher. That means, in theory, a totally SE design and totally balanced design at the same price would actually favor the SE design in terms of performance; having to buy fewer parts means being able to buy better parts for the same amount of money which often translates to better subjective performance. However, there are a lot of variables here, not the least of which is design quality and part selection. Sound quality has a lot of factors and there is really no good way to compare balanced vs. SE sound quality because there are too many variables.
Generally speaking, a balanced design will sound better when its balanced design is fully used. In other words, if an amp is designed to be balanced and has a balanced headphone output, that balanced output should be used and will have the higher performance. Likewise, if a DAC has balanced outputs it was likely designed to be balanced and will sound better from that output. In these cases, the SE connections/headphone output is included as a convenience, but to get them the balanced signal has to be recombined somehow, and that recombination often comes at a sonic price. As price goes up the performance gap between the balanced and SE connections will drop because the added cost allows for more care to be taken in the design of those SE connections. But, especially under $1000, if an amp or DAC is balanced, it will perform noticeably better being used that way. At the other end, the cheapest gear is going to be SE because the component count is low AND the parts are cheap. Sometimes balanced amplifiers have ridiculous power output specs and are significantly less powerful from their SE outputs, which might create the impression that balanced can be more powerful generally. That’s also not true. Often to get a SE output on a balanced amp, just one internal amplifier stages is use, which means one amp is now driving both channels instead of just one. Also, SE amps can be designed to be very powerful (see: Schiit Lyr 3, Lake People G111, Cayin HA-1AMK2 tube amp - all can bring the pain from a SE output when needed and are priced under 1000USD).
How about some examples to make the above clearer? The Monolith Liquid Platinum amp is a classic example. It sounds very good from its balanced headphone output and somewhat mediocre for the price from its SE headphone output. It’s an amp that essentially tacked on an SE headphone output for convenience and had to do some signal recombination to pull it off.
To my knowledge, the Schiit Jotunheim 2 amp is the about the only balanced amp I know of under $1000 that sounds roughly equally good form both SE and balanced headphone outputs but with slightly different sound signatures, and that’s because the designers made it a point to build it that way, but that achievement has consequences.
Several budget and mid-tier amps have both balanced and SE headphone outputs but are fully SE in design with the balanced output tacked on as a convenience. Most THX amps are this way, and the Drop Liquid Carbon and Cavalli Tube Hybrid are other examples. These amps sound identical from SE and balanced outputs because the balanced output is just included after the SE output stage. It’s far easier to put a balanced output on a SE amp than a SE output on a balanced amp.
There are a handful of amps with balanced line-level inputs but only SE headphone outputs. The Rupert Neve RNHP, several amps from Lake People/Violectric (same company), and Geshelli Labs Archel 2.5 Pro are examples. These amps take full advantage of the benefits of being balanced where it counts – between amp and DAC – to eliminate unwanted noise and then amplify signals in SE fashion because it ultimately does not matter to the headphone whether the amp is balanced or SE.
So It Kinda Sounds Like Balanced is Unnecessary for Home Use?
In some sense that’s true, but there are exceptions. Over the past 10-15 years computers have become increasingly common audio sources, increasing the need for balanced designs for home use somewhat. Computers are very noisy audio sources. They have dozens of circuits in them going every which way which makes them a haven for noisy electrical signals. Desktop computers in particular can be very susceptible to ground loops. Optical digital audio connections can clean up audio signals, but don’t carry all of the audio signals we might want to use such as DSD or MQA. USB connections carry all the audio signals we want from computer to DAC but with them also comes all that noise. A balanced source chain can take out all that undesirable noise. Laptop computers and battery powered devices such as digital audio players (DAPs), smartphones, or tablets that can also be connected to a DAC via USB are far less likely to generate ground loop noise, though. IMO you should only be intentional about buying balanced gear if you have a noise issue to solve. Otherwise, buying balanced should just be a consequence of a piece having all the other features and sound signature that you’re looking for.
But What If I’m Poor and Have A Ground Loop? Is Balanced My Only Option?
Not necessarily. I’ve had ground loop issues and have had reasonably good success with simple $10 RCA ground loop isolators between my DAC and amp. If you use a DAC/amp combo unit that is connected via USB, you can try things like iFi’s iDefender or USB ground loop isolators. Even so, a balanced source chain is the best way to take out that ground loop noise.
OK the main points were:
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Your headphones only care about balanced/SE if they’re built to
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Balanced matters most between amp and DAC or on long signal runs between a source and mixer/preamp
-
Balanced does not inherently sound better – arguably the opposite is true at a given price point – but if a device is designed to be balanced it will sound better being used balanced
-
There’s no need to seek out a balanced signal chain unless you have noise issues in your system but at the same time balanced shouldn’t be avoided if the gear you’re interested in has the features and sound you’re looking for.
Hopefully I’ve made the case for them. If you have further questions, post them below. We have some very knowledgeable people around here and I’m sure we can get you an answer.
Thanks for reading and enjoy the music! 
Note: I’m happy to update this piece if anyone suggests better ways to say it. PM me if you have feedback.
