Bryston BHA-1 fed by Chord Hugo 2 via Unbalanced RCA - Which BHA-1 output to use?

[rumorconsumer]

I am currently using the Bryston BHA-1 as my headphone amplifier, paired with a Chord Hugo 2 DAC and Grado HP100 SE headphones, and I wanted to ask for your advice on the optimal connection path.

Currently, I have the Hugo 2 connected to the BHA-1 via single-ended RCA inputs, as the Hugo 2 does not provide a true balanced output. However, I am using the balanced 4-pin XLR headphone output on the BHA-1 to drive my Grados. Given that the original DAC signal is single-ended, I am wondering whether there is any meaningful benefit to continuing to use the balanced output, or whether I should switch to single-ended for the entire chain and use the ¼” single-ended headphone output on the BHA-1 instead.

Chord’s Perspective on Single-Ended vs. Balanced:

Chord Electronics has stated that single-ended is inherently more transparent than balanced, as it requires fewer conversion steps and avoids additional circuitry. They explain that their Pulse Array DACs are designed to operate as single-ended outputs, unlike conventional delta-sigma DACs that are often balanced to mitigate substrate noise. Because Chord’s FPGA-based Pulse Array architecture does not suffer from these noise issues, they argue that adding a balanced output stage would only add unnecessary conversion steps that could degrade sound quality rather than improve it. Be that as it may.

Given this, I want to make sure that my current setup is the most optimal for both transparency and performance.

My Questions:
1. Since the Hugo 2 is inherently single-ended, am I already optimizing the connection by using RCA inputs on the BHA-1?
2. Would there be any meaningful advantage to continuing to use the BHA-1’s balanced headphone output, given that the original source is single-ended? Or would I be better off using the ¼” single-ended headphone output to maintain a fully single-ended path?
3. Does the BHA-1 internally convert single-ended input to a balanced signal for amplification? If so, does this process introduce any audible benefits or drawbacks?

I would appreciate any insight you can provide on how the BHA-1 processes single-ended vs. balanced signals and whether I should optimize for a fully single-ended or partially balanced chain.

 

[tesarpa]

When you have all option at hand, why bother with theory? Try both options and let your ears decide. I have no clue about BHA internals, but I guess single ended output should provide cleaner signal. Balanced may provide more power, but Grados are not hungry, right?

 

[rumorconsumer]

When you have all option at hand, why bother with theory? Try both options and let your ears decide. I have no clue about BHA internals, but I guess single ended output should provide cleaner signal. Balanced may provide more power, but Grados are not hungry, right?

Correct not hungry. Im technical and I like to know these things. I can listen all day and Id rather know what the actual mechanisms are doing. Its both, listening and knowing what your HW is up to.

 

[Roseval]

Given that the original DAC signal is single-ended, I am wondering whether there is any meaningful benefit to continuing to use the balanced output

I'm afraid you are comparing apples and oranges because what they call balanced out in the headphone world has nothing to do with a balanced connection at line level.

A balanced connection as common in the pro-world is a 3 wire connection using a 3 pin XLR or a TRS jack.
It is used to connect DAC's, amps, active speakers, etc. at line level.
The 3 wires carry a hot, a cold (the inverse of the hot) and a ground.
At the receiver there is a differential amp comparing the hot and the cold and removing all common noise.

A "balanced" connection in the headphone world means something completely different.
It is a 4 wire connection, L+/L- and R+/R- between the amp and the headphone.
Nothing "balanced" about this symmetrical connection but as L and R no longer have a common ground, it allow for amplifier topologies with a floating ground like indeed a balanced amp. That is why this double single ended connection is called "balanced" in the headphone world.

If your headphone amp has a balanced out, it means that they are using 2 amps per channel. This doubles the power but also doubles the impedance and the distortion.
The only thing you can do is checking the specs. It might be that the single ended output has lower power but also lower impedance and distortion compared with the "balanced" output. But practice is all over the place. Sometimes the single ended is substantially worse compared with the balanced.

 

[rumorconsumer]

I'm afraid you are comparing apples and oranges because what they call balanced out in the headphone world has nothing to do with a balanced connection at line level.

A balanced connection as common in the pro-world is a 3 wire connection using a 3 pin XLR or a TRS jack.
It is used to connect DAC's, amps, active speakers, etc. at line level.
The 3 wires carry a hot, a cold (the inverse of the hot) and a ground.
At the receiver there is a differential amp comparing the hot and the cold and removing all common noise.

A "balanced" connection in the headphone world means something completely different.
It is a 4 wire connection, L+/L- and R+/R- between the amp and the headphone.
Nothing "balanced" about this symmetrical connection but as L and R no longer have a common ground, it allow for amplifier topologies with a floating ground like indeed a balanced amp. That is why this double single ended connection is called "balanced" in the headphone world.

If your headphone amp has a balanced out, it means that they are using 2 amps per channel. This doubles the power but also doubles the impedance and the distortion.
The only thing you can do is checking the specs. It might be that the single ended output has lower power but also lower impedance and distortion compared with the "balanced" output. But practice is all over the place. Sometimes the single ended is substantially worse compared with the balanced.

Appreciate the response—this is exactly the kind of thing I wanted to dig into. Totally agree that balanced line-level and balanced headphone drive are two completely different animals, and I get why that distinction matters. But what I’m really trying to figure out is whether, in this particular amp, there’s any meaningful downside to running balanced out when the source is single-ended.


I get the apples to oranges point, but I think the question still stands because it’s not just about whether headphone and line-level balanced are the same thing—it’s about what happens inside the amp when you start with an SE input but then run balanced output.

So here’s what I know so far:

• The BHA-1 is a fully discrete Class A balanced design, meaning it’s not just throwing in balanced outputs as an afterthought—it was built for that topology.

• When running balanced headphones, all four amplifiers are working—vs. only two in single-ended mode.

• Bryston actually markets balanced mode as the superior option, saying it offers better stability, resolution, and control (which makes sense when extra power is needed, but my Grados don’t exactly demand tons of power).

So the real question is how Bryston handles converting a single-ended input to a balanced signal internally.

• Is it just splitting the phase passively in a way that could introduce phase issues?

• Or is it actively balanced in a way that keeps the integrity of the signal intact?

Because if that conversion is totally clean, then there’s no real reason not to run balanced out—even if the Hugo 2 is single-ended—since I’d still be getting the benefits of lower crosstalk, better driver control, and full use of all four amps.

But if there’s some measurable or audible downside to how that conversion is done, then yeah, sticking to single-ended all the way through might make more sense.

I looked through Bryston’s manual and marketing materials, and they don’t mention any downsides to running balanced headphones from a single-ended input. If there was some kind of distortion penalty, I feel like they’d make that clear.

What I need to track down is SE vs. balanced distortion specs—because if SE actually measures cleaner, that’s a whole different conversation.

Have you ever seen anyone directly compare SE vs. balanced distortion numbers for the BHA-1? I’d love to see hard data if it’s out there.

 

[Roseval]

Assume a DAC and a amp.
If you connect them SE (Single Ended) you have a RCA cable and any distortion picked up by this cable can't be corrected. Most of the time there won't be any distortion as it is a shielded connection.
In the pro-world you have tons of gear. The change of picking up some distortion by the cable is higher. What do they do?
The output of a DAC is single ended. Connect a balun to this output and you have the original signal (the hot) and the balun takes care of flipping the phase (the cold). At the receiver there is a differential amp. It compares the hot and the (flipped) cold and any difference between the do is considered distortion (common noise rejection).
basically:
SE > RCA wire > SE
SE > balanced wire > SE

 

[rumorconsumer]

Assume a DAC and a amp.
If you connect them SE (Single Ended) you have a RCA cable and any distortion picked up by this cable can't be corrected. Most of the time there won't be any distortion as it is a shielded connection.
In the pro-world you have tons of gear. The change of picking up some distortion by the cable is higher. What do they do?
The output of a DAC is single ended. Connect a balun to this output and you have the original signal (the hot) and the balun takes care of flipping the phase (the cold). At the receiver there is a differential amp. It compares the hot and the (flipped) cold and any difference between the do is considered distortion (common noise rejection).
basically:
SE > RCA wire > SE
SE > balanced wire > SE

Yeah, totally get what you’re saying about balanced interconnects and noise rejection—that all makes sense in the pro audio world.

But I think the question is slightly different here. In a traditional pro audio scenario, balanced interconnects exist to reject noise over long cable runs—which is why you’d take an SE signal, use a balun to create a balanced version, and then let the differential amp at the receiving end cancel out any noise.

But in this case, we’re talking about a fully differential headphone amplifier (the BHA-1), where the entire internal signal path is balanced from input to output. So the question is less about cable noise rejection and more about how the BHA-1 itself handles a single-ended input before it gets amplified in its balanced topology.

Is it just doing a basic phase inversion at the input stage, or is it actively converting the signal in a way that retains full integrity? If it’s a clean and transparent process, then using balanced headphone output still makes sense because I’d be getting full use of all four amplifiers instead of just two. But if something in the conversion step introduces phase shift or distortion, then yeah, maybe single-ended out is the better option.

So while I get the apples and oranges comparison, I think the real question is: Does Bryston’s circuit design keep things transparent when taking SE in and outputting balanced? That’s what I’m still trying to track down.

Appreciate the discussion—this is exactly the kind of thing I like getting into!

 

[tesarpa]

Just checked manual https://bryston.com/wp-content/uploads/2020/06/300028BHA1.pdf, which contains full schematics of the amp. That should answer all your questions, if you can read it. I can’t, sorry.

 

[rumorconsumer]

Just checked manual https://bryston.com/wp-content/uploads/2020/06/300028BHA1.pdf, which contains full schematics of the amp. That should answer all your questions, if you can read it. I can’t, sorry.

Have read it; is not responsive to the question. Thanks tho!