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exdigguser147 t1_je7wtb4 wrote

Reply to comment by andysaurus_rex in Really enjoying my new $350 "budget" setup. HD660S and Topping DX1 by Jfox8

I would love to meet the person who can actually hear the difference between balanced and single ended in a headphone.

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blorg t1_je85oc2 wrote

Balanced typically has double the voltage and 3-4x the power which is easily audible if you have something that needs it. HD660S is not hard to drive though.

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entivoo t1_je8wq7c wrote

Balanced is not always the best I think, but most manufacturers simply put all of their resources to balanced output and input if their amp/dac has both single ended and balanced. At least for lower end amp/dac like the toppings. High end ones mostly have the same quality of sound between the balanced and single ended output or input.

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blorg t1_je8y1rk wrote

It's entirely possible to make a single ended amp that is as good as a balanced one, balanced isn't necessary in that regard. But it's often an easy/relatively cheap way to add more power, at a given pricepoint, or with a particular design. Particularly with small USB or battery powered stuff.

The person I was responding to doubted anyone "can actually hear the difference between balanced and single ended". But it provides in these type of devices typically 3-4x the power, and that's a very obvious difference, if you have something that needs it. HD660S doesn't need it.

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Shandriel t1_je8oahh wrote

I have 250 Ohms Beyer DT 990 and they comfortably run even on my Plenue D2

I mean, there must be a lot even more demanding headphones out there, but most desktop amps also deliver a lot more power...

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blorg t1_je8qn2o wrote

The Topping DX1 is more like a "super dongle" than a desktop amp, it's USB powered and has power output similar to higher powered dongles.

>280mW X 2 @32Ω THD+N<0.1 %
>190mW X 2 @64Ω THD+N<0.1 %
>51mW X 2 @300Ω THD+N<0.1 %

The Fiio K7 entry level desktop amp (to take an example), does a bit over 10 times the power of this, out of its balanced. You may not need this, but it's a lot more.

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Shandriel t1_je9895g wrote

I know, my desktop amp puts out 300mW @ 300 Ohm

whereas the Plenue D2 is somewhere around 10mW

yet, those are enough to go TOO loud on my 250Ohms Beyerdynamic DT 990

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exdigguser147 t1_je9w0t5 wrote

There's no conventional headphone in the world that takes more than 1.5W to power under 115db You just spouting fud. You may use an amp that has a little headroom for that 1.5w but that's more to the quality of the amp than the power requirement.

Balanced outputs are for speakers, because the power requirements are much higher and the cable runs are/can be longer.

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blorg t1_je9xtpk wrote

The Topping DX1 does 51mW @300Ω - 280mW @32Ω.

This is fine for the HD660S but it's nowhere near 1.5W.

Now obviously you can make a single ended amp that does 1.5W. But particularly in these small USB-powered devices, it seems easier/cheaper to get more power with a balanced output than increasing the power on single ended.

Everything else being equal, you get double the voltage balanced, which is 4x the power theoretically (and usually you'll get that into higher impedances) and typically at least 3x at lower impedances when you consider current limitations. This is a significant difference and will be audible if you need a headphone that needs the power.

Nothing about this is saying you need balanced rather than single ended for a given power level or that you need over 1.5W for most headphones (my HE6SE, Hifiman do recommend 2W@50Ω though, and I think it sort of needs this). Just that balanced does typically give substantially higher power and that is audible if you need it.

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exdigguser147 t1_jea913z wrote

They recommend an amp that does 2W @50Ω because amps are not rated for power in a standard method that accounts for the full frequency range. The headphone still only needs 1.5W max for 115db and that's 750mW per driver.

I dont know what you are on about with balanced = double voltage which means 4x power. Did you read that somewhere and not question it? Balanced does double the voltage, but the current does not change so power is only doubled.

You are applying opinions and feelings to physics.

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blorg t1_jeag0v3 wrote

The current does change though, current is proportional to voltage (Ohms law).

Double the voltage, double the current.

Power is the product of the voltage and current (Watt's law).

But you double one, you double the other. So double the voltage = double the current and as both are doubled, the power increases by the square of the voltage.

  • 2V @ 300Ω = 13.3 mW
  • 4V @ 300Ω = 53.3 mW

And this is actually the typical power you get out of 2V single ended / 4V balanced stuff.

Look for example here at actual measurements of the Moondrop MoonRiver 2 which does max 2V SE, 4V balanced.

At 300Ω, it is able to reach the full 2/4V without clipping and does ~13mW single ended, ~53mW balanced. At 68Ω, it's still hitting the full 2/4V and the power is ~59/235mW. The balanced power in both these cases is 4x exactly. So any headphone over 68Ω, you will get 4x the power on the balanced.

At low impedances, there can be a limit to current, so the amplifier will clip and you won't get 4x. You can see this here with 32Ω, where it gets 125mW single ended but only ~250mW balanced- and it then clips and distorts, rather than running out of voltage as in the other cases.

But you typically will get the full 4x at double voltage, into higher impedances.

Exactly how much at a given impedance depends on the design of the amp. But 4x is the theoretical increase in power, if current is not a limiting factor. And it typically won't be, into higher impedances. Check the spec sheets for some other amps with both, like the Topping A90D, you can see that 250mW SE but 1,000mW balanced into 300Ω. If you go all the way down to 16Ω, it's less, it's 3,300mW vs 9,800mW, i.e. 3x. Because there's a current limit. It's still over 2x though even at 16Ω.

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exdigguser147 t1_jeahfqx wrote

Ok, that's all well and good... you taught me something.

But there is no single driver in a headphone needing more than 750mW of power so my original point still stands, a headphone does not need or benefit from a balanced output.

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