[ckvp]

I'm not sure why, or if I'm even using it right, but the active ground mode seems like it really expands the soundstage and detail of various headphones and IEMS I've used on it. Of course you lose some volume when you apply it, but I A/B tested several times with several pairs and I prefer the Active Ground every time. To give more detail, I am using 2.2mm balanced cables with all headphones and IEMS using these settings on my 5K with 3.0.4. I also run these with 20 band PEQ and hybrid fast roll-off filter.

Anyone know exactly what the Active Ground is doing? Is this its intended use? Why does it make all my sets sound much more alive?

 

[Hypops]

I'm not sure why, or if I'm even using it right, but the active ground mode seems like it really expands the soundstage and detail of various headphones and IEMS I've used on it. Of course you lose some volume when you apply it, but I A/B tested several times with several pairs and I prefer the Active Ground every time. To give more detail, I am using 2.2mm balanced cables with all headphones and IEMS using these settings on my 5K with 3.0.4. I also run these with 20 band PEQ and hybrid fast roll-off filter.


Anyone know exactly what the Active Ground is doing? Is this its intended use? Why does it make all my sets sound much more alive?

Pretty sure that just turns the 2.5mm connection into a single ended (rather than balanced) connection. I think what you’ve discovered is that you prefer the sound of single ended to balanced.

 

[ckvp]

Pretty sure that just turns the 2.5mm connection into a single ended (rather than balanced) connection. I think what you’ve discovered is that you prefer the sound of single ended to balanced.

That makes sense, but are you certain that is all it is doing? Doesn't a single ended connection only use a passive ground? Here, we specifically have an active ground.

See this reddit thread as well: https://www.reddit.com/r/headphones...anyone_explain_the_technical_differences_and/

Here is a diagram detailing the difference between single ended and Active Grounding, here Active GND.

 

[Hypops]

That makes sense, but are you certain that is all it is doing? Doesn't a single ended connection only use a passive ground? Here, we specifically have an active ground.

See this reddit thread as well: https://www.reddit.com/r/headphones...anyone_explain_the_technical_differences_and/

Here is a diagram detailing the difference between single ended and Active Grounding, here Active GND.

As I understand it, it’s just a different way of uniting the two grounds (so you don’t fry headphones using an unbalanced 2.5mm cable). On paper, it shouldn’t be audibly different.

As an aside, I’m also reasonably confident that the 2.5mm balanced connection on the 5K is just for convenience. The 5K isn’t a differential circuit design (what some marketing people call “fully balanced”). So the only difference between the 2.5mm and 3.5mm outputs should just be in voltage output (usually just experienced as more loudness).

All of the above aside, weird things can happen with audio devices. Grounding schemes in particular are important in cable design, especially when it comes to power. I myself hear big differences between different power cables used with (large) amplifiers. So it’s entirely possible that what you’re hearing is a similar effect. I don’t have any 2.5mm cables to test myself, but I’m curious if others have had an experience like yours.

 

[XTF1]

I’m also reasonably confident that the 2.5mm balanced connection on the 5K is just for convenience. The 5K isn’t a differential circuit design (what some marketing people call “fully balanced”).

Not sure I understand your point: why do say it’s not differential? The 5K uses two ES9219C, each one being a dual channel DAC/Amp, so 4x channels total.

In SE mode, I believe only one of the ES9219’s is used, so it’s 2x DAC/Amp (I don’t think the above diagram is correct…).

The “balanced” mode is actually a dual mono (bridged) mode, it uses the 4x individual DAC/Amp, but is not “fully balancing” the output impedances.
EDIT: it’s all about getting more power…

The “active ground” ties the two “-“ together, to a floating ground. The 4x channels are used, two of them being at the same virtual 0V. The potential benefit compared to SE is more current capability (only a consideration for very low-impedance , power-hungry IEM/HP), and a “ground” that is isolated (floating) from the USB port GND (only a consideration in USB wired mode and if ground loop is a problem). It may also improve noise, but I haven’t seen measurements…

 

[yaerb]

I guess it's a reimplemented version of this? their second reply there has more detail.
https://forum.qudelix.com/post/ghost-ground-mode-10565172
seems that they say here it would be the same functional sound as regular 2.5mm balanced

unless you mean 3.5mm vs active ground.
when I first got 5k everything I expected/read was just more available power but my experience was that slight soundstage/separation effect, which was good, but it diffused the bass a bit as well like a reverse crossfeed almost. almost stayed single ended for the bass.

 

[XTF1]

I guess it's a reimplemented version of this? their second reply there has more detail.
https://forum.qudelix.com/post/ghost-ground-mode-10565172
seems that they say here it would be the same functional sound as regular 2.5mm balanced

unless you mean 3.5mm vs active ground.
when I first got 5k everything I expected/read was just more available power but my experience was that slight soundstage/separation effect, which was good, but it diffused the bass a bit as well like a reverse crossfeed almost. almost stayed single ended for the bass.

I believe you are correct about the sound of 2.5 “active ground” vs. 2.5 “balanced”: not much difference if any. But the purpose of active ground is precisely for these HP/IEM that cannot be wired “balanced”, or these amps that have SE-only inputs: active ground can bring some benefits vs. 3.5 SE.

 

[yaerb]

oh yeah I should have quoted the first ckvp post, I wasn't sure what they were hearing an improvement between

 

[Random Lunatic]

Amongst other bad things to happen with the recent update, Qudelix for some reason added some crusty voice saying “power off” when turning off the device, instead of the simple “click” it used to have.
Anyone know a way to revert that?