[rhern213]

On Hugo 2 optical sounds the same as USB - and this is via headphones, so no ground loop from the source, and hence no ground currents. It changes as soon as you ground the connection, which normally happens with Qutest, as you will connect an amp on the outputs. Now to reduce the ground currents (RF noise into the ground plane of the DAC) I use galvanic isolation and RF filters - but it's not possible to totally eliminate the issue. If you use a low power, simple source, then USB sounds the same as optical (particularly with battery powered sources), so use the optical as your benchmark. To do the listening tests correctly you need to disconnect all other sources. Coax has no galvanic isolation, and direct coupling to the grounds, so will always be the brighter sounding input.

The reason it sounds brighter is RF noise when interfering with analogue creates more noise floor modulation, which makes it sound brighter.

Thanks for the explanation Rob! I didn't realize the optical port was also isolated, I thought it was only the USB. Was this done in the Qutest's optical port by design, or is it simply the technology of optical connections themselves that are free from ground noise?

My source is an Auralic Mini with an internal SSD, so I think I can classify it as simple. My Qutest is powered by a battery pack, but the Auralic is just through the standard supplied wall-wart. I guess there's also the question of whether the Auralic mini outputs a cleaner signal through USB or Optical.

 

[Zzt231gr]

But Rob,just to be clear-are you sure that every CD transport outputs noise through coaxial output?

 

[Rob Watts]

Thanks for the explanation Rob! I didn't realize the optical port was also isolated, I thought it was only the USB. Was this done in the Qutest's optical port by design, or is it simply the technology of optical connections themselves that are free from ground noise?

My source is an Auralic Mini with an internal SSD, so I think I can classify it as simple. My Qutest is powered by a battery pack, but the Auralic is just through the standard supplied wall-wart. I guess there's also the question of whether the Auralic mini outputs a cleaner signal through USB or Optical.

Yes optical data is transmitted through light only, so no electrical connection at all. It's the perfect galvanic isolation, as the coupling capacitance is almost zero.

But Rob,just to be clear-are you sure that every CD transport outputs noise through coaxial output?

Yes, all electrical connections from a digital source will have RF noise on the ground. Even if it is galvanically isolated, there is still a coupling capacitance, which degrades the isolation at higher frequencies (particularly in the GHz range).

 

[Zzt231gr]

Hey man, I just compared the Optical vs. the RCA output from the Cambridge CXC transport, both sound good, but I prefer the RCA to BNC cable over the optical connection, seems to sound fuller and has a better soundstage. Not sure how much is down to the cables ( Oehlbach optical cable and Ghent Audio RCA to BNC 75 Ohm cable ) and how much is the connection type, but I think the RCA to BNC cable sounds better. Just my 2 cents... I don’t think you can go wrong with the Belden.

Our fellow member had the exact opposite opinion on the sound between those inputs.Can you explain that?

 

[Rob Watts]

It depends what he means by the terms "fuller" and "better soundstage".

If fuller means warmer, richer and smoother, then no that doesn't make sense to me. But if fuller is a brighter sound, then it's just the case of thinking the extra noise floor modulation is more transparency - it can be impossible to tell the difference.

Coax can have worse depth, and the converse of this is the perception of more width - flat and wide, against less width but much deeper soundstage with better layering.

 

[sasaki99]

I have both H2 and Qutest, the Qutest just arrived a week ago because I just quit the headphone world and go into hifi 2CH. The H2 sound more natural to me, more organic while the Qutest sounds bright. I also prepared an AQ diamond USB cable for the Qutest. When pairing I found the qutest is just too bright, really bright, thought it would sound the same as H2.

Sooo, what’s your opinion about H2 and Dave. I prefer neutral sound, not the bright sound, if I say the Qutest is bright, what you would say about the Dave.

Thanks!

 

[sasaki99]

I have both H2 and Qutest, the Qutest just arrived a week ago because I just quit the headphone world and go into hifi 2CH. The H2 sound more natural to me, more organic while the Qutest sounds bright. I also prepared an AQ diamond USB cable for the Qutest. When pairing I found the qutest is just too bright, really bright, thought it would sound the same as H2.

Sooo, what’s your opinion about H2 and Dave. I prefer neutral sound, not the bright sound, if I say the Qutest is bright, what you would say about the Dave.

Thanks!

 

[Zzt231gr]

It depends what he means by the terms "fuller" and "better soundstage".

If fuller means warmer, richer and smoother, then no that doesn't make sense to me. But if fuller is a brighter sound, then it's just the case of thinking the extra noise floor modulation is more transparency - it can be impossible to tell the difference.

Coax can have worse depth, and the converse of this is the perception of more width - flat and wide, against less width but much deeper soundstage with better layering.

Very helpful comment.I must find the time tonight to test it myself.

 

[kovacs]

It depends what he means by the terms "fuller" and "better soundstage".

If fuller means warmer, richer and smoother, then no that doesn't make sense to me. But if fuller is a brighter sound, then it's just the case of thinking the extra noise floor modulation is more transparency - it can be impossible to tell the difference.

Coax can have worse depth, and the converse of this is the perception of more width - flat and wide, against less width but much deeper soundstage with better layering.

It's been a while since I did this test, but from what I remember it did really sound fuller and the soundstage did seem deeper ( I don't really pay much attention to soundstage width because it's always pretty poor in my room even with a lot of acoustic treatment ). I could redo the test, but I don't think you can entirely predict which will sound better based on the supposed technical superiority of optical, other factors than just RFI are at play here. The electrical signal has to be converted to an optical signal, send through a pretty basic optical cable and back to an electrical one. I find it hard to believe that all this can be done without loss of information or introducing it's own set of problems. That said I will try the optical connection again and specifically listen to the things you describe.

 

[Zzt231gr]

It's been a while since I did this test, but from what I remember it did really sound fuller and the soundstage did seem deeper ( I don't really pay much attention to soundstage width because it's always pretty poor in my room even with a lot of accoustic treatment ). I could redo the test, but I don't think you can entirely predict which will sound better based on the supposed technical superiority of optical, other factors than just RFI are at play here. The electrical signal has to be converted to an optical signal, send through a pretty basic optical cable and back to an electrical one. I find it hard to believe that all this can be done without loss of information or introducing it's own set of problems. That said I will try the optical connection again and specifically listen to the things you describe.

You do that-I will try to when I find the time.

Treating with broadband absorption your side first reflection points for both speakers will give all the width in the world.I frequently hear the instruments outside of the speakers precisely-if the rec allows.

 

[kovacs]

You do that-I will try to when I find the time.

Treating with broadband absorption your side first reflection points for both speakers will give all the width in the world.I frequently hear the instruments outside of the speakers precisely-if the rec allows.

Believe me I've tried everything to recreate the soundstage I had in my previous room, I've got a big diffuser ( https://www.thomann.de/be/the_takustik_sc_diffusor.htm ), some absorbers and a big rug. I've even completely rearranged the furniture, it's not exactly pretty but at least now it sounds pretty decent. Soundstage depth is good but I can't get the speakers to completely disappear as much as I want, but right now this is as good as it gets without placing more diffusers in the middle of the room.

 

[Zzt231gr]

Believe me I've tried everything to recreate the soundstage I had in my previous room, I've got a big diffuser ( https://www.thomann.de/be/the_takustik_sc_diffusor.htm ), some absorbers and a big rug. I've even completely rearranged the furniture, it's not exactly pretty but at least now it sounds pretty decent. Soundstage depth is good but I can't get the speakers to completely disappear as much as I want, but right now this is as good as it gets without placing more diffusers in the middle of the room.

Can you post some pictures of your space?Diffusers don't work well below 2 meters distance.Don't want to insult,but it must be something wrong with your treatment placement.In my room,everyone praises my holographic imaging and the disappearance of the speakers!

 

[jayz]

It depends what he means by the terms "fuller" and "better soundstage".

If fuller means warmer, richer and smoother, then no that doesn't make sense to me. But if fuller is a brighter sound, then it's just the case of thinking the extra noise floor modulation is more transparency - it can be impossible to tell the difference.

Coax can have worse depth, and the converse of this is the perception of more width - flat and wide, against less width but much deeper soundstage with better layering.

That seem to suggest that if we are interested in maximum depth of perception and layering, for PCM up to 192/24, there is no advantage whatsoever in using Coax instead of Optical.

If that is the case, I should go back to Optical and see. Would be good to know.

 

[Lodwales81]

So optical is a better option than USB even though optical does not handle anything. Above 24/176

That seem to suggest that if we are interested in maximum depth of perception and layering, for PCM up to 192/24, there is no advantage whatsoever in using Coax instead of Optical.

If that is the case, I should go back to Optical and see. Would be good to know.

 

[AlexB73]

I compared optical (QED Reference) to coaxial (Belkin Professional) with both 2Qute and Qutest.
Coaxial always sounds more deep, reach in tone and natural. Optical sounds clinical and artificial in comparison.