[PurpleAngel]

Thank you so much for the detailed description! I have two questions, though:
1. I understand that when you say "line-output (RCA)" and "the RCA jacks" you mean to same output - "2 speakers" line out, left + right. You first mention that they use all three op-amps, then that they bypass the headphone amplifier. The latter would mean that the RCA connection only engages the op-amp in the buffer slot, whereas the headphone jack uses 2 headphone op-amps. What are you referring to then when you mention the RCA line-out using all three op-amps?
2. None of the options you've described involves all three op-amps being disengaged. Does it mean that even when I'm using the IEM setting through the headphone jack, at least one of the card's op-amps is still engaged? It is the only setting where the sound signature seems quite flat (meaning balanced and detailed) so I was inclined to think that this setting bypasses all of the card's op-amps (delivering the sound straight from the card's DAC). Thanks!

The line-output (RCA) jacks can also be referred to as the Speaker output.
Analog Out setting in control panel, Speaker Out send the signal to the RCA jacks, Headphone setting sends the signal to the headphone jack.
So when the STX II is set to "Speaker", the analog line signal that comes out of the DAC, that signal goes thru the two I/V op-amps, then runs thru the buffer (low pass filter) op-amp, then goes to the RCA jacks.
When the STX II is set to "Headphone", the analog line signal that comes out the DAC, that signal goes thru the two I/V op-amps, then the signal goes straight to the headphone jack.

 

[Mista Lova Lova]

I have emailed Asus asking if there is a way to use the card in a DAC-only mode, here's the reply I got:

" No it is not possible to be used as DAC, no settings to bypass op-amps "

So it seems that even in the "IEM" setting one of the op-amps is still engaged (although to my ears this settings produces by far the cleanest and most detailed sound). I'll probably end up using the card to power up my monitors and subwoofer and will get an external DAC and amp for my headphones.

Thanks for your help!

 

[ray555]

creative has stereo direct which is kinda neat

 

[reddeath]

Hi, I have few questions regarding this STX II card, which I have been using for some years now by the way. In stock configuration.

1. For driving a 50 ohm headphones (HD599), which output is expected to be better:
- RCA out to logitech speakers (with THX logo), which have a headphone plug on the control unit (amplification done in the speakers, but no technical data on the amp there)
- Headphone out on the card

2. Is there any way to make a keyboard shortcut to switch between RCA and headphone outputs, instead of going to the control app and using a dropdown there? It is mostly the reason why I have been using the plug on the speakers controller which has a volume knob.

3. Do you think it is worth to buy an external DAC to upgrade over STX II and improve sound quality? Something like SMSL M500, connected to the PC with USB. Would I hear distinct improvement?

 

[PurpleAngel]

The STX II comes with some nice DAC chips, might be better to upgrade the op-amps (operational amplifiers) on the STX II
I would rather plug the HD599 into the STX II headphone jack, then the Logitech's, but it's your ears that decide which sounds better to you.

 

[reddeath]

The STX II comes with some nice DAC chips, might be better to upgrade the op-amps (operational amplifiers) on the STX II
I would rather plug the HD599 into the STX II headphone jack, then the Logitech's, but it's your ears that decide which sounds better to you.

How do I upgrade op-amps (operational amplifiers)?

 

[18000rpm]

1. For driving a 50 ohm headphones (HD599), which output is expected to be better:
- RCA out to logitech speakers (with THX logo), which have a headphone plug on the control unit (amplification done in the speakers, but no technical data on the amp there)
- Headphone out on the card

If your headphone is plugged into your Logitech speakers then I'm pretty sure the output voltage is handled by the Logitech and likely not as good as the Xonar. The Xonar has a very high quality dedicated headphone amp which is especially helpful for headphones that are difficult to drive.

3. Do you think it is worth to buy an external DAC to upgrade over STX II and improve sound quality? Something like SMSL M500, connected to the PC with USB. Would I hear distinct improvement?

I have been using the Essence STX II for many years and have been extremely pleased with its performance but I recently added an SMSL M400 DAC. Holy crap the improvement in sound quality is astounding. I don't use headphones but rather connect the output of the Xonar/SMSL directly to an amplifier (beefy Bryston 4B SST) so your mileage may vary. Before I bought the M400 I auditioned the M500 (which is one step below the M400) and that sounds very good too. Both also support MQA so TIDAL sounds great.

Now I use the Xonar for 5.1 and SMSL for stereo. The SMSL is connected via USB and when I turn it on, audio automatically switches to it so it's pretty convenient.

 

[Telin]

Hi, I have few questions regarding this STX II card, which I have been using for some years now by the way. In stock configuration.

1. For driving a 50 ohm headphones (HD599), which output is expected to be better:
- RCA out to logitech speakers (with THX logo), which have a headphone plug on the control unit (amplification done in the speakers, but no technical data on the amp there)
- Headphone out on the card

2. Is there any way to make a keyboard shortcut to switch between RCA and headphone outputs, instead of going to the control app and using a dropdown there? It is mostly the reason why I have been using the plug on the speakers controller which has a volume knob.

3. Do you think it is worth to buy an external DAC to upgrade over STX II and improve sound quality? Something like SMSL M500, connected to the PC with USB. Would I hear distinct improvement?

1. I would say Headphone jack from the Essence. Logitech is not exactly known to put audiophile orientated products on the market. But just try and hear what you like best.

2. Yes it's called XonarSwitch works best with the Unified drivers which you should be using anyway. Seems to be in a permanent beta state but it worked fine for me on Windows 10 Enterprise LTSB 2016.

3. Depends.. Will the sound quality improve, yes. Will improve enough to justify the couple hundred dollar/euro.. only you can answer that.

 

[reddeath]

If your headphone is plugged into your Logitech speakers then I'm pretty sure the output voltage is handled by the Logitech and likely not as good as the Xonar. The Xonar has a very high quality dedicated headphone amp which is especially helpful for headphones that are difficult to drive.



I have been using the Essence STX II for many years and have been extremely pleased with its performance but I recently added an SMSL M400 DAC. Holy crap the improvement in sound quality is astounding. I don't use headphones but rather connect the output of the Xonar/SMSL directly to an amplifier (beefy Bryston 4B SST) so your mileage may vary. Before I bought the M400 I auditioned the M500 (which is one step below the M400) and that sounds very good too. Both also support MQA so TIDAL sounds great.

Now I use the Xonar for 5.1 and SMSL for stereo. The SMSL is connected via USB and when I turn it on, audio automatically switches to it so it's pretty convenient.

How do you use xonar for 5.1 exactly? Do you use the addon 7.1 card? Are you on Windows, to be able to switch the audio cards automatically?

 

[PurpleAngel]

I have emailed Asus asking if there is a way to use the card in a DAC-only mode, here's the reply I got:

" No it is not possible to be used as DAC, no settings to bypass op-amps "

So it seems that even in the "IEM" setting one of the op-amps is still engaged (although to my ears this settings produces by far the cleanest and most detailed sound). I'll probably end up using the card to power up my monitors and subwoofer and will get an external DAC and amp for my headphones.

Thanks for your help!

Just hook up the STX II's line-output (RCA) jack to any external headphone amplifier, then connect the headphone amplifier's line-output to the input's on your monitors.

 

[kefs]

Just hook up the STX II's line-output (RCA) jack to any external headphone amplifier, then connect the headphone amplifier's line-output to the input's on your monitors.

Exactly how i use it with great results

 

[18000rpm]

How do you use xonar for 5.1 exactly? Do you use the addon 7.1 card? Are you on Windows, to be able to switch the audio cards automatically?

Yes I have the 7.1 add-on card.

 

[reddeath]

1. I would say Headphone jack from the Essence. Logitech is not exactly known to put audiophile orientated products on the market. But just try and hear what you like best.

2. Yes it's called XonarSwitch works best with the Unified drivers which you should be using anyway. Seems to be in a permanent beta state but it worked fine for me on Windows 10 Enterprise LTSB 2016.

3. Depends.. Will the sound quality improve, yes. Will improve enough to justify the couple hundred dollar/euro.. only you can answer that.

I am not using the Unified drivers, just the stock version, which always works. Looking at the list of issues that the modded driver has, I just don't bother using it.
But I am interested in the XonarSwitch. Does it work at all with the standard drivers? Will it cause BSODs?

 

[BallisticGT3]

Do you think it is worth to buy an external DAC to upgrade over STX II and improve sound quality?

I've been an STXII user for a while, thinking that I was getting the best possible sound quality out of my Pc, but then I started to question this.
I'm not knocking the STXII, it's a great sound card and I found it better than the Creative ones.
I was feeding the analogue o/p into a decent external amp and speakers, but listening to music sounded nothing like my main hifi system in the lounge.

I searched the Internet for information on how to get the best possible sound quality from a Pc and discussed the matter with my goto hifi dealer, who made some suggestions and very kindly loaned me some kit to experiment with.

Here's what I found;
1) Changing the op-amps on the STXII does make a difference and will alter the sound characteristics, depending on your preferences, but this isn't where the biggest gains are to be made.
2) Taking the digital o/p from the STXII, instead of analogue, and feeding it into an external DAC, in this case a Chord QuTest, makes the biggest difference IMO.
3) Removing the STXII from my Pc altogether and connecting from usb to the Qutest sounded better still.
4) I tried an M-Scaler with the QuTest, which made a marginal improvement, but didn't sound as good as replacing the M-Scaler/QuTest with a HugoTT2.
5) I now have usb from the Pc into HugoTT2, into Bryston 2.5b3 and Dali Opticon 6 (soon to be replaced with Opticon 8 mk2) and the difference in sound quality from where I first started (STXII analogue o/p into Roksan Caspian mk2 and Opticon 6) is night and day.

I hope this information is of help to anyone looking to improve the sound quality from their Pc.

 

[Telin]

2) Taking the digital o/p from the STXII, instead of analogue, and feeding it into an external DAC, in this case a Chord QuTest, makes the biggest difference IMO.

In that setup you just bypass the entire card and the Essence basically becomes a very expensive optical out add-on card. The same optical out you already get for free on most reasonable recent motherboards.