Review and Measurements of Asus STX II PCI Sound Card

[Sythrix]

I actually have used this Card (STX II) for years and I am quite happy with it. I'm a bit puzzeled why it performed so badly. Might be, that it was defective?
Is there a way to measure it without PRO Equipment at home? I could do a comparison to a MSI X570 MEG ACE...

it is likely it was defective, yes. The card has been acting strangely, causing restarts in my computer when the relays click. As to whether or not the defects caused the poor measurements, or the extent of them, I cannot say. I have since removed the whole thing from my computer.

EDIT: Also, as was demonstrated through software, it's likely the drivers are simply poor. Asus does not care about this card and has not updated the drivers in a long, long time.

 

[altefrau]

Yes, the drivers have not been updated in a long time. But my card is running flawlessly anyways.

My new mainboard audio (X570 MEG ACE) sounds good too, but I need a dedicated headphone amplifier to drive 600 Ohm cans. The Asus card has enough power for that.

I’m simply not sure if I will get more (audible) quality if I buy a better DAC... if I can’t hear a difference between these two?

 

[LuckyLuke575]

And oh, to emphasize, op-amp "rolling" makes no difference. Again!

It's nice to do this proactively and preempt the fan boys / naysayers / subjectivists / it sounds good to me crowd

 

[LuckyLuke575]

A-weighting definitely improves things. They did not say they used one though on THD+N (SINAD):

I put more stock into odds on the bookies sheets down at the track than I do on DAC manufacturers' spec sheets these days

 

[BLMN]

Actually the "sweet spot" for THD in this card is -6dBFS, but my measurements in loopback shows me 0.0003% at -0.5dB. The unity tested must be damaged. The measurements below were made using LME49990 in the front end. Whith the original ICs it reaches 0.0003% THD at -6dBFS. The measurements below were taken in loopback.

 

[Baroma]

I'm currently using the ASUS Essence STX II sound card and have been for a number of years.
It's fitted in a tower case with well researched "budget" stuff.
I'll endorse the comments about the ASUS software. Tried it and was never happy with how it worked and sounded. Got the named alternative.
I took a look at the Uni Xonar display and it's showing a sample rate of PCM 44.1 KHz.
It's been that way for a couple of years and I like the sound.
A pair of above budget RCA cables are going into a Songken SA-700R amplifier and then to a pair of self built "Blastorama" speakers with 8" Eminence Beta-8A speakers. I disconnected the recommended horn tweeters as I didn't like them. Parts Express have recommended Eminence ATP:30 1" tweeters with crossovers and I'll probably get them one day.
I tried listening to a few of the test recordings used by reviewers of high end equipment and yes, they don't sound all that good on my gear.
Mostly I listen to Spotify.
The Songken has a bit of mains hum now and I sometimes have to "pat" it a couple of times to encourage the transformer to start transforming so I'm looking at upgrades.

 

[altefrau]

What did I do wrong? Levels were okay... But only the mainboard might be realistic?

 

[guenthi_r]

Buyed just for fun this Asus STX PCIe Card for 30 bucks and done a quick Loop Measurement with Arta (unweighted):

Changed the OpAmps in the I/V Section to LM4562 to get the lowest possible THD+N at -3dBFS.
Tested some other OpAmps, got some lower or higher noise but THD never gets below 0,00050% THD.
Only with the LM4562 i get 0,00043% THD.
Seems this is near the Limit of the PC1792A DAC:

Edit:
Changing I/V Opamps to OPA1656 i get a little less noise and THD:

 

[liquidlino]

Don't forget, the claim on the chipset / Headphone amp is: "Texas Instruments 6120A2*1 (120dB SNR, 100dB THD+N @ Vcc±12V, RL=600Ω, f=1kHz) 24-bit D-A Converter of Digital Sources" (from specs section of STX page on Asus website).

So the THD is only supposed to hit 100db - and you need to be in 24 bit mode to achieve this. So these results and saying it missed by xx db is a bit spurious really. Getting 96db in 16-bit is probably its engineered result.

 

[Ufasas]

i have asus strix soar 7.1, and found a used stx II on auction, would it be worth upgrading to stx II ? Or better get Schiit Fula 3/4 or Schiit Hel 1 / 2 using akg k702 and sony ma900 as main daily devices

 

[18000rpm]

I have a Xonar Essence STX II 7.1 (with the daughterboard) and also an SMSL M400 connected to my home theater (and music) PC.

Back when this was first released in 2014 (an age ago) the external DAC market was different than it is now, with many extremely good options at affordable prices.

But for me the #1 reason that I still use this is because it provides 7.1 channels, for movies and gaming. There is no reasonably priced external DAC that provides that.

 

[Xyrium]

I had the card too. However, I believe most on board audio does 7.1 these days, no?

 

[18000rpm]

I had the card too. However, I believe most on board audio does 7.1 these days, no?

Yes but to me the onboard audio is poorer and I can hear a soft buzz (Gigabyte Z370 motherboard with Creative Core3D audio).

Also, this card and daughterboard provides RCA outputs for each channel rather than 3.5mm jacks (2 channels each), allowing me to use better cables.