ASUS Essence STX II 7.1 Review

Is it odd that I find the LME49720 opamps to sound better than the MUSES 8920's?

When I first tried it with the MUSES, I was pretty underwhelmed and found that it didn't sound as good as my memory of an Essence ST.
I then swapped over to the LME49720's and all was cool.

I'm not an audiophile reviewer, so I'll basically describe the difference as more defined and open with better dynamic range if that means anything.
 
I must get around to trying different opamps out, although I don't think my edifier RT1600 speakers are good enough to be able to notice the difference...
 
nightrider1470 said:
for headphones only, is it pointless going for this card over say the DG DGs? My headphones don't need that much powering at all, so makes me wonder.

I have AV receiver for my speakers :)
Click to expand...

The STX is primarily aimed at headphone users and has a very good DAC and headphone amplifier.

As said, what headphones are you using?

If they are good, then the sound quality increase over the DG/DGX is subtle (it usually is) but noticeable in all areas.
 
I had an STX for a number of years and then upgraded to the STX11. There were noticable improvements in all respects. However, I was using it with a high quality passive volume control (Alps Blue Velvet) and a pair of Adam A7X speakers with Sub7 Woofer. I have no doubt that if I had even better monitors the improvements would be even more apparent. I am now selling the STX11 as I upgraded yet again to an external DAC (Audio-gd) and sure enough the sound has improved yet again but of course there is the law of diminishing returns for extra outlay kicking in (though still worth it even with 128bit MP3 files surprisingly).
 
Re: improvement to low bit rate files. Yes that is interesting, as it was not something that I was expecting after upgrading and perhaps not common knowledge. I still think that the STX11 is an excellent audio card and do not regret trying it over the STX (which was originally a shot in the arm for anyone wanting to improve the audio quality from their PC. One manufacturer even tried a valve amp on the motherbaord (AOpen AX4B-533 Tube) to get better quality.
 
I'm still using a standard STX with AKG K702 (modded) and HD650 headphones plus Edifier R1600T speakers and it's enough for me for gaming and movies.

I've tried it against amps & DACs costing several times it's asking price and although it doesn't beat them, it's certainly not embarrassed either.

The balance of quality to price has certainly improved massively over the last few years in the audio market and even entry level sound cards and "some" motherboard audio is capable of good results.

There is always room for improvement though and if that little bit extra is important then it's there for the buying.

There is also a lot of insanely overpriced guff out there too though and telling the difference between something that offers real sound quality improvements and something that looks like it should is a financially precipitous path to tread.

Luckily I don't have enough money to go there :D
 
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The only kind of amp I would use with those is something like an Epiphany O2 or a Schiit Magni and that's mostly so they can be fed from an amp with a low enough impedance.

To perform as designed, some headphones need a high damping factor, which is the ratio of the input impedance of the headphones to the output impedance of the amp. The magic figure for this ratio is 8:1 or just 8. What this does is keep the headphone speaker's voice coils under tight control and the result of poor damping is loose, imprecise and just not very good sounding bass.

The input impedance of the Sony MDR-MA900 is just 12ohms, which is one of the lowest you can get. What makes matters worse is the impedance v frequency graph has a spike in it between 30Hz and 200Hz that rises from 12ohms to about 20ohms. This may not sound much but it's almost doubling it's impedance in that range and means they are sensitive to damping factor.

For the Sonys to perform at their best, you need an amp with an output impedance of no more than 1.5ohms

Output impedances:
Sound Blaster Z = 22ohm
Sound Blaster ZxR = 38ohm
Asus Xonar range = 10ohm
Realtek ALC885/889/892 = 2ohm (board manufacturer may add resistance)
Epiphany O2 = 0.5ohm
Schiit Magni = 0.1ohm
FiiO E10 = 0.5ohm
FiiO E11K = 0.2ohm
FiiO E12A = 0.2ohm
 
rids57 said:
The only kind of amp I would use with those is something like an Epiphany O2 or a Schiit Magni and that's mostly so they can be fed from an amp with a low enough impedance.

To perform as designed, some headphones need a high damping factor, which is the ratio of the input impedance of the headphones to the output impedance of the amp. The magic figure for this ratio is 8:1 or just 8. What this does is keep the headphone speaker's voice coils under tight control and the result of poor damping is loose, imprecise and just not very good sounding bass.

The input impedance of the Sony MDR-MA900 is just 12ohms, which is one of the lowest you can get. What makes matters worse is the impedance v frequency graph has a spike in it between 30Hz and 200Hz that rises from 12ohms to about 20ohms. This may not sound much but it's almost doubling it's impedance in that range and means they are sensitive to damping factor.

For the Sonys to perform at their best, you need an amp with an output impedance of no more than 1.5ohms

Output impedances:
Sound Blaster Z = 22ohm
Sound Blaster ZxR = 38ohm
Asus Xonar range = 10ohm
Realtek ALC885/889/892 = 2ohm (board manufacturer may add resistance)
Epiphany O2 = 0.5ohm
Schiit Magni = 0.1ohm
FiiO E10 = 0.5ohm
FiiO E11K = 0.2ohm
FiiO E12A = 0.2ohm
Click to expand...

Boy you know your audio!

Is low independence always lower quality headphones? I notice a lot of the big named headphones, HD800 etc all need more juice to run.... I really love my MA900 best I have had even comparing to the x2
 
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Low impedance headphones are a relatively recent development, thanks mostly to the rise of the mobile market. In the past most headphones were high impedance. Historically they had to be high impedance because they were being used with hi-fi speaker amplifiers, to which manufacturers often simply added resistance in order to provide a headphone out at reasonable volume. With that in mind, you would routinely be looking at amplifier headphone outputs with impedances in the 50~100ohm range, which forced headphones to have input impedances considerably higher.

High impedance headphones do have a couple of properties that can improve sound quality though, it's not all just a hangover from the past. Having a high impedance allows the headphone to use more turns on the speaker coil windings, which typically means tighter control of the voice coils and cleaner, clearer details. High impedance headphones also require less current to drive and when you combine this with most amplifiers preference for driving higher impedance loads, you end up with less distortion.

Does this mean that low impedance headphones are intrinsically worse than high impedance? No, because it's all realative, it just means that to get the most out of low impedance headphones you have to use an amplifier with a correspondingly lower output impedance. In the case of your Sony MDR-MA900s, you should have no problems at all with any of the very low impedance amps.
 
Does anyone have a review of the opamps for STX II? I can't find anything but advertising, not even anything on the extra opamps shipped with the STX II. The sockets are reportedly fragile (not to mention permanent) so I'm loath to wear them out by experimenting.
 
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