[germanium]

First I want to say up front that I do not own or have access to the Xonar Essense STX or ST card. All my writing here is based on photos, basic layout, & observations of others pertaining to the sound of this card.
The sound as reported here on Headfi pertaining to this card seems that the Lineout sound is less good than the headphone out. Believe it or not that is exactly as I would have expected after seeing the photos of this card. There are a couple reasons for this type sound characteristics the you people are reporting

#1 is the relative high output impedance of the line out (guessing around 600-1000 ohms as is typical for stereo line outs). This causes the lineout to be sensitive to capacitance in the cabling going frome the line out to the preamp. Capacitance should be limited to less than 100 picofarads to prevent audible loss. More than that & instruments such as piano lose some of thier life & sparkle.

#2 is the coupling capacitors used in the lineouts. I believe the Headphone amp bypasses these. The capacitors are there to protect downstream componants typical of hi-fi from the small D.C. offset pesent in the output of the DAC-opamp section. Some equipment is exceptionally sensitive to this & will overheat easily if this is present. The built in headphone amp though is a know quality to the manufacturer & as a result can most likely be safely D.C. coupled without fear of damage.

Electrolytic caps make poor choices for coupling caps as they tend to color the sound & smear the transients again robbing the music of its life. Note that you will likely never see an electrolytic coupling cap in a tube amp as the leakage is quite high & alters the bias to the next stage, a big no no. Even low grade metalized film can fail in this usage (tube amp). I have had this happen!! I replace the low grade metalized films with mil spec film foils at double the volt rating & my bias issues on said tube amp vanished. It even sounded much better.

My understanding at least according to manufacturer literature is that the solid state electrolytics are better for coupling than standard electrolytics at least in transistor gear. I have yet to confirm this though.

Is there any of you guys that know how to trace a circuit that can confirm these assumptions??

 

[ROBSCIX]

I can snap you some high res pics and sen them over to you if you want to look over the circuit closer.

Not all owners suggest that headphone out sound better.
Personally, I use the line outs and think they sound the best. Sepcifications and measurements would also suggest the line out has superior "signal quality".
The HP out: 117dB SNR
The Line out:124dB SNR

Do you suggest any component modifications to upgrade the line outs, such as new caps?

 

[germanium]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif I can snap you some high res pics and sen them over to you if you want to look over the circuit closer. Not all owners suggest that headphone out sound better. Personally, I use the line outs and think they sound the best. Sepcifications and measurements would also suggest the line out has superior "signal quality". The HP out: 117dB SNR The Line out:124dB SNR Do you suggest any component modifications to upgrade the line outs, such as new caps?

Being a multi layer board many traces would be hidden so better photos would be pretty much useless. I was just wondering if anyone has actually traced the circuit could in fact confirm my suspicions listed above. I may get this card some time down the road but moneys tight right now. I already have the Xonar D2 but may upgrade in future.

 

[ROBSCIX]

I will look and see what informaiton I can find you.

 

[germanium]

Quote:

Originally Posted by ROBSCIX /img/forum/go_quote.gif I will look and see what informaiton I can find you.

Thank you Rob

 

[germanium]

bump

 

[germanium]

I was mistaken as far as not being able to see it in a photo as I found this that basically confirms my suspicions that there is no coupling capacitors in the headphone output section but is in the line-out section. I found that most electrolytic coupling caps steal some life out of the music. In some cases this is a blessing but mostly its a curse. Metallized film does much better but won't fit on a sound card. No coupling cap takes the cake though for sound quality in most cases.

welcome to* The Electronic Audio Labs* web magazine

The music that Rob listens to may in fact have some harshness that the coupling caps filter through thier inherant losses & hence sound better to him where as most people seem to prefer the headphone output to feed whatever they use whether headphones or amps as it would sound more open & more articulate especially in the bass & midrange. It may also have significantly better soundstage without the caps.

 

[oqvist]

Well sound is very subjective so I don´t know if you can by charts and such determine what is the best

.How would you do a fair comparison anyway? If you run from line out you better run through a separate amp since the headphone output is getting amplification. And then how do you know the two amps are identically matched. And as mentioned some crazy headphones may benefit from a bit of taming

Still interesting though. Not a perfect comparison but I could try and see what I find running lineout to my amp or external DAC to my amp. Should probably be a better comparision then running headphone out or line out? I don´t have any headphones that doesn´t suck without proper amplification.

 

[germanium]

Quote:

Originally Posted by oqvist /img/forum/go_quote.gif Well sound is very subjective so I don´t know if you can by charts and such determine what is the best .How would you do a fair comparison anyway? If you run from line out you better run through a separate amp since the headphone output is getting amplification. And then how do you know the two amps are identically matched. And as mentioned some crazy headphones may benefit from a bit of taming Still interesting though. Not a perfect comparison but I could try and see what I find running lineout to my amp or external DAC to my amp. Should probably be a better comparision then running headphone out or line out? I don´t have any headphones that doesn´t suck without proper amplification.

Many people claim it sounds better from the headphone amp even when they are driving an amp with it. You cannot drive a headphone from the line out but you can drive either headphones or an amp from the headphone out jack.

 

[oqvist]

How do you connect an external amp to the headphone out jack?

 

[leeperry]

Quote:

Originally Posted by germanium /img/forum/go_quote.gif The music that Rob listens to may in fact have some harshness that the coupling caps filter through thier inherant losses & hence sound better to him where as most people seem to prefer the headphone output to feed whatever they use whether headphones or amps as it would sound more open & more articulate especially in the bass & midrange. It may also have significantly better soundstage without the caps.

the guy I sold my STX to told me that he also doesn't like the sound on the HP output, he says he "can't stand the harsh trebles"....he mostly listen to recent rock stuff.

the Claro Halo has metalized caps I think: HT Omega - Claro halo XT

but it gives terrible IMD figures in RMAA.

 

[germanium]

Quote:

Originally Posted by leeperry /img/forum/go_quote.gif the Claro Halo has metalized caps I think: HT Omega - Claro halo XT but it gives terrible IMD figures in RMAA.

The caps used on that card are solid state electrolytics, Not metalized film.

 

[germanium]

Quote:

Originally Posted by oqvist /img/forum/go_quote.gif How do you connect an external amp to the headphone out jack?

A cable with 1/4" stereo phono plug on one end & RCA plugs on the other end.

 

[FallenAngel]

Aside from the MUCH lower SNR of the headphone output vs the line out, the headphone driver uses TPA6120A2, if you prefer that driver to the opamps in the line driver, that's definitely a credible opinion.

 

[leeperry]

Quote:

Originally Posted by germanium /img/forum/go_quote.gif The caps used on that card are solid state electrolytics, Not metalized film.

Quote:

Panasonic - Metalized Film Capacitor Claro halo uses high grade metalized film capacitors for both opamp and headphone amp IC ports to ensure noise-free ananlog output.

so they're lying?