[jenneth]

Quote:

Originally Posted by laobrasuca /img/forum/go_quote.gif About the quality of construction, components.... Well, asus seems to make a great effort on producing a soundcard of same quality (or better) than many good/excellent amp out there. Using the EMI shield it would also reduce a lot the RFI (note that the shield also protects the amp part, not only the DAC). It is so well build that everyone in here seems to agree to say that the DAC of STX is excellent. Then, I re-ask my question: wouldn't it be more simple and less costly to replace the two stock 2114 by LM4562 instead of buying a whole new AMP? Or an outboard amp is really the way to go (based on the experience of those who really listened to an upgraded version of STX and could compare to good outboard amps)?

The answer of this question will be different for each person you asked, as it comes down to the question of value. To some people, spending anything over $50 on audio related stuff is consider 'insane', while the said person is willing to spend $5000 on imported Italian calf leather couch. The STX is an excellent sound card, it has satisfied many people, and let's just leave it at that.

 

[laobrasuca]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif ...Two immediate observations: 1. They don't specify the output impedance. Headphone amps should have 2 selectable output impedances: one low, the other higher around 120 ohms per the IEC spec. Some headphones (Sennheiser HD650, beyerdynamics, AKG K601s for example) sound better when driven by a higher source impedance..."

3 sets actually. But well, I got the point.

@jenneth: Y, you may be right. I would expect that a 5000$ headphone amp (if there exists one at this price) will sound WAY WAY WAY better than this 200$ combo, otherwise it would be a really marketing fake stuff!

Anyway, i think that we can conlude this saying that if you have more than, say, 500 USD you buy an outboard amp, if not, stick with the STX combo solution and upgrade the stock 2114 to better ones.

I'm not the owner of this topic, otherwise I would say: topic closed

 

[Uncle Erik]

Quote:

Originally Posted by laobrasuca /img/forum/go_quote.gif ok, very nice, thank you for your interest and research on this. About the power story, the fellow head-fier confirmed what I said. So, power myth down. Those who say that STX can not power/drive a headphone (even of high impedance) please do not insist in this point anymore... lao

I think you misunderstand both power and impedance.

There is a weird equivalency out there where it seems as if people who think a product sounds good automatically assume that that is the best possible sound and that other products - especially ones that cost more - are some sort of ripoff. This has been slugged out with portable amps any number of times but now seems to be creeping into soundcards.

The impressions you read are typically from people who went from an iPod to a soundcard. Of course it sounds better. But does it sound better than the best available? No.

Power is important. To get 140mW out of the card, the input has to be at maximum (e.g. a peak in the music) while the volume is at maximum. Otherwise, it'll loaf along at, say, 25mW. If you have an amp with a maximum output of 500mW, you won't get 500mW unless you have the same circumstances. It will, however, loaf along at 150mW.

When you have a big driver, like that in a Sennheiser, you need enough power to adequately move it back and forth.

Something putting out 25mW is going to leave the Senn sounding muddy, veiled and two dimensional. For someone who hasn't heard a Sennheiser with adequate power, that might sound like the best thing they've ever heard. For someone who has heard a Sennheiser with adequate power, it sounds like crap. Having built and listened to lots of amps, Sennheisers don't really seem to open up and sound good until you plug them into something with about 500mW or more. There's more to amplification than that, but portables, soundcards, et al., just don't cut it.

If you want to argue anecdotes and testimonials, head over to Summit-Fi and ask there. The participants there have four, five or six figure disposable incomes. Contrary to popular belief, even rich folks tey to spend money wisely. If it were possible to get equivalency for $200, they probably would. But instead, you'll see people with a variety of dedicated desktop style amps. Ask yourself why that is and leave the class warfare out.

If you want to find out on the cheap by yourself, go pick up a $20 receiver at Goodwill and plug into that. They're not the best amps, but you will get sufficient output power at 10% the cost of the soundcard. You might even get a phono stage, which would be worth the $20 alone.

As for impedance, very generally speaking, high impedance headphones are easier to drive than low impedance ones. If you don't believe me, Google for information on driving Apogee ribbons. One of their models had an impedance of 1.2 Ohms. They have a reputation for melting (and I mean that literally) lesser amps. If low impedances were easy to drive that would not be the case.

The trick of impedance is matching an amp's output impedance to the impedance of the headphones. The closer the impedances match, the more efficiently power transfers from the amp to the headphones. If there is an impedance mismatch, then you lose power. There is a formula where you can work out power loss from a mismatch.

Unless you're really in need of the other features on a soundcard (for games or whatever) then you should consider a full-sized amp to drive Sennheisers. Rolling opamps and hooking up an external power supply are like putting a gigantic wing on an economy car. You might get some performance benefit, but more often than not, you'd be a lot better off buying a used sports car that's engineered to perform rather than a cobbling together of tweaks.

If money is tight, that's OK. Like I mentioned earlier, a used receiver can work fine. Maybe you can find one for free. If you can spend more, there are excellent low cost desktop amps. If you want to build one - and really get value for your money - check in at the DIY Forum. The DIY crowd will help you through your first build and point you in the right direction.

But don't fall for this weird equivalency thing. Again, don't take my word for it. Go find out for yourself. Get a cheap receiver and listen. Go to a meet and listen. Go listen to a real amp and you will immediately hear the difference.

 

[Reader]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Power is important. To get 140mW out of the card, the input has to be at maximum (e.g. a peak in the music) while the volume is at maximum. Otherwise, it'll loaf along at, say, 25mW. If you have an amp with a maximum output of 500mW, you won't get 500mW unless you have the same circumstances. It will, however, loaf along at 150mW. When you have a big driver, like that in a Sennheiser, you need enough power to adequately move it back and forth. Something putting out 25mW is going to leave the Senn sounding muddy, veiled and two dimensional. For someone who hasn't heard a Sennheiser with adequate power, that might sound like the best thing they've ever heard. For someone who has heard a Sennheiser with adequate power, it sounds like crap. Having built and listened to lots of amps, Sennheisers don't really seem to open up and sound good until you plug them into something with about 500mW or more. There's more to amplification than that, but portables, soundcards, et al., just don't cut it.

Whole lot of non sense, your (or Mine) HD 650 do not have a "ultra smart AI and magic circuit" that will know which amp it's plugged into, when it pluged into my prehead it's not going go "I am in prehead now, I will draw 500mw, but instead of making it really loud and blow the driver I will use the extra power to make it sound better!!" Or "I am in STX now, I will draw 30mW to get the same Vol but it just won't sound as good."

At same wattage, the same headphone it will have the same vol, 500mw likely will kill it or make you deaf. Headphone amp is not about pump out more wattage, it's about how well it outputs at certain wattage.

 

[moonboy403]

Quote:

Originally Posted by Reader /img/forum/go_quote.gif Whole lot of non sense, your (or Mine) HD 650 do not have a "ultra smart AI and magic circuit" that will know which amp it's plugged into, when it pluged into my prehead it's not going go "I am in prehead now, I will draw 500mw, but instead of making it really loud and blow the driver I will use the extra power to make it sound better!!" Or "I am in STX now, I will draw 30mW to get the same Vol but it just won't sound as good." At same wattage, the same headphone it will have the same vol, 500mw likely will kill it or make you deaf. Headphone amp is not about pump out more wattage, it's about how well it outputs at certain wattage.

Which brings back to the quote I gave earlier: "There's more to amplifier sound quality than just power. It has to do with the type of both audio and power supply circuit designs, tube or transistor, class A or AB or D, discrete or integrated circuit, quality of components used, how well the amplifier reacts to the back EMF from the headphone transducers, etc. "

 

[Reader]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif Which brings back to the quote I gave earlier: "There's more to amplifier sound quality than just power. It has to do with the type of both audio and power supply circuit designs, tube or transistor, class A or AB or D, discrete or integrated circuit, quality of components used, how well the amplifier reacts to the back EMF from the headphone transducers, etc. "

Indeed, it's about quality not raw power.

 

[laobrasuca]

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif I think you misunderstand both power and impedance. There is a weird equivalency out there where it seems as if people who think a product sounds good automatically assume that that is the best possible sound and that other products - especially ones that cost more - are some sort of ripoff. This has been slugged out with portable amps any number of times but now seems to be creeping into soundcards. The impressions you read are typically from people who went from an iPod to a soundcard. Of course it sounds better. But does it sound better than the best available? No.

I got to admit that 90% (or even more) of those who listen to music are happy with their fashion portable mp3 player, stok earphones and low encoding quality audio files. "Spend 100$ in a headphone, are you crazy?" they would say. Not everyone understand or care about the quality of the components and the design/build of the audio equipment, the power it can deliver, so on and so fourth, as long as they can hear to something like what their 150$ LCD TV set output as sound. But it's not my case and it's not the case of those who come ask questions here in this forum. So when you say "The impressions you read are typically from people who went from an iPod to a soundcard." is a bit depreciative. But anyway, have you already tested a STX upgraded? You know, in other post a fellow criticized this card so badly before testing one that his reaction after buying one and upgrading it was really funny given the context: "[...]I'm stunned

[...] wider soundstage, no saturation audible whatsoever, very very very clean and chirurgical sound[...]" There's some king of prejudice/inertia when it comes to juge a soundcard and comparing it to an outboard desktop solution, like: "oh, come on, another soundcard" That's the very exact reason why asus ship along with the card a fashioned piece of paper with their test results, trying to show that it can drive any headphone and deliver a SQ equivalent to outboard solutions costing 2, 3 or 4 times the price. It is obvious, natural, elementar, trivial that it will not be the BEST solution ever, come on, we are not talking about this. A combo like DAC1+MkIVSE will not be the BEST solution ever neither, even costing 5 times or more the price of the STX. However, how the "best" opamp STX upgrade would sound compared this combo? That's the aim of this topic! How much money does one have to put into an outboard amp to feel the difference on SQ? 50$, 150$, 300$, 500$, 1000$, 5000$? Worse than the opinion of "people who went from an iPod to a soundcard" is the opinion of someone who have never tried it. Maybe this card is breaking paradigms, why not?

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Power is important. To get 140mW out of the card, the input has to be at maximum (e.g. a peak in the music) while the volume is at maximum. Otherwise, it'll loaf along at, say, 25mW. If you have an amp with a maximum output of 500mW, you won't get 500mW unless you have the same circumstances. It will, however, loaf along at 150mW.

Maybe it's not a good idea to make an amp work at its maximum capability for a long duration (but i'm not so sure about, since if the power is not going to the headphone, it is going to the volume pot and the amp end up delivering its entire power anyway). But, well, we are lacking of official numbers here. I quote moonboy403:

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif I asked a fellow head-fier who's very knowledgeable about this subject and here are his responses: "[...]At normal listening levels you are listening to only a few milliwatts to perhaps tens of milliwatts.[...]"

"few milliwatts to perhaps tens of milliwatts" is far less than 140mW or even 25mW. That's why I say power is (possibly) not a problem with the STX.

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif When you have a big driver, like that in a Sennheiser, you need enough power to adequately move it back and forth. Something putting out 25mW is going to leave the Senn sounding muddy, veiled and two dimensional. For someone who hasn't heard a Sennheiser with adequate power, that might sound like the best thing they've ever heard. For someone who has heard a Sennheiser with adequate power, it sounds like crap. Having built and listened to lots of amps, Sennheisers don't really seem to open up and sound good until you plug them into something with about 500mW or more. There's more to amplification than that, but portables, soundcards, et al., just don't cut it.

Do you really have the numbers? For example, for the HD650, what's the max input power? 25mW corresponds to what? pleasant volume level or headache? Have you already measured and compared input power vs decibels produced by the headphones of a given impedance?

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif As for impedance, very generally speaking, high impedance headphones are easier to drive than low impedance ones.

Is it me, or you are in a contradictory position here, compared to what i've just quoted above? After all, Senns have high impedance.

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif [...]One of their models had an impedance of 1.2 Ohms. They have a reputation for melting (and I mean that literally) lesser amps. If low impedances were easy to drive that would not be the case.[...]

Indeed, low impedance suck more current for the same voltage, thus more power (and not in a linear way, but power 2). If the AC-DC transform stage is not able to carry such power it will melt indeed (too much heat due to the greater current than expected). That's why STX default gain is the low one. Low gain will not damage no one, even if i put a 1.2ohm device on its output. In the worst case it will not drive the headphone correctly, but you have 2 more gain set to adequate it to your headphone output. But what is good with the STX is that if you have a good PSU (and you better do if you want your pc to run stable and safe) it will prevent everyone to burn, so asus do not worry about design an dedicated power unit to it and can save extra costs.

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif The trick of impedance is matching an amp's output impedance to the impedance of the headphones. The closer the impedances match, the more efficiently power transfers from the amp to the headphones. If there is an impedance mismatch, then you lose power. There is a formula where you can work out power loss from a mismatch.

Impedance matching is an essential thing for, for example, transmission lines, or electric motors, where you don't what lose any of the available power, avoiding current reflection. But in audio application power transfer is not the way to go, instead voltage transfer is, the so-called impedance bridging. Any experimented person will say to you that it is more important to drive the headphone accurately/precisely than transfer all power available to it. Once again quote moonboy403:

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif [...]2. Maximum output is 2Vrms. This might be a problem with higher impedance headphones[...]

meaning, voltage transfer is more important than power transfer. And other concept more important than power transfer is the damping factor. In other words, driving quality is more importante than brute force power transfer. So, when you say "I think you misunderstand both power and impedance." it's maybe the opposite.

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Unless you're really in need of the other features on a soundcard (for games or whatever) then you should consider a full-sized amp to drive Sennheisers. Rolling opamps and hooking up an external power supply are like putting a gigantic wing on an economy car. You might get some performance benefit, but more often than not, you'd be a lot better off buying a used sports car that's engineered to perform rather than a cobbling together of tweaks.

It would be true if STX had a junk amp section. Instead it has a high fidelity TI 6120A2 HP amp surrounded but high quality caps. It seems that the major problem of the STX amp section are the two 2114 used by default. Then, I ask again, who much money to I need to put in a desktop amp to improve the SQ of an STX opamp upgraded (given that the opamp upgrade cost almost nothing)?

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif Contrary to popular belief, even rich folks tey to spend money wisely. If it were possible to get equivalency for $200, they probably would.

I'm not so sure about it, not if the 200$ device is a soundcard (prejudice...)

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif But instead, you'll see people with a variety of dedicated desktop style amps. Ask yourself why that is and leave the class warfare out.

It can turn to paranoia the seek for perfect sound.

Quote:

Originally Posted by Uncle Erik /img/forum/go_quote.gif If you want to find out on the cheap by yourself, go pick up a $20 receiver at Goodwill and plug into that. They're not the best amps, but you will get sufficient output power at 10% the cost of the soundcard. You might even get a phono stage, which would be worth the $20 alone.[...] If money is tight, that's OK. Like I mentioned earlier, a used receiver can work fine. Maybe you can find one for free. If you can spend more, there are excellent low cost desktop amps. If you want to build one - and really get value for your money - check in at the DIY Forum. The DIY crowd will help you through your first build and point you in the right direction. But don't fall for this weird equivalency thing. Again, don't take my word for it. Go find out for yourself. Get a cheap receiver and listen. Go to a meet and listen. Go listen to a real amp and you will immediately hear the difference.

Thank you for your advices, I will not neglect them.

It would be nice if you could test a STX upgraded and come report your impressions.

lao

 

[laobrasuca]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif Which brings back to the quote I gave earlier: "There's more to amplifier sound quality than just power. It has to do with the type of both audio and power supply circuit designs, tube or transistor, class A or AB or D, discrete or integrated circuit, quality of components used, how well the amplifier reacts to the back EMF from the headphone transducers, etc. "

BTW, to which class thus the amp section of the STX belongs to? AB?

 

[laobrasuca]

Quote:

Originally Posted by Reader /img/forum/go_quote.gif Whole lot of non sense, your (or Mine) HD 650 do not have a "ultra smart AI and magic circuit" that will know which amp it's plugged into, when it pluged into my prehead it's not going go "I am in prehead now, I will draw 500mw, but instead of making it really loud and blow the driver I will use the extra power to make it sound better!!" Or "I am in STX now, I will draw 30mW to get the same Vol but it just won't sound as good."

Well, I would not say that it's complete non sense, since the 3 presets STX has for headphone gain control is meant to this. OFC, its not a "ultra smart AI and magic circuit" who decide it, but the user.

Quote:

Originally Posted by Reader /img/forum/go_quote.gif At same wattage, the same headphone it will have the same vol, 500mw likely will kill it or make you deaf. Headphone amp is not about pump out more wattage, it's about how well it outputs at certain wattage.

I would like to see an input power [mW] versus headphone decibels sound power [dB] (>85dB for hours would definitively damage your hearing) curve for a given headphone (K701 and HD650, why not?).

lao

 

[moonboy403]

Quote:

Originally Posted by laobrasuca /img/forum/go_quote.gif It would be true if STX had a junk amp section. Instead it has a high fidelity TI 6120A2 HP amp surrounded but high quality caps. It seems that the major problem of the STX amp section are the two 2114 used by default. Then, I ask again, who much money to I need to put in a desktop amp to improve the SQ of an STX opamp upgraded (given that the opamp upgrade cost almost nothing)?

"The MKV is clearly better. I've had it. I consider the TI internal amp in the big picture of things a low-end amp. It's not crap, but it's not stellar either." - Chinesekiwi

 

[Reader]

Quote:

Originally Posted by laobrasuca /img/forum/go_quote.gif Well, I would not say that it's complete non sense, since the 3 presets STX has for headphone gain control is meant to this. OFC, its not a "ultra smart AI and magic circuit" who decide it, but the user.

I was talking about HD 650 not STX

 

[genclaymore]

If It was me I would go with whatever you can afford and if your happy with your existing onboard or sound card if you go the headphone amp route.

 

[laobrasuca]

Quote:

Originally Posted by Reader /img/forum/go_quote.gif I was talking about HD 650 not STX

y I know

 

[laobrasuca]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif "The MKV is clearly better. I've had it. I consider the TI internal amp in the big picture of things a low-end amp. It's not crap, but it's not stellar either." - Chinesekiwi

humm, ok. 300$ investment then. Well, do not have 500$ now, so, maybe in the future I buy an outboard amp...

and if we talk about the dac section? compass > STX (> zero)? or it's not so noticeable?

thx, lao

edit: I mean, if the way is to by a dedicated amp in the future, the ZERO could come back to the contest if the DAC section is solid and provide QS quite as good as the stx and compass.

 

[laobrasuca]

Quote:

Originally Posted by genclaymore /img/forum/go_quote.gif If It was me I would go with whatever you can afford and if your happy with your existing onboard or sound card if you go the headphone amp route.

y, you right!