[ROBSCIX]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif Without getting into further argument, I just want to state that I'm not against soundcard. I only want to see how good it actually is. Well, the only way I would know is by comparison. That's why I've been especially harsh on the STX. Because I've hardly seen any comparisons, especially against higher end offerings. I would like to test it myself, but since the STX isn't available at a retail location and none of my friends have anything better than onboard sound, it's not possible.

I am not arguing, just discussing.

 

[Shahrose]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif Shahrose, you're a prime testing subject! How does your Essence compare to your M^3 with your HD650?

The reason I haven't posted anything about it is because I haven't done a full controlled comparison. The brief one I did revealed the M^3 to be noticeably better as expected. When I get time (in a few weeks perhaps) I'll conduct a more extensive comparison.

I personally think the STX's strength lies mainly in its DAC rather than its amp, but that remains to be seen.

 

[Alydon]

It seems this thread has gotten a bit off-track from what the OP was apparently asking, so allow me to try to get us back on topic.

@Mutsu, you were wondering if you should upgrade your Xonar D2X to the Essence STX or keep the D2X and instead buy an external headphone amp for about the same price (presumably $100-300). To help answer your question I have been doing a comparison for the last 5-6 hours of the following two setups:

1) Xonar HDAV 1.3 -> Corda Opera amp -> DT990's

2) Xonar Essence STX -> DT990's directly through the STX's Headphone out

Now I realize that setup #1 is not the same setup as what you have, but it is as close as I could come. From what I have read, people who have heard both the HDAV 1.3 and the D2X generally agree that the HDAV is the better sounding card for 2-channel music, which doesn't surprise me since the HDAV sounded better to me than the D2 (a PCI version of the D2X) that I used to own.

Additionally, I'm fairly confident that the Corda Opera (which FWIW retailed for $750 right before it was discontinued last Fall) will most likely match or exceed any other headphone amp you can find for $100-$300 (your budget), given that many people on these forums who have much more experience than myself and whose opinion I trust consider the Opera to be one of the best sounding SS headphone amps ever made.

With that in mind... Here are my notes from this comparison:

HDAV+Opera - Mid bass is stronger but it's not as detailed and deepest bass extension is missing. More mid/upper treble presence, but what's there isn't as detailed. Soundstage is taller, but not as deep. You're sitting a couple more rows back from the music than the STX setup. Imaging is a semi-flat curve in front of you. More laid back, Sounds like I'm listening through a slight fog in comparison.

STX + HP out - soundstage deeper but not as tall, imaging improved, more details across the spectrum, clearer, more air, longer decay, instruments are closer to you and have more weight, 3D imaging better, better PRaT, stronger bass impact, more bass extension. Upper-mids/low treble hump, making trumpet bleat slightly. There's a level of realism here that is not present in the HDAV+Opera combo.


As you can probably tell from my notes, IMHO Setup #1, that has a slightly better soundcard than you currently own and has a top-of-the-line headphone amp, still does not sound as good to me as the Essence STX does straight out of it's built-in headphone amp. The two setups were quite close, but listening straight out of the STX sounded to me like it was a minor but easily-recognizable improvement over setup #1 (The HDAV + Opera).

However, it's important to note that like Shahrose said the strength of the STX lies in its DAC section, not it's amp. It's DAC section is what allows it to sound better than setup #1 did. I say this because its built-in amp, although very good sounding in its own right, cannot compare to the sound quality I get when going from STX -> RCA outs -> Corda Opera.

So, you can probably guess what my advice is: Sell the D2X, buy an Essence STX, and when you feel like upgrading again later on down the road then buy an external amp (keeping the STX as a source/DAC).

 

[laobrasuca]

could we talk about numbers? What's the minimum power the HD650 needs to be properly driven and how much power the STX's headphone section deliver @ 300ohms? (Little Dot Mk V provides 187mW @ 300 ohms while Little Dot Mk IV (SE) provides 500mW @ 300 ohms). Is there a maximum (fry out the phones)? That could save a lot of saliva here as we are talking about "be able or not" to drive HD650, and not "the best of the universe" solution.

laobrasuca

edit: we could eventually talk about damping factor.

 

[moonboy403]

I believe the STX's max output is 140mw.

 

[laobrasuca]

And how about a minimum or a maximum power input for this HP? I can't find anywhere any number for minimum or maximum input power for them (or even if these number exist or mean something). By the way, I got a question. I've just seen the specs of the AKG k701 on their website and it is said that it's maximum input power is 200 mW. What does this means? Does it means that if I feed it with 500mW or 1W (e.g., tube amp) it will fry or (less dramatically) it will damage the headphones over the time?

laobrasuca

 

[Reader]

Quote:

Originally Posted by laobrasuca /img/forum/go_quote.gif And how about a minimum or a maximum power input for this HP? I can't find anywhere any number for minimum or maximum input power for them (or even if these number exist or mean something). By the way, I got a question. I've just seen the specs of the AKG k701 on their website and it is said that it's maximum input power is 200 mW. What does this means? Does it means that if I feed it with 500mW or 1W (e.g., tube amp) it will fry or (less dramatically) it will damage the headphones over the time? laobrasuca

Yes if you feed it 1W you will fry it or blow the drivers.

 

[moonboy403]

Quote:

Originally Posted by Reader /img/forum/go_quote.gif Yes if you feed it 1W you will fry it or blow the drivers.

I believe the headphone will only draw as much power as it needs and therefore nothing gets damaged. Don't quote me on it though.

 

[CDBacklash]

It was my impression that that was the amount of power needed to drive the driver too a volume thatll damage it which wouldnt be a problem if you dont turn the volume up very loud.

 

[laobrasuca]

Actually I think that some us here are victime of the "power myth". I'll try to explain from the point of view of electric circuits (please correct me if I'm wrong). Sorry if it will be a bit long, but I'd like detail things here to ask my question, even if most of you already know all this.

There exist 2 kinds of electrical sources: voltage and current sources. Most of (to not say all) headphone amps are voltage sources, i.e., they deliver a constant voltage on the output no metter the impedance of the load (in theory obviously, when the power of the source is infinit). However, the constant output voltage of the amp does not goes directly to the 1/4" (6.5mm) headphone TRS connector, instead such output voltage is split between the load (headphones) and the little circuit so-called volume pot (knob or whatever), which is actually a potentiometer (resistor with variable resistance) in paralel with the charge (the headphone in this precise case). The goal of using such variable resistor in pararel to the headphone is to directly control the voltage, thus the current (or conversely, depending on the pot design) going to the headphones or, in other words, control the power delivered to the headphones (metter the power of the amp): when we turn the volume pot toward the max vol the resistance of the knob increases such that less current will pass trough it, thus more power going to the headphone (at max vol all amp's power goes to the headphone). So, FINALLY it comes to my question: do you really use the max vol of your 500mW tube amp or you have headache before reaching it? xD See what I mean? Do we really need a 500mW amp if we will put at max 200mW to the headphone (at the risk to damage the headphone's circuit)? Why people keep saying that 140mW or even 100mW is not enough to drive the k701? That's my point, and maybe it's a myth. Of coarse, it always depends on the headphone's impedance. Or am I getting all wrong, and the problem of the STX is not the power it can deliver, but the quality of the amplified signal? In such case, wouldn't it be more simple and costless to replace the two stock 2114 by LM4562 instead of buying a whole new AMP? And here you would answer the question of this topic!

lao

 

[laobrasuca]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif I believe the headphone will only draw as much power as it needs and therefore nothing gets damaged. Don't quote me on it though.

I really don't see how

 

[moonboy403]

Quote:

Originally Posted by laobrasuca /img/forum/go_quote.gif Actually I think that some us here are victime of the "power myth". I'll try to explain from the point of view of electric circuits (please correct me if I'm wrong). Sorry if it will be a bit long, but I'd like detail things here to ask my question, even if most of you already know all this. There exist 2 kinds of electrical sources: voltage and current sources. Most of (to not say all) headphone amps are voltage sources, i.e., they deliver a constant voltage on the output no metter the impedance of the load (in theory obviously, when the power of the source is infinit). However, the constant output voltage of the amp does not goes directly to the 1/4" (6.5mm) headphone TRS connector, instead such output voltage is split between the load (headphones) and the little circuit so-called volume pot (knob or whatever), which is actually a potentiometer (resistor with variable resistance) in paralel with the charge (the headphone in this precise case). The goal of using such variable resistor in pararel to the headphone is to directly control the voltage, thus the current (or conversely, depending on the pot design) going to the headphones or, in other words, control the power delivered to the headphones (metter the power of the amp): when we turn the volume pot toward the max vol the resistance of the knob increases such that less current will pass trough it, thus more power going to the headphone (at max vol all amp's power goes to the headphone). So, FINALLY it comes to my question: do you really use the max vol of your 500mW tube amp or you have headache before reaching it? xD See what I mean? Do we really need a 500mW amp if we will put at max 200mW to the headphone (at the risk to damage the headphone's circuit)? Why people keep saying that 140mW or even 100mW is not enough to drive the k701? That's my point, and maybe it's a myth. Of coarse, it always depends on the headphone's impedance. Or am I getting all wrong, and the problem of the STX is not the power it can deliver, but the quality of the amplified signal? In such case, wouldn't it be more simple and costless to replace the two stock 2114 by LM4562 instead of buying a whole new AMP? And here you would answer the question of this topic! lao

I asked a fellow head-fier who's very knowledgeable about this subject and here are his responses:

"An amplifier rated at 700mW power means this is the maximum power it can produce and deliver into the headphones. The volume control adjusts the voltage amplified by the amplifier and power delivered into the headphone (power is voltage squared divided by load impedance). At normal listening levels you are listening to only a few milliwatts to perhaps tens of milliwatts. Now if you turned the volume control to maximum causing the amplifier to generate and deliver its maximum power ability, then yes you would be damaging the headphones because it is higher than the 200mW they can accept. The speaker drivers would either be bottoming, reaching their movement limits, or the voice coil would overheat and burn out."

 

[moonboy403]

Here's another question I asked: So how does a it differs when a headphone is powering by say a soundcard that can provide 140mw at 32ohms and a desktop amp that can provideo 1watt at 32 ohms? How does one amp perform better than another when all we need is a few mw?

Here's the response: "This is the age old question! 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.

Computers are very RFI noisy environments due to all the digital clocks and microprocessors. This RFI affects the amplifiers operation and sound quality produced. Soundcards are normally designed for mass production using low cost components, many integrated circuits for the audio amplification which don't necessarily sound good, etc.

I have no doubt a dedicated outboard amplifier of the same power as the soundcard would sound better.

I prefer good tube amplifiers. From my experience for both hi-fi loudspeakers and headphones, tubes sound the most clear, dynamic, great inner resolution and tonality, while sounding fun and involving long term."

 

[laobrasuca]

Quote:

Originally Posted by moonboy403 /img/forum/go_quote.gif Here's another question I asked: So how does a it differs when a headphone is powering by say a soundcard that can provide 140mw at 32ohms and a desktop amp that can provideo 1watt at 32 ohms? How does one amp perform better than another when all we need is a few mw? Here's the response: "This is the age old question! 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. Computers are very RFI noisy environments due to all the digital clocks and microprocessors. This RFI affects the amplifiers operation and sound quality produced. Soundcards are normally designed for mass production using low cost components, many integrated circuits for the audio amplification which don't necessarily sound good, etc. I have no doubt a dedicated outboard amplifier of the same power as the soundcard would sound better. I prefer good tube amplifiers. From my experience for both hi-fi loudspeakers and headphones, tubes sound the most clear, dynamic, great inner resolution and tonality, while sounding fun and involving long term."

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...

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)?

Could you ask this one more question to this same fellow head-fier: what do you think about an STX upgraded compared to an (no so expensive, like < 300 USD) outboard amp? I think this is the central subject of this topic.

lao

 

[moonboy403]

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... 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)? Could you ask this one more question to this same fellow head-fier: what do you think about an STX upgraded compared to an (no so expensive, like < 300 USD) outboard amp? I think this is the central subject of this topic. lao

I think the answer's included in the second quote: "I have no doubt a dedicated outboard amplifier of the same power as the soundcard would sound better."

I asked him about the STX and here is his response: "It looks like they tried to do a good job on this sound card, using TI chips, Nichicon audio-grade capacitors, and shielding.

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
2. Maximum output is 2Vrms. This might be a problem with higher impedance headphones, limiting the maximum power delivered.

You would have to hear this unit to see if it sounds good. I still believe a dedicated outboard headphone amp using either discrete transistors or tubes will sound better, but it will cost more $$$."