[dex85]

you're right, given we're both talking about Audacity decrease of volume. well, you should have quoted it earlier to be clear about what you were responding to.

 

[germanium]

The gain of the headphone amp in the control panel is in fact only a digital volume control. the gain of the headphone amp is fixed in hardware & not adjustable except by dropping the approprate bits in software. there are no gain control switches of any kind in the board whether they be transistor or solinoid. Note that there is no solinoid switching sounds during gain changes, only during output or input changes. There is also no gain control in the pinout of the amp itself as I have looked that over in the manufacturers documentation of that amp. So contrary to what Robscix says (not denegrating him here as he is usually right on in what he says) it is entirely reasonable that there is no difference in sound quality whether using Audacity or the soundcard control panel gain setting for the headphone amp as both adjust the gain by reducing the volume by 1 or more bits to get the correct volume fore that setting.

 

[hoglum]

OK that was a little over my head.. so this is probably a stupid question, but are you saying that reducing the gain could actually reduce sound quality too?

 

[germanium]

Quote:

OK that was a little over my head.. so this is probably a stupid question, but are you saying that reducing the gain could actually reduce sound quality too?

Any gain reduction should not noticably reduce quality except in cases of really wide dynamic range music & that only if you are set to 16 bit bit depth. You will not notice any degradation at all if set for 24 bit output.

 

[dex85]

interesting, thanks for the very insightful explanation, as always
Quote:

The gain of the headphone amp in the control panel is in fact only a digital volume control. the gain of the headphone amp is fixed in hardware & not adjustable except by dropping the approprate bits in software. there are no gain control switches of any kind in the board whether they be transistor or solinoid. Note that there is no solinoid switching sounds during gain changes, only during output or input changes. There is also no gain control in the pinout of the amp itself as I have looked that over in the manufacturers documentation of that amp. So contrary to what Robscix says (not denegrating him here as he is usually right on in what he says) it is entirely reasonable that there is no difference in sound quality whether using Audacity or the soundcard control panel gain setting for the headphone amp as both adjust the gain by reducing the volume by 1 or more bits to get the correct volume fore that setting.

 

[germanium]

Note if you look at the HT Claro Halo soundcard they do in fact provide a hardware solution to adjust the gain of the amp in the form of jumper switches near the back of the card. With that card one must open the case & in some cases even remove the card to change the gain setting of the amp. The same could be done with transistors or solinoids however there are no transistors near the headphone amp & there are no solinoid noises during gain changes, nor are there any jumper switches which leaves only digitally reducing gain in software on the Essense STX or ST cards. The HT Claro Halo uses the same headphone amp chip. The DAC chip & opamps are not as good as the Essence DAC & opamps though.
 
Not having a hardware solution though is not nessessarily bad as if the hardware solution is not handled properly it can result in poor performance of the amp itself especially with current feedback type amps such as the amp on the cards mentioned.Not having a harware solution allows Asus to optimize the circuit path to be as short as possible which is a very good thing with these particular headphone amps as they are sensitive to the extreme to poor circuit layout & can go unstable in a heartbeat if not properly done.
 
Note that these amps are extremely fast at any gain level. Thier performance is not affected at all by gain changes & the amps are flat to 10MHz at all gain settings unlike voltage feedback amps which loose a substatial amount of performance at high gain levels. One of the problems with current feedback amps has been poor linearity in the past but that seems to have been solved with these amps given thier excellent S/N ratio & very low distortion.

 

[InFn-0]

If you cannot find a difference between the low gain and high gain then something surely is wrong. Have a cup of tea and chill

 

[germanium]

 
Quote:

If you cannot find a difference between the low gain and high gain then something surely is wrong. Have a cup of tea and chill

The only difference is with high impedance headphones you now have sufficient drive to get the to the proper listening volume. If you can in fact drive them to the same volume at a lower gain setting then the sound is in fact identical. Any difference you think you hear is actually placebo effect. You believe there is a difference even though none in fact exsists. No matter what the headphone amp gain is set to, if the volume is matched the signal is represented by the same number of bits on the Asus Essense cards
 

 

[hoglum]

Quote:

 

The only difference is with high impedance headphones you now have sufficient drive to get the to the proper listening volume. If you can in fact drive them to the same volume at a lower gain setting then the sound is in fact identical. Any difference you think you hear is actually placebo effect. You believe there is a difference even though none in fact exsists. No matter what the headphone amp gain is set to, if the volume is matched the signal is represented by the same number of bits on the Asus Essense cards
 

So in other words, there's no point in using any headphone amp if you can get the volume loud enough without one? Which would mean that amps only increase volume? Or does this only apply to the essence card?

 

[shimm]

Xonar Essence ST prefers 100-300 ohms phone impedance. In this range distortions and output power are balanced. Sorry, only in russian:
 

Spoiler

 

 

[germanium]

Quote:

So in other words, there's no point in using any headphone amp if you can get the volume loud enough without one? Which would mean that amps only increase volume? Or does this only apply to the essence card?

What I'm saying only applies to the Essense cards onboard amp.There can be differences in amps outside of the Essense card but when used in conjunction with the Essense cards you are limited by the sound of the source which actually in the case of the Essence cards they are very good. This is especially true if the ouput coupling caps are removed & wire put in thier place on the line out. Any coloration then would come from the external amp not through any limitation of the card as I have found the card with these minor changes to be free of any coloration of its own & that is with the stock opamps. There is real differences in the coloration of external amps. Some being quite colored & some not at all The essense amps though are truely not colored an any way. The lineout stock is somewhat but not the headphone amp. With the output coupling caps on the line out there is some losses of fidelity but pretty minimal.
 
My modified Onkyo P304 preamp headphone amp has been modified by me & is also free of any coloration after the mods & sounds just like the headphone out on the Essense STX driven from the D.C. coupled Lineout. Note the the p304's headphone amp is also D.C. coupled after my mods & so is the headphone amp on the Essense cards stock.
 

 

[Dalamar]

Quote:

So in other words, there's no point in using any headphone amp if you can get the volume loud enough without one?

You've just learned what 95% of head-fi ignores in favor of bigger, needlessly more expensive toys. An amp is an amp, if you're able to squeeze out enough power for your listening volume without distortion, you don't need an amp.
 
I imagine HD650s may need an amp for low-power mp3 player use, but most likely not for a soundcard.
 
It sounds to me like you don't like the Sennheiser house sound.

 

[hoglum]

Thanks for the insight guys.

I'm returning the card today, so I guess I'll get the final verdict if and when any defect is found (I'm surprised if there isn't any). There seems to be a lot of opinions/beliefs about whether (phone) amps make any difference and how much.. I've never listened to a high-end HP amp but I know it can make a huge difference with regular speakers. I'm curious to find out the truth.
 
Quote:

It sounds to me like you don't like the Sennheiser house sound.

I'm not sure it's so much about what sound I like as it is about what sound I'm used to. I always upped the bass and treble on my audigy card, so I'm used to that sound. The unequalized sound of the essence card naturally lacks in bass and treble in comparison. I mean, you could get used to anything. If you for example cut all the frequencies below 100hz and listen to that for a while, you'll get used to it and it starts to sound "normal". So that's why I'm looking for the sound that's closest to the recordning - the way it was intended to sound - rather than what suits me best.