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DO i need an external Amp

post #1 of 16
9/18/11 at 10:44pm
Thread Starter 

Hi guys i have a soundcard Asus xonar xense(those have a built-in amp) can it drive correctly my Bayerdynamic T1 ? or should i buy an amp with DAC 

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post #2 of 16
9/18/11 at 11:33pm

I'd say you need an amp to get your money's worth out of the t1.

 

DAC not necessary

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post #3 of 16
9/18/11 at 11:36pm
Thread Starter 

thanks man :) but will the AMP improve the sound quality or is this only to give up louder sound?

 

and how i should plug the AMP on my pc since all amp have RCA plug?


Edited by bayerty - 9/19/11 at 12:34am
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post #4 of 16
9/19/11 at 7:15am

The T1 is a 600 Ohm, rather demanding headphone. Using an amp will improve sound quality since the dynamic range will increase. 

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post #5 of 16
9/19/11 at 11:01am
I'm not sure about the Xense, but it only puts out 2V rms according to Asus. That's good for about 105 dB SPL max output according to InnerFidelity measurement of 0.346 V rms needed for 90 dB SPL. If you listen to music with a wider dynamic range, you could probably use some more power.

It's possible that the Xense amp is not that good when outputting high volumes or has some issues, or otherwise that a separate amp would produce a higher quality sound. I wouldn't necessarily expect something to be significantly better than the Xense output aside from extra power, but it may well be. Certainly if you have a T1, you may as well try something.

You would connect an external amp to the line out of the Xense through a 1/4" M TRS to Stereo M RCA connector. Something like this:
http://www.musiciansfriend.com/accessories/hosa-stereo-1-4--2-rca

Nevermind the 1/4" out is the headphone out obviously. You use the bundled audio splitter cable (for 7.1 out) and just use the green (front stereo out) output. You'd need a 1/8" (3.5mm) M TRS to Stereo M RCA connector, like one of these that are male to male:
http://www.monoprice.com/products/subdepartment.asp?c_id=102&cp_id=10218#1021804
Edited by mikeaj - 9/19/11 at 11:07am
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post #6 of 16
9/19/11 at 12:35pm

it appears to be the same amp in my asus essence st, or similar output at 2v rms...

 

I bet Asus overrates their amps.  My 600 ohm T1 cannot be properly powered.  The amp easily drives the t1 to loud enough volumes and "okay" quality.  That being said, my t1 sounds sluggish on my asus.  Sluggish to the point where I'd say my hd595 (a meager, but good 100 dollar headphone) is on par.

 

I recommend the Concerto amongst amps that I have tried (Burson 160, Xm6, Lyr).  It's no longer sold.  There are a few used ones for sale, but if you got the money I'd wait for one of Jan's upcoming new amps.  

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post #7 of 16
9/19/11 at 2:07pm
Thread Starter 

can i just plug the RCA in the amp and plug a RCA to 6.25mm jack adapter and plug that in my 6.25mm jack on the back of my sound card? 

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post #8 of 16
9/19/11 at 2:16pm

Yes, but if you got a dac/amp combo then I would use the spdif out.

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post #9 of 16
9/19/11 at 2:21pm
Thread Starter 

yea obviously with a DAC it makes thing more easy but do i really need a DAC?

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post #10 of 16
9/19/11 at 2:28pm
Quote:
Originally Posted by rrahman View Post

it appears to be the same amp in my asus essence st, or similar output at 2v rms...

 

I bet Asus overrates their amps.  My 600 ohm T1 cannot be properly powered.  The amp easily drives the t1 to loud enough volumes and "okay" quality.  That being said, my t1 sounds sluggish on my asus.  Sluggish to the point where I'd say my hd595 (a meager, but good 100 dollar headphone) is on par.

 

 


No, ST/STX output is 7V rms (about 11 dB higher than 2V rms) on the highest setting, as measured by Stereophile:
http://www.stereophile.com/content/asus-xonar-essence-ststx-soundcards-measurements

Not sure what you mean by "overrated" but the full-scale tests into 600 ohms shows IMD products below -110 dB, with THD pretty much in the noise floor or about as low. I kind of wonder about the ST vs. STX differences. Maybe it has to do with a different computer being used for each test, so maybe with a certain computer, you could get significantly worse performance than the STX tested there. Or maybe (would seem bizarre though) the ST is just significantly worse?

Not to be too presumptuous, but maybe you prefer a less flat presentation with the T1? Or your ST has problems in your computer.

edit: unless you're looking for some special DAC features and indicators, I don't think it would be smart (if you're aiming for a transparent presentation) to ditch the sound card's DAC. These well-tested mass-produced DACs in higher-end sound cards tend to have far fewer inaccuracies than most audiophile gear.
Edited by mikeaj - 9/19/11 at 2:31pm
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post #11 of 16
9/19/11 at 2:56pm

Impedance is only half the story. The Beyers are 600 ohms, which is a lot. They're quite sensitive, though, at 102dB/mW. As a result, they don't need a lot of power, but it's hard for amps to feed them the power they do need. In other words, they need a lot of voltage. Because of their impedance, if they had the same sensitivity as the Sennheiser HD650/HD800 they would need about 1Vrms more to reach 110dB (about 2.5Vrms vs 3.5Vrms). However, because they're much more sensitive (97dB/mW vs 102dB/mw) they actually need about half a volt less.

 

I don't know how powerful your soundcard is. ASUS's site says 2Vrms output, but it doesn't specify under what conditions, distortion levels at that voltage, or even if it's the headphone out (I assume it is). Because high impedance loads are easy on the amp (ironic, huh?) if it can put out 2Vrms it will probably do it at 600 ohms if anything because output impedance won't be an issue. You need 2Vrms to reach 110dB with the T1. I don't think you'd need any more ever, honestly, if that's what the card can put out. If you do decide to get an amp, keep that 2Vrms number in mind (bump it up to 3.5Vrms if you want more headroom, that's for 115dB). Pay attention to distortion and noise as much or more than maximum power, because anything past 4Vrms will be pointless.

 

If you want a cheap amp that will handle the T1 with ease, the Fiio E9 does a great job. It performs with admirably low distortion into high impedance loads, and handles more than enough power before clipping. Just over 7Vrms in fact. Over 80mW into 600 ohms, which is enough to drive the T1 to over 120db!

 

You don't need a DAC if you can get a line-out signal from your soundcard. I'm not sure you can, though.

 

The Essence STX is a good option as stated above. I forgot how powerful the amp is with high impedance loads, because power available to my LCD-2 is crippled by the output impedance.

 

IMPORTANT: The Essence STX has the same "Output/Input Full-Scale Voltage" as your card, so if it can manage 7Vrms into high impedances, that number is obviously not the maximum voltage of the headphone jack. Yours might have the same amp, I don't know. I guess the moral of the story is, if you're getting enough volume don't buy anything else, because ASUS cards measure fine otherwise.


Edited by Head Injury - 9/19/11 at 3:07pm
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post #12 of 16
9/19/11 at 3:56pm
Thread Starter 

i have bought a schiit Lyr that i received today and cannot make it work = = they  give me a RCA to 3.5mm jack and i plug that in my sound card and it doesnt work , i follow the instruction on how to put the tube 

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post #13 of 16
9/19/11 at 4:20pm
Thread Starter 

the tube dont light up :S but their is a orange light that light up just above the tube on the board

 

i say nothing i contact the guys from schiit and they said that is a 230v i try to run in 115v that reall but they have did an error i ordered a 115v = =


Edited by bayerty - 9/19/11 at 5:07pm
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post #14 of 16
9/19/11 at 5:55pm


Can't argue w/ numbers.  Nonetheless, I do prefer and hear big differences w/ my other amps, coloration aside.  Isn't there more to amplification than just THD?

 

Quote:
Originally Posted by mikeaj View Post



No, ST/STX output is 7V rms (about 11 dB higher than 2V rms) on the highest setting, as measured by Stereophile:
http://www.stereophile.com/content/asus-xonar-essence-ststx-soundcards-measurements

Not sure what you mean by "overrated" but the full-scale tests into 600 ohms shows IMD products below -110 dB, with THD pretty much in the noise floor or about as low. I kind of wonder about the ST vs. STX differences. Maybe it has to do with a different computer being used for each test, so maybe with a certain computer, you could get significantly worse performance than the STX tested there. Or maybe (would seem bizarre though) the ST is just significantly worse?

Not to be too presumptuous, but maybe you prefer a less flat presentation with the T1? Or your ST has problems in your computer.

edit: unless you're looking for some special DAC features and indicators, I don't think it would be smart (if you're aiming for a transparent presentation) to ditch the sound card's DAC. These well-tested mass-produced DACs in higher-end sound cards tend to have far fewer inaccuracies than most audiophile gear.
 

That stinks. I'm sure schiit will take care of it though, they are a pleasure to deal w/.

Quote:
Originally Posted by bayerty View Post

the tube dont light up :S but their is a orange light that light up just above the tube on the board

 

i say nothing i contact the guys from schiit and they said that is a 230v i try to run in 115v that reall but they have did an error i ordered a 115v = =



 

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post #15 of 16
9/19/11 at 6:22pm
Sorry for off topic below. To OP, hope you get that sorted out quickly.
Quote:
Originally Posted by rrahman View Post


Can't argue w/ numbers.  Nonetheless, I do prefer and hear big differences w/ my other amps, coloration aside.  Isn't there more to amplification than just THD?

 


Yeah, just something to think about. There's plenty more to an amp than just power and THD (probably IMD is more important anyway), and in some sense people just use those THD/IMD/whatever figures as an overall metric of linearity rather than some kind of magic target number to reach. But, at least to the extent that the STX was tested with the AP analyzer, there didn't really seem to be significant issues with anything, not just THD. It seems to me based on incomplete knowledge that the Essence ST and Burson 160 should sound similar, at least closer to each other than to the Lyr, for instance.

If nothing else, a hybrid tube/solid state amp with supposedly no feedback is a "bold" design, in the least.
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