[stv014]

Quote:

Originally Posted by Roller /img/forum/go_quote.gif
 
tgcujo, if you have the soundcard volume set to some form of attenuation, you are effectively lowering the output quality due to a reduction of dynamic range that occurs with digital volume being lowered. If you have fully unattenuated volume from the source, you can then adjust volume through an amp or some other volume controller, as that volume that reaches the amp will carry the full audio signal quality.

That is not the main reason why using an external amplifier may sound better. First, the digital volume control on the card has 24 bit resolution, so there is no real loss of information from the 16 bit source unless the volume is set really low. Second, if the noise floor of the card is inaudible with the headphones (this is possible with the Xonar DX/HD 280 Pro combination, if there are no significant interference issues, and not using the front panel), then the digital volume control is not a problem. The FiiO E9 is a noisy amplifier, so it may even be worse in this aspect.
But with a noisy card (or especially onboard audio, which combines digital volume control with poor SNR), using an amplifier for controlling the volume does make sense.
 
An external amplifier might be worth using because the analog output stage of the sound card may not be great for directly driving headphones, even if it has good quality as a line output. In the case of the Xonar D1/DX (and probably also D2/D2X), the problem is mainly a very high 100 Ohm output impedance. This does affect the bass response of the HD280 Pro audibly; although since these headphones have a "hole" in the mid-bass response, high output impedance does not necessarily make them sound worse, but definitely different.
 

 

[stv014]

Quote:

 
Also, how much better is the DAC on the Xonar Essence STX, comapred to that of the Xonar DX? Looks like Xonar DX + E9 and Xonar Essence STX will come out at about the same price, so I'm comparing those two options.

Technically, the STX is better than the DX+E9 combination (which could still be "good enough"), unless you need the 7.1 output capability of the DX. Other than that, the practical advantage of the latter is that the components can be used and upgraded separately.
 

 

[stv014]

Quote:

Originally Posted by tgcujo /img/forum/go_quote.gif
 
1)What volume level from the Xonar should I feed into the E9 and why(or better yet where can I read more)?

 
According to my tests, the Xonar does not clip at any volume, so it can be set to 100%. But this was not tested under Windows, so I do not know what the Windows drivers do. The maximum output is around 2 Vrms, while the input of the E9 can handle ~2.1 without clipping. If you want to play really safe, set it to slightly less than the maximum.
 

 

[Roller]

Volume control methods have been discussed at length here, and minimizing dynamic range loss still trumps other issues IMHO.
 
And like I said before, different Windows versions handle volume differently, along with processing drivers can do, but that should be disabled by default and setting up the config from there.
 
The Essence STX shouldn't clip, which makes it all the more weird when some people at the Essence STX thread complain about clipping when using the card with volumes that match specs for their OS.
 
stv014, what other SS amps on the E9's price range do you find acceptable?

 

[stv014]

Quote:

Volume control methods have been discussed at length here, and minimizing dynamic range loss still trumps other issues IMHO.

 
Again, it depends on the particular devices being used if there is a benefit in this aspect, or not. For example, the output of the E9 has higher absolute noise level than the Xonar DX (if optimally performing), therefore it will actually have lower dynamic range at a given signal level. Unless the Windows volume control is poorly written or buggy, it should use 24 bit resolution, since the DAC supports that, so playing 16 bit CD audio should still have the full resolution. But a Realtek+E9 or Xonar DX+O2 combination would indeed improve the dynamic range at low volume compared to just the sound card. Although if the absolute SPL of the noise floor is already below the threshold of hearing, further improving it might not make much difference.
By the way, the STX seems to have digital volume and gain control.
 
Quote:

stv014, what other SS amps on the E9's price range do you find acceptable?

 
It is somewhat more expensive if bought fully assembled with batteries (~$150), but the O2 is better for low impedance headphones.
 

 

[Roller]

Quote:

 
Again, it depends on the particular devices being used if there is a benefit in this aspect, or not. For example, the output of the E9 has higher absolute noise level than the Xonar DX (if optimally performing), therefore it will actually have lower dynamic range at a given signal level. Unless the Windows volume control is poorly written or buggy, it should use 24 bit resolution, since the DAC supports that, so playing 16 bit CD audio should still have the full resolution. But a Realtek+E9 or Xonar DX+O2 combination would indeed improve the dynamic range at low volume compared to just the sound card. Although if the absolute SPL of the noise floor is already below the threshold of hearing, further improving it might not make much difference.
By the way, the STX seems to have digital volume and gain control.
 
 
It is somewhat more expensive if bought fully assembled with batteries (~$150), but the O2 is better for low impedance headphones.
 

 
Well, as is the nature of digital volume control, it doesn't provide for 24bits resolution at low volume, but digital volume shouldn't be low, quite the opposite as we both agreed on. Using any sort of analog volume controller, amped or not, would be a better option IMO.
 
If I went for an internal Asus card, I'd go for something like a D2X or a DX, wouldn't touch the STX, both for component integration and overall signature.

I'd trade O2 portability for raw driving power. Are there other brands aside from JDS that are selling the O2? Preferentially with alternative parts selection available.

 

[tgcujo]

Quote:

The FiiO E9 is a noisy amplifier

Not to win noob of the year to consecutive years in a row, but by noisy, are we talking audible background noise whenever there is silence in the music or nothing on at all? Because with my onboard I notice nothing like that at all.
 
I'm very close to slamming the Buy button on this combo
http://www.amazon.com/FiiO-Desktop-Headphone-Amplifier-Dock/dp/B004M172FY/ref=sr_1_1?ie=UTF8&qid=1332206262&sr=8-1
and
http://www.amazon.com/Creative-Blaster-Titanium-Internal-SB1270/dp/B0041OUA38

 

[Roller]

Quote:

Not to win noob of the year to consecutive years in a row, but by noisy, are we talking audible background noise whenever there is silence in the music or nothing on at all? Because with my onboard I notice nothing like that at all.
 
I'm very close to slamming the Buy button on this combo
http://www.amazon.com/FiiO-Desktop-Headphone-Amplifier-Dock/dp/B004M172FY/ref=sr_1_1?ie=UTF8&qid=1332206262&sr=8-1
and
http://www.amazon.com/Creative-Blaster-Titanium-Internal-SB1270/dp/B0041OUA38

You shouldn't get audible hiss unless you use incredibly sensitive headphones.
 
Also, that is a great combo, definitely recommended.

 

[stv014]

Quote:

 
Well, as is the nature of digital volume control, it doesn't provide for 24bits resolution at low volume

Of course it does not, but if the source is 16 bit (like it usually is), then what matters is not losing information from that. The hardware cannot cleanly reproduce the full dynamic range of 24 bit samples anyway, since that would require more than 144 dB of SNR. The following graphs show the loopback recording of a -100 dBFS test signal (16 bit, dithered) with the volume set to -20 dB in the mixer, so the output level is only -120 dB (~2 uV). Only the lowest bits of the 16 bit samples are used, but apparently no information is lost. The bottom graph is averaged to show any distortion products better (there does not seem to be many, the various peaks, including those at about 3, 6, and 9 kHz, are mainly from interference). Note that much of the noise is added by the ADC and 16 bit dithering.
 

 
Ultimately the noise floor is to be kept the lowest at a given volume at the headphones. It may or may not be lower with an amplifier and the digital volume set to 100% than with the sound card only and using the digital volume control. The noisier the sound card is relative to the amplifier, the more likely it is that the amplifier can improve the overall SNR at low volume. But if the amplifier is already used (because the sound card cannot drive the headphones well), then of course 100% digital volume is preferred, unless it causes clipping somewhere.
 

 

[Roller]

Is there any particular reason why it sounds like you're ok with having less than unattenuated volume? I understand perfectly where you're going with your explanation, but if the OP uses high resolution content, then the closest he can be to the (unattainable) 24bits, the better. I'm merely thinking of a best case scenario for content quality.
 
BTW, are you up to date on the full desktop version of the O2?

 

[stv014]

Quote:

Is there any particular reason why it sounds like you're ok with having less than unattenuated volume? I understand perfectly where you're going with your explanation, but if the OP uses high resolution content, then the closest he can be to the (unattainable) 24bits, the better.

I responded specifically to the suggestion that using the E9 would improve dynamic range compared to driving the headphones directly from the sound card (which, however, might not be desirable for other reasons). Dynamic range is the difference (in dB) of the highest signal level without clipping and the noise floor. If the E9 outputs more noise (in A-weighted microvolts) into the headphone load than the Xonar DX, even with the volume turned down to zero, then it does not improve the dynamic range. On the other hand, the much quieter O2 does, even if it might not actually make an audible difference (in theory, the Xonar's noise floor into the HD280 Pro is below the threshold of hearing).
 
To make it clear again, I did not suggest using less than 100% volume if the use of an amplifier is already decided, unless it is necessary to avoid clipping.
 

 

[tgcujo]

Just wanted to post an update for anyone who stumbles upon this.
 
Got my Amplifier and Card in and I have to say I'm loving it, I have nothing to compare it to, but the difference is quite clear.
Sadly, for whatever reason Amazon sent me a unit with the dock connector broken off and the pins bent. Even though I don't plan to use the E7 with it, I'm not a fan of the "ripped-off dock thingy" look, and will be returning it and trying the order again.
 
Thanks your your help peoples 

 

[tgcujo]

Quick question: Is it possible to ruin my HD280's with the E9 if the volume is left high? In normal usage I don't even go further then about 1/3, but I just want to know if the power to break my headphone rest within this amplifier. Thanks