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Posted By: jmone DAC for Headphones and Audiobytes - 07/19/12 02:14 AM
As per my Headphone recommendation thread, I now have a set of Grado SR60 that I plan to use with the PC that also has the Audiobytes hooked up. Couple of things however:

Issue: I've got a call into Axiom on this one, but when I plug the Headphones into the socket on the Audiobytes flying remote it cuts the output to only the drivers on the speakers (but not the tweeter) when the Vol is between say 0-90%, at 90-100% the sound is cut to the speakers. I'm sure this is not right.

Apparent Vol: The apparent Vol on the Grado's is not as "loud" as I may want even when the Audiobyte Flying Remote is at 100%. I tested also with a phone in case it was related to the issue above and it was about the same so I'm guessing that it is just the low power from the PC. My conclusion is there is no amplification of the headphone out on the Audiobyte flying remote and hence if I want more power I'll need something else to boost the signal

External DAC: If this is the case I'm guessing a need something like this - http://www.addictedtoaudio.com.au/Audiogd-NFB121-DAC-and-Headphone-amplifier that supports both a line level out that I can feed to the Audiobyte Amp + a variable headphone output that I can plug the Grados into. I was also recommended this if wanting to increase the apparent vol from portable devices http://www.addictedtoaudio.com.au/Fiio-E05-McKinley-Headphone-Amplifier.

Does this make sense or have I missed something?

Thanks
Nathan
Posted By: JohnK Re: DAC for Headphones and Audiobytes - 07/19/12 02:30 AM
Nathan, the SR60i delivers plenty of volume with any properly operating source. No separate DAC/amplifier should be needed. Continue trying to get the Audiobyte issue resolved with Axiom.
Posted By: jmone Re: DAC for Headphones and Audiobytes - 07/19/12 02:54 AM
I hope you are right but I get the same level of "loudness" if I plug the Grado's directly into the PC. I tried a laptop and the vol from this was significantly louder so I'm still guessing it is more likely related to the output on the PC's Mobo Headphone socket.

EDIT: Also tried the reciever and it obviously has no issues driving the Grado's louder than is comfortable and using this as a comparison I'd guess the PC/Audiobytes at 100% sounds the same as -25DB on the receiver (which I had calibrated with a SPL metre some time ago).

That said it is a shame there is no amplification on the Audiobytes Headphone socket....as the flying remote is pre the amp.
Posted By: jmone Re: DAC for Headphones and Audiobytes - 07/19/12 05:08 AM
FYI - Purchased on of these anyway and will see how it goes - http://www.fiio.com.cn/product/index.aspx?ID=37&MenuID=020301
Posted By: JohnK Re: DAC for Headphones and Audiobytes - 07/19/12 07:28 AM
Unquestionably, that'll work well. But the headphone output on that PC must be defective if it can't even drive an SR60i to a loud level. No added amplification by the Audiobyte should be needed.
Posted By: jmone Re: DAC for Headphones and Audiobytes - 07/19/12 08:13 AM
I should say that at 100% it can drive it to a comfortable level but I agree that it seems odd. The DAC should give me a better quality output as well. It may also be able to replace the Axiom Flying remote.... We shall see I guess one it arrives.
Posted By: BlueJays1 Re: DAC for Headphones and Audiobytes - 07/19/12 11:34 AM
There has to be a setting that is set low somewhere. Those headphones plugged straight into the computer should drive those headphones to ear bleeding volumes. Using this method I find the main computer sound settings and the media player volume settings "work with each other".
Posted By: BlueJays1 Re: DAC for Headphones and Audiobytes - 07/19/12 12:19 PM
Just to clarify, take the flying remote totally out of the chain. It's just screwing up the output and perhaps even compromising sound quality.

Plug the headphone directly to the computer, so the chain is just the computer and the headphone. Then make adjustments on the volume through the main computer volume setting and the media player.
Posted By: jmone Re: DAC for Headphones and Audiobytes - 07/19/12 08:52 PM
Thanks - I've given these suggestions a go already and found similar vol levels....so it could just be the audio out on the ASUS P6T MB is just low. With some luck the DAC will be hear today and I will have some time to test all of this correctly over the next couple of days.

FYI - Brent is going to check out the behavior of the Flying Remote and will get back.
Posted By: jmone Re: DAC for Headphones and Audiobytes - 07/20/12 02:25 AM
Got the DAC / Headphone Amp. For a nooB on this stuff, but I'm pretty impressed with the FiiO E10 2ch DAC (uses a Wolfson 8740) and what it can do for under $80. It just plugged in and worked (no SW just a Windows Driver that auto installed). Key features:
- 2ch, 24bit, 96KHZ
- Headphone Amp / Vol on the front (with a Bass Boost switch if you like that sort of thing)
- High / Low gain switch on the bottom
- Line Out, Coax Out on the back + USB in

It seems to be a big step up from the inbuilt sound card output both for feeding the 2.1 Ch Amp and also for the Headphones. Now to see how stable it is over time!
Posted By: Shane White Re: DAC for Headphones and Audiobytes - 07/20/12 02:43 AM
Headphone volume aside, the DACs in computer soundcards and laptops can be quite variable in quality, so it's worth considering an external DAC. I know people in this forum like to bang on about DACs being a "mature technology", but that's only relevant if that technology is implemented in the device in question.
Posted By: JohnK Re: DAC for Headphones and Audiobytes - 07/20/12 02:57 AM
Shane, we should "bang on" about the realities of modern audio technology when sellers of extravagantly priced items appeal to the uninformed or gullible audio consumer.
Posted By: jmone Re: DAC for Headphones and Audiobytes - 07/20/12 03:51 AM
FYI As my mobo uses the Realtek ALC1200 manufactured specifically for ASUS there are no published specs, though xbitlabs published the following test results in 16bit 44kHz mode:


Posted By: jmone Re: DAC for Headphones and Audiobytes - 07/20/12 04:03 AM
The testing on of the E10 would indicate that this is way better then the mobo (if I read it right) - http://nwavguy.blogspot.com.au/2012/01/fiio-e10-dac.html:
- Freq. Resp. 10K = +/- 0.1 dB A
- Noise A-Wtd dBu = -98.3 C
- -60 dBFS DNR dB = -97.6 C
- THD+N 0 dBFS 10K = 0.005% A
Posted By: jmone Re: DAC for Headphones and Audiobytes - 07/20/12 07:28 AM
Originally Posted By: jmone
Issue: I've got a call into Axiom on this one, but when I plug the Headphones into the socket on the Audiobytes flying remote it cuts the output to only the drivers on the speakers (but not the tweeter) when the Vol is between say 0-90%, at 90-100% the sound is cut to the speakers. I'm sure this is not right.


Wow - something is really odd with the Flying remote. At 90-100% all of a sudden you get a bunch of Hiss even when then is no music, but here is the oddest bit....it introduces hiss on the headphones as well connected to the DAC + Vol will drop significantly on this output. I'm a bit worried that there is some form of short on my remote passed the 90% level (and I've already fried one of the Audiobyte Drivers which thankfully Axiom is replacing)....
Posted By: BlueJays1 Re: DAC for Headphones and Audiobytes - 07/20/12 06:23 PM
Originally Posted By: jmone
The testing on of the E10 would indicate that this is way better then the mobo (if I read it right) - http://nwavguy.blogspot.com.au/2012/01/fiio-e10-dac.html:
- Freq. Resp. 10K = +/- 0.1 dB A
- Noise A-Wtd dBu = -98.3 C
- -60 dBFS DNR dB = -97.6 C
- THD+N 0 dBFS 10K = 0.005% A




The biggest step up that this DAC will provide over your computer is its excellent and LOW headphone output impedance. This where the most obvious differences in sound quality come from between different DACS, amplifiers and MP3 players. NwAVguy measured it at 0.5ohm which is superb.



Posted By: Shane White Re: DAC for Headphones and Audiobytes - 07/26/12 07:24 AM
Originally Posted By: JohnK
Shane, we should "bang on" about the realities of modern audio technology when sellers of extravagantly priced items appeal to the uninformed or gullible audio consumer.

I'm not disagreeing with you John. It's just that, as you say, not all DACs are built to the same standard.
Posted By: BlueJays1 Re: DAC for Headphones and Audiobytes - 07/26/12 01:11 PM
Originally Posted By: Shane White
Originally Posted By: JohnK
Shane, we should "bang on" about the realities of modern audio technology when sellers of extravagantly priced items appeal to the uninformed or gullible audio consumer.

I'm not disagreeing with you John. It's just that, as you say, not all DACs are built to the same standard.


nWavguy's bench test results certainly fall in line with what you are saying. Performance standards for outboard USB DACS are all over the map in terms of output impedance, frequency response, THD+N, IMD, max output, jitter ect. The variations among these DACS are so great that some will even degrade fidelity.

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