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ALC889 RMAA results at 24/44.1
markanini
post Dec 30 2011, 11:23
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Motherboard is a Gigabyte Z68XP-UD4.


Line out to line in:
http://nerdmoments.byethost7.com/24_44_1.htm
Output set at "50", input at "100", assumed to be nominal levels(?).

Headphone out at max output, unloaded, to line in. (Input reduced to "25"):
http://nerdmoments.byethost7.com/24_44_1_HP.htm

I can do some loaded test of the headphone pre-amp if anyone's interested. I have Ety HF5, Beyer DT250-80, Senn PX-100, Koss KTXPro1, Senn HD201 and Creative EP-630 at hand. I assume I need a 3,5 mm Y splitter with one male and one female connector at the split ends?

Note that while output is 24-bit capable input is 16-bit(oddly, both are 24-bit according to datasheet).

This post has been edited by markanini: Dec 30 2011, 12:04
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xnor
post Jan 1 2012, 19:34
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Hmm, from 1.5 kHz to 70 Hz there's a difference of about 4 dB with the PX100 (impedance ranges from about 34 to 60 ohm) so the output impedance seems to be a lot higher. Could be as high as 100 to 200 ohms?

I think you could play some 50-60 Hz sine wave (e.g. use Audacity to generate them) and measure ac voltage without and with load (e.g. 30 ohm resistor). Then calculate Zout = (Rload * (Vnoload - Vload)) / Vload. Not the most accurate way however. smile.gif

This post has been edited by xnor: Jan 2 2012, 13:33
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Posts in this topic
- markanini   ALC889 RMAA results at 24/44.1   Dec 30 2011, 11:23
- - xnor   QUOTE (markanini @ Dec 30 2011, 12:23) I ...   Dec 30 2011, 12:02
|- - markanini   QUOTE (xnor @ Dec 30 2011, 12:02) QUOTE (...   Dec 30 2011, 12:15
- - xnor   Alright. The audio chip is a Realtek ALC889 right?...   Dec 30 2011, 15:31
- - markanini   Yes.   Dec 30 2011, 17:10
- - markanini   Results for PX100: http://nerdmoments.byethost7.co...   Dec 31 2011, 07:44
|- - saratoga   Those look really bad. I'm assuming thats the...   Dec 31 2011, 07:53
- - markanini   Some sort of best case result with Etymotic HF5: h...   Dec 31 2011, 09:32
- - ErnestS   Make sure you change in realtek software "spe...   Dec 31 2011, 11:01
- - markanini   For the sake of comparison split loopback driving ...   Dec 31 2011, 12:33
- - markanini   Again for comparison, Sansa Fuze. Totally beats pr...   Jan 1 2012, 06:03
- - xnor   Indeed, the problems seem to be output impedance (...   Jan 1 2012, 12:01
- - markanini   Yeah, high output impedance. For fun here's t...   Jan 1 2012, 16:02
|- - ErnestS   I forgot about this topic. QUOTE (markanini ...   Mar 15 2013, 09:52
|- - stv014   QUOTE (ErnestS @ Mar 15 2013, 09:52) Acco...   Mar 25 2013, 18:22
- - markanini   I googled and couldnt find a straight answer to th...   Jan 1 2012, 16:47
|- - saratoga   QUOTE (markanini @ Jan 1 2012, 10:47) I g...   Jan 2 2012, 18:03
- - xnor   Hmm, from 1.5 kHz to 70 Hz there's a differenc...   Jan 1 2012, 19:34
- - skamp   The output impedance isn't just tied to the DA...   Mar 15 2013, 10:06
- - xnor   Z77 Extreme 4 motherboard - I measured about 80 oh...   Mar 25 2013, 19:45
- - Arnold B. Krueger   QUOTE (markanini @ Dec 30 2011, 06:23) Mo...   Mar 25 2013, 20:02
|- - markanini   Try setting the main output to headphone mode. I r...   Mar 25 2013, 22:19
|- - Arnold B. Krueger   Tried setting output to headphones instead of spea...   Mar 27 2013, 14:52
- - db1989   How not to post   Mar 27 2013, 14:58
- - stv014   ALC887 line output (rear jack) on an ASUS motherbo...   Mar 27 2013, 16:52


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