Pdxwayne
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Let's assume this statement is 100% correct: Transparent DAC and HPA (as measured by Amir) should all sound the same.
Since joining ASR more than 1.5 years ago, I have purchased 5 DAC and 4 HPA (for features and different usages), all measured as transparent and recommended by Amir. My experiences so far give me serious doubts about the statement above. If the statement above is 100% correct, then I can only assume many of the items I purchased contained inferior components as compared to the "golden samples" sent to Amir for measurements.
My experience so far (more links at the bottom of post if you have lots of time to read):
DAC:
Ordered 5, returned 2, and one I kept has observed differences.
*Returned SMSL M500 because the screen is defective. This is either very bad quality control or using lesser quality parts.....
*Returned Topping D30Pro because of various reasons. First of all, I noticed that it sounded not as clean as Gustard X16. SINAD and freq responses as measured by me looked fine. But, It did the worse in loopback captured tests in comparison to E30 and X16. Had strange noise issue when playing back diff of captured file vs original. I could even get 8/8 ABX tests when comparing captured file vs original. This is still an unsolved mystery. Could this caused by using lower quality and/or out of tolerance parts in certain runs?
*My Gustard X16 has channel imbalance of ~0.2db. Did the manufacturer use slightly out of spec components for certain runs?
*My Gustard X16 gives different clues when running online blind timing tests, when using 44.1 vs 48Khz format in Windows laptop. It is not feasible to do a proper blind test at home to satisfied the objectivists. But, I welcome an official blind test challenge at Amir's place anytime. Anyway, I wonder if this could be caused by poorer parts quality...
HPA:
Ordered 4, returned 1, and two I kept have observed differences.
*Returned SMSL HO200 because the low bass sounded not as good as L30 (only when using K371 headphone and not my other headphone). Only did voltage matched sighted tests and not feasible to perform blind tests at home. Could part quality cause such difference?
*I got a replacement L30 due to a recall (caused by static electric shock issue). The replacement L30 is hotter than the original by several Celsius (as measured on the top of the case). It was verified via infrared thermometer. Could inferior parts cause higher temperature?
*When using in a chain, my Gustard H16 provides different clues as L30, when running online blind timing tests. Again, I could only perform sighted voltage matched checks. Not feasible to perform blink tests at home. But, I welcome official ASR blind test challenge at Amir's place anytime. Could part quality cause such differences?
Of the 9 items I bought, 6 of them have observed issues/differences. 6/9!!!
So what do yo think? Other than some of you will still think that most of my observations could be just "imagination" and "bias", what are the other logical explanations?
Could the Chinese manufacturer(s) (I wonder if Gustard, SMSL, Topping, etc. are using the same general contractor) knowingly substitute lower quality and/or out of spec components for certain runs?
Or, maybe they all still measured fine (using Amir's methods), but due to certain not yet known reasons, when used in specific chain for specific test, they are just not sounding the same?
Is it time to do an official gathering at Amir's place to further investigate? : )
-------------------------------------------------------------------------------------------------------------------------------------------------
If you have plenty of free time on hand, here are some links that provide more details.
Topping D30pro sounded different:
Gustard X16 sounded different mainly due to 0.2db off:
Gustard X16 sounded different when using 44.1K vs 48K format to perform online timing tests:
SMSL HO200 bass notes different:
Gustard H16 sounded different than L30 when performing online timing tests:
Since joining ASR more than 1.5 years ago, I have purchased 5 DAC and 4 HPA (for features and different usages), all measured as transparent and recommended by Amir. My experiences so far give me serious doubts about the statement above. If the statement above is 100% correct, then I can only assume many of the items I purchased contained inferior components as compared to the "golden samples" sent to Amir for measurements.
My experience so far (more links at the bottom of post if you have lots of time to read):
DAC:
Ordered 5, returned 2, and one I kept has observed differences.
*Returned SMSL M500 because the screen is defective. This is either very bad quality control or using lesser quality parts.....
*Returned Topping D30Pro because of various reasons. First of all, I noticed that it sounded not as clean as Gustard X16. SINAD and freq responses as measured by me looked fine. But, It did the worse in loopback captured tests in comparison to E30 and X16. Had strange noise issue when playing back diff of captured file vs original. I could even get 8/8 ABX tests when comparing captured file vs original. This is still an unsolved mystery. Could this caused by using lower quality and/or out of tolerance parts in certain runs?
*My Gustard X16 has channel imbalance of ~0.2db. Did the manufacturer use slightly out of spec components for certain runs?
*My Gustard X16 gives different clues when running online blind timing tests, when using 44.1 vs 48Khz format in Windows laptop. It is not feasible to do a proper blind test at home to satisfied the objectivists. But, I welcome an official blind test challenge at Amir's place anytime. Anyway, I wonder if this could be caused by poorer parts quality...
HPA:
Ordered 4, returned 1, and two I kept have observed differences.
*Returned SMSL HO200 because the low bass sounded not as good as L30 (only when using K371 headphone and not my other headphone). Only did voltage matched sighted tests and not feasible to perform blind tests at home. Could part quality cause such difference?
*I got a replacement L30 due to a recall (caused by static electric shock issue). The replacement L30 is hotter than the original by several Celsius (as measured on the top of the case). It was verified via infrared thermometer. Could inferior parts cause higher temperature?
*When using in a chain, my Gustard H16 provides different clues as L30, when running online blind timing tests. Again, I could only perform sighted voltage matched checks. Not feasible to perform blink tests at home. But, I welcome official ASR blind test challenge at Amir's place anytime. Could part quality cause such differences?
Of the 9 items I bought, 6 of them have observed issues/differences. 6/9!!!
So what do yo think? Other than some of you will still think that most of my observations could be just "imagination" and "bias", what are the other logical explanations?
Could the Chinese manufacturer(s) (I wonder if Gustard, SMSL, Topping, etc. are using the same general contractor) knowingly substitute lower quality and/or out of spec components for certain runs?
Or, maybe they all still measured fine (using Amir's methods), but due to certain not yet known reasons, when used in specific chain for specific test, they are just not sounding the same?
Is it time to do an official gathering at Amir's place to further investigate? : )
-------------------------------------------------------------------------------------------------------------------------------------------------
If you have plenty of free time on hand, here are some links that provide more details.
Topping D30pro sounded different:
Both DAC are transparent as measures by Amir, why one not as clean sounding as the other?
All, Before you start typing words like "brain", "imagination", please save your energy. I won't response to such replies. I have done multiple online blind tests, done multiple ABX tests, and a coupe of DAC vs DAC double blind tests. So, please save the lectures about voltage match...
www.audiosciencereview.com
Gustard X16 sounded different mainly due to 0.2db off:
DAC burn-in/break-in? My Gustard X16 measurements
This is a post copied from my other thread at https://www.audiosciencereview.com/forum/index.php?threads/phase-shift-and-echo-trails-length-illusion.20618/post-684254. When I first got my X16 into my stereo setup, my first impression was E30 have better highs. Because I did voltages...
www.audiosciencereview.com
Gustard X16 sounded different when using 44.1K vs 48K format to perform online timing tests:
Timing test results - a poll
The simple 2 ways timing online blind test is here: https://www.audiocheck.net/blindtests_timing_2w.php?time=100 I tried a while back using smartphone and could do 10/10 for 10ms. Lower was tougher for me. The site does not show the statistics of all those who tried. So I am curious how ASR...
www.audiosciencereview.com
SMSL HO200 bass notes different:
I feel bass difference between headphone amps. How to check phase mismatch?
Before measurements, I sensed bass difference between Topping L30 and SMSL HO200. L30 seems "cleaner" than HO200 in bass "feels". After voltage matched, I still feel the same. Voltage matched done: *Matched amp's left channel within 0.001V. *Made sure left and right channel balance of each...
www.audiosciencereview.com
Gustard H16 sounded different than L30 when performing online timing tests:
DAC and amp combos did not give same clues when running online blind tests. Why? What would be the desired clue?
When running online blind timing tests yesterday, I heard different clues when using multiple combination of dac and amps. I wonder why. I thought, as long as I am using transparent DAC and amp, I can mix and match them and any combo will sound the same. But not this case. Is it okay? More...
www.audiosciencereview.com