Aqua Formula xHD D/A 那狗血的测试表现
本帖最后由 snova 于 2018-6-21 15:27 编辑在2018年有如此的DAC，真是刷新听众的三观啊，文末评语：Most of the questionable aspects of the Aqua Formula xHD's measured performance stem from its lack of a reconstruction filter. But its poor rejection of word-clock jitter, and that inadequate transformer used to implement the balanced outputs, are flaws that should have been avoided.—John Atkinson
原文地址
https://www.stereophile.com/cont ... cessor-measurements
When I tested the Formula xHD's harmonic distortion from its balanced outputs, I got a surprise: With the 50Hz tone I usually use, the distortion was extremely high. Even at –3dBFS into 100k ohms (fig.9), the third harmonic lay at just –20dB (10%), which will be very audible.
Fig.9 Aqua Formula xHD, balanced output, spectrum of 50Hz sinewave, DC–1kHz, at –3dBFS into 100k ohms (left channel blue, right red; linear frequency scale).
不懂，解释一下呢 233 本帖最后由 snova 于 2018-6-20 10:48 编辑
这要怎么解释？
平衡口谐波失真这么逆天，味道机?;P 坐等一波“不看参数，耳朵收货“的粉丝来救场。 奇次谐波比偶次高这么多，那听感应该很清晰明亮啊 这机器大概出故障了 再测个la scala看看，不是说这个才是味道机吗？ 故障这种事杂志遇到过，不是这么处理的。Atkinson的评语没有留余地。 本帖最后由 小白 于 2018-6-20 12:37 编辑
Sterophile挺有意思的，因为你看它对Formula xHD解码器的具体评测，结论部分是非常正面的：
Conclusions
Aqua Acoustic Quality's Formula xHD is an extremely fine-sounding DAC whose warmth and ability to decode files of extremely high resolution should win it many admirers. Many will also applaud its designer's rejection of digital filters, oversampling, upsampling, and MQA. Thanks to the Formula xHD's ability to smooth over digital's rough edges, I don't hesitate to recommend that it be auditioned by anyone with $17,000 to spare, and whose system suffers from bright or harsh sound, or who values, above all else. the warmth and bloom often ascribed to analog sources.
评测者用到了extremely fine-sounding“极其好声”、don't hesitate to recommend“毫不犹豫地推荐”、warmth and bloom often ascribed to analog sources“常见于模拟音源的温暖和光彩”这样的词汇。
可以说这篇Stereophile的评测文章自家打仗了，主观结论和客观测试打架。
早看到了……神经病一样的中低频失真……（10%到70%……）
我也怀疑坏了2333 https://www.stereophile.com/content/holoaudio-spring-kitsun%C3%A9-tuned-edition-level-3-da-processor-art-dudley-july-2018#Od10CgQJM6hJbz8S.99
https://www.stereophile.com/content/holoaudio-spring-kitsun%C3%A9-tuned-edition-level-3-da-processor-page-2#hVFgd4stE4tXsOKO.99
这个不知道靠谱么？ One of the earliest but incorrect criticisms of CD players was that they produced a "stepped" waveform. The criticism was incorrect because all players back then incorporated an analog or digital high-order, low-pass reconstruction filter that "smoothed" the waveform. Ironically, because D/A processors like the Aqua don't have a reconstruction filter, their output is indeed stepped, as you can see from fig.15.
Read more at https://www.stereophile.com/content/aqua-acoustic-quality-aqua-formula-xhd-da-processor-measurements#pQpLbBMYTItRJerZ.99
哦还有后续呢，这个图之前没看到……1k正弦波能弄出阶梯波形真的福气
真正意义上的“数码声” 单端输出谐波失真要低一大截，但依然属于不好的范畴。狗血的是测试表现，确实不排除人家声音好，对不？
不知aqua以后会不会有follow-up，如有，杂志也会附在文末。
早前follow-up中，苍白的辩解也不少，有兴趣的烧友可以搜搜那几个比较有争议牌子:lol 比如audio note? :lol
