AP2712 or modified Asus Xonar U7?

iWoofer

AP2712 or modified Asus Xonar U7
If you go seriously about audio measurements you need something good enough to see your achievement level such as THD, IMD, S/N or dynamic range, frequency response or damping factor. And what choice you have? Used AudioPrecision equipment, old, huge and expensive. Or buy some tiny USB sound card with decent ADC/DAC? Personally my choice is Asus Xonar U7 MK-II for 550RMB or 1/200 part of used AP2722, however, U7 has not so perfect specs yet but good potential for a tweak. So about that simple tweak I want to tell you guys if you have an interest, of course. I've got -119db(A) S/N and THD .000*(-6..-10db) so the old and crazy expensive AP-junk look quite comparable, only 200 times expensive. Actually, especially bad AP doing FFT due to 32768 words(or even 16k if older AP) buffer vs 131072 limit for Arta or 1048576 for SpectraPlus PC software. It is pretty long story, and I don't want to spend my time if you guys have no interest, so if I'll see on this thread at least 50 requests from you guys to continue the story, I'll prepare some simulations regarding OP and resistors noise evaluation for MicroCap and give you details about how to tweak 500RMB USB sound card to not buy AP-junk.

如果你认真对待音频测量，你需要一些足够好的东西来看你的成绩水平，如THD，IMD，S / N或动态范围，频率响应或阻尼系数。你有什么选择？二手AudioPrecision设备，旧的，巨大的，昂贵的。或者购买一些具有不错的ADC / DAC的小型USB声卡？我个人认为华硕Xonar U7 MK-II适用于550RMB或者使用过的AP2722的1/200部分，不过，U7还没有那么完美的规格但是有很好的调整潜力。关于那个简单的调整，我想告诉你们，如果你有兴趣，当然。我有-119db（A）S / N和THD .000 *（ - 6 ..- 10db）所以旧的和疯狂昂贵的AP-junk看起来相当可比，只有200倍的昂贵。实际上，特别糟糕的AP由于32768个字（或者甚至是16k，如果是较旧的AP）缓冲区而不是Arta的131072限制或SpectraPlus PC软件的1048576。这是一个相当长的故事，如果你们没有兴趣，我不想花时间，所以如果我在这个帖子上看到至少有50个请求你们继续讲故事，我会准备一些模拟关于MicroCap的OP和电阻器噪声评估，并为您提供有关如何调整500RMB USB声卡以不购买AP-junk的详细信息。

xmlhifi

Keysight U8903B

iWoofer

49 left ))

yygbs

aoifhaofnoaoiwertnsokdfnsdkfnsa;rjw0enwjt

litguy

看介绍的确不错，希望早日看到你的知识分享

bbp

声卡的性能也是AP测出来的，不然……不会被认可

iWoofer

AP using unperfect analog way(RMS detector) to measure S/N and THD. Of course, they go this way to get as high as possible performances, and they got it but for the same reason, AP typically have very bad HF noise immunity and requires AUX 0025, brick-wall filters etc. However, ADC based system has an ideal mathematical output which is ready for direct analysis in the Matlab for instance. AP has some DSP onboard, however, S2722 ($20000/pcs) has so-so ADC and ridiculously tiny audio buffer and FFT window limited at 16k samples as I remember. So, even if you have an AP machine, you always need some good ADC+PC to see the good resolution FFT online. I used AP 2722/2712 9 years, it is ok if the cost divide by 10 and if the reliability will be improved 10 times as well(OMG, how many times I restored 24C128 EEPROM content by myself to avoid to pay AP repair service 10000RMB!), and please size like Asus U7 as well )) Just 2 weeks ago I prepared some samples for my customers, measured samples with my ADC and got S/N -101db(A). Sent samples to the customers and they start to complain about very unstable S/N AP measurements. Older AP shows -90db(A), newer one -78db(A). Samples contained 2.4GHz RX/TX, and after additional R/C filtering of the outputs, both customer's AP showed 101db(A). BTW, AUX 0025 doesn't help at all..

yhawp

hifidiy,第一次回复帖子，感觉比较其他的你解释，怎么用普通声卡测试，达到AP的效果

iWoofer

yhawp, I don't understand your message. If you asking for details, 45 left.

白雲

u7很有潜力的，我改装过一只。关键是USB便携，用笔记本就能做一些简单的测量，也改过一块STRIX RAID DLX，做成usb声卡了

音随馨动

模拟关于MicroCap的OP和电阻器噪声评估,是仿真数据？

iWoofer

sorry, can not understand your question, google translate that like this: Simulating the OP and resistor noise estimates for MicroCap, is the simulation data?

音随馨动

I'll prepare some simulations regarding OP and resistors noise evaluation for MicroCap and give you details about how to tweak 500RMB USB sound card to not buy AP-junk.    for MicroCap

iWoofer

Sorry, it is nonsense to me. Ok, let's ask somebody else who reading that thread translate your question for me ))

CreaNSR

I wish to hear it，haha

yhawp

非常吸引人的介绍，希望能够看到后期你的发言

音随馨动

很想知道是什么高招，顶一下。还差33个贴子就会公布了。大家加下油

低价PCB制作

顶一下

592657820

RME的adi2 pro，母带级AD/DA，是否可用来做测试？听音同时能兼顾录音需要，顺便做做音频指标测试

iWoofer

I using SpectraPLUS 5.0, ARTA, RTA. Mostly ARTA but all of them shows me similar THD+N. Anyway you can use your own Matlab code if wish.