Recent content by chenxuwen

Thanks. Thanks for letting me know about the Ceramic capacitor voltage coefficient, I did not know it is that severe. I am gonna use 25V 100uF 1206 with X5R. Would that be a better option then? Beside, it is only 0.1uF in there now, even it goes down to 20uF at 5V, it still more than the 10uF...

I just got confused by https://www.audiosciencereview.com/forum/index.php?threads/e-mu-0204-in-2023-rmaa-measurements-and-some-modifications.45428/ in which the noise level test is obviously worse than mine. But it has a better Peak Level, dB FS. Could you explain that? Is RMAA's algorithm...

Dear All, I have done the AK4393->AK4396 Mod. I measured the result with a 2i2 gen 4 and realized many things. 1. The ADCs in my Echo Mona are acually 2 pieces of AK5383 instead of AK5393, so its self mesurement showing 110db dynamic range is at its limit. Moreover, I have found the vref...

Again, thanks for helping me. Here is a photo of the board of the external box. After the LM2940-5V, there are reg1117-3.3 for the 3.3V supplies. The lm2940s are currently replaced by LT1963S. The input circuit is not a INA217/THAT1510, it is 4 INA134s on the right side of the photo under the...

Thanks for helping me. The stock and now have two dip 8 size vco (tcxo now), one 11.2896 and one 24.576 inside for the clock. The powersupply is from one switch powersupply, lc filter, then lm2940+2990 (analog and digital seperate), then another 3.3v regulator. All capacitors have been recapped.

Thanks for your input. I now see the problems now. Putting together the input of @wwenze and @AnalogSteph, the THD+N is limited by the following factors: 1. The input INA134 at the mic stage. Its sensitivity might be the biggest factor as I need compressed air cleaner on the input ports to reach...

Dear All, May I share the RMAA result of my Echo Mona? I prefer this one to my ASUS Xonar D2 which has 115db dynamic range. (Will post its RMAA result if interest is showed, if it is OK and if I am posting at the right place.) It is still working nicely today, but I cannot understand why its...

Then it puzzles me why other's RMAA result is so different from the AP test here. Is there a reason you can think of? AP is the standard while RMAA usually gives a result worse than actual.

Such a result is very unexpected. There are multiple RMAA results available for the card and they are usually 117db or something... Like this one: http://borisgermanov.blogspot.com/2014/04/asus-xonar-essence-stx-rmaa-tests.html Of course, those result are not AP2 results and ASUS insist that...