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Arpiben

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Everything posted by Arpiben

  1. Be sure that your computer optical output is set in accordance with UD-501 DAC 's specifications: max 24bit/96kHz . Your optical cable may be defective swap it with another one. With headphones on head do not touch a headset metallic part with one hand. Depending on ground of electrical devices in the chain and relative humidity level you may be able to listen to hum. Unless metallic armored (outside fibers: submarine/power lines/underground/etc...) there is no conductive shielding at all in optical cables. "Gold" plated terminations are for aesthetic purposes only.
  2. No need to worry about receive power when dealing with SX & LX SFPs even with short fiber cables. Do not use inappropriate optical transceivers for distances of 40km and above for home audio applications: it makes no sense.😉
  3. Hi @manisandher, In principle, ABX testing and analogue recording (ADC) should be performed simultaneously. Measurement plane can be located at loudspeakers input, DAC's output (via passive splitter) or both of them. Obviously the recording items (ADC / cables/ etc) will interact. My point is to compare data under same conditions. The fact that there is an audibility challenge doesn't help. Question is are you eager to ABX under 'recording' test bench? If not, IMO we are just wasting time and not progressing. My priority is to eventually find different signatures among data nothing else.
  4. In External clock reference mode, what is happening in case of no 10MHz signal input ( Reference Clock device failure/Off, BNC removed)? Thanks.
  5. @austinpop Please note that I am not arguing about Mutec good performances. But for several reasons, like the ones mentioned by @mansr, we should rather compare phase noise at DAC's output where it may matter. The advice is coming from somebody used to deal with phase noise and synchronization in Telecom industry. Feel free to delete.
  6. You are right and Mutec do provide measurements at output ports, quite rare to be mentioned. But one should keep in mind that the slaved oscillator inside DAC has its own noise characteristics...😉
  7. Thanks Miska. I have now a clearer idea about the OOB range you are paying attention to. ,😊
  8. According to you what would be the minimum requirements for the ADC; bandwidth/sampling/ bit resolution/etc? From the curves provided it appears you may be using some industrial ADC like PicoScope ones. Just curious, nothing more.😉 Thanks.
  9. I am not seeing anymore any curve for Clock Drift but it is maybe me..... Rgds Final peak values Reference: 0dB Comparison: 0,144dB Final RMS values Reference: -3,01dB Comparison: -3,011dB Gain= 0dB (1x) DC=0 Phase offset=-0,014423ms (-0,923 samples) Difference (rms) = -48,65dB [-49,4dBA] Correlated Null Depth=89,23dB [86,31dBA] Clock drift: 0,35 ppm Files are NOT a bit-perfect match (match=1,65%) at 16 bits Files are NOT a bit-perfect match (match=0%) at 32 bits Files match @ 49,9958% when reduced to 7,59 bits ---- Phase difference (full bandwidth): 301,35525199606° 0-10kHz: 18,11° 0-20kHz: 250,05° 0-24kHz: 273,80° ---- Variable Group Delay. Frequency matched from 0Hz to 20,0kHz: 1kHz = 4,8μs (1,71°) 2kHz = 1,1μs (0,77°) 4kHz = 201,9ns (0,29°) 8kHz = 536,4ns (1,54°) 16kHz = 626,8ns (3,61°) Timing error (rms jitter): 8,7sec RMS of the difference of spectra: -307,944098772555dB gn=1,00000055023175, dc=0, dr=3,45958E-07, of=-0,923065564 ---Measurements (for a simple sine-wave only)--- Comparison DR = 142,53dB Comparison THD+N = -7,42dB Comparison THD = -161,95dB H1 (1000Hz) = 0dB H2 (2000Hz) = -160,71dB H3 (3000Hz) = -165,61dB H4 (4000Hz) = -168,54dB H5 (5000Hz) = -170,79dB H6 (6000Hz) = -172,41dB H7 (7000Hz) = -173,66dB H8 (8000Hz) = -174,89dB H9 (9000Hz) = -175,96dB H10 (10000Hz) = -176,72dB DONE! Signature: 5d2847516850f38b5b7f631ab6b32783
  10. Hi Paul, I am ok with the corrections brought by the new release but I still have some pending questions if you allow 😉: 1° Clock driftt curve seem to have disappeared. 2° Dealing with integer offset sample values lead to correct/accurate result only if phase drift is unselected. Otherwise we are getting wrong offset/drift values. 3° Dealing with subsample offset values can you tell what is the expected resolution? For point 2° I understand it all depends on the strategy adopted for the correction but I am a bit disappointed we can not detect such cases even with audio files versus simple waves. For point 3°, in case of subsample offsets I would like to know what is the expected resolution. In principle it should depend if you are using or not interpolation and so on... Thanks a lot Paul. Tests have been performed with a 1kHz pure sine with a fixed timed offset: y = sin(2*pi*f0*(t+/-TIE) f0=1kHz / fs=64kHz / TIE= k/fs or 1/(k*fs)
  11. Great Paul! Take your time there are no blocking points 😉, therefore no need for a pre release. I will patiently wait. Thanks.
  12. Hi Paul, Summarizing it DW v1.0.46b introduces a gain factor of 4 for comparison file during Matching as soon as Correct Phase Drift is selected. This behaviour was not encountered in previous releases. Rgds.
  13. Hi @pkane2001 In case it helps the gain=4 applied to Comparison is also present with whatever audio files/FFT length/window provided that: Correct Phase Drift + Measure Simple Waveform + NO Match Gain are enabled. Rgds N.B. if Match Gain is enabled then Comparison will have a correction of something like gn = 0.25*****.
  14. Hi Paul, It is happening with whatever window at least with joined files: no resampling and 64kHz rate as previously mentioned. It is happening only with simple waveform mode and phase drift correction as soon as you press match. Rgds. A.wav B.wav
  15. Completing your reference some measurements. Not all batteries are equal vs noise... http://www.hoffmann-hochfrequenz.de/downloads/NoiseMeasurementsOnChemicalBatteries.pdf
  16. Hi @pkane2001 The phase drift correction is having some issues with simple waveforms at least. 1° There is a gain value of 4 applied to comparison once drift is selected. In order to get the proper estimation one must select Match Gain. I am suspecting there is an upsampling gain not corrected/taken into account. 2° Dealing with integer offset sample values lead to correct/accurate result only if phase drift is unselected. Otherwise we are getting wrong offset/drift values. 3° Dealing with subsample offset values can you tell what is the expected resolution? Tests have been performed with a 1kHz pure sine with a fixed timed offset: y = sin(2*pi*f0*(t+/-TIE) f0=1kHz / fs=64kHz / TIE= k/fs or 1/(k*fs) Rgds
  17. Hi TomCapraro, Is your file a chirp ? Samplers improved a lot in DW but if one wants some more extra dB you may build and apply your own ones. 😉 Rgds.
  18. Yes you did and I am very grateful for it. The point is that for fun and learning purposes I wanted to retrieve the exact frequencies and phases. Now one can generate its own multitone ... Rgds.
  19. Here are the frequencies used by AP's 32 tones test (192 kHz sampling/FFT 65536). IMHO, the distribution is not so obvious .😉 Rgds.
  20. Hi Paul, But at least you got the frequencies right , not yet my case. AP's frequencies aren't equally spaced.😉
  21. Yes from my point of view, but I am not THD expert. It seems that algorithm calculates the difference between Ref&Comp harmonic at first glance. But there is probably some power density calculation within a specified bandwidth which might be tricked...No idea. Paul will help us 😉
  22. Now we are phase aligned 😊. I am getting your results. Comparison THD = -26,07dB H1 (1000Hz) = -1,78dB H3 (3000Hz) = -102,16dB H5 (5000Hz) = -70,5dB H7 (7000Hz) = -94,43dB
  23. Hi Paul, I have been generating ( for fun and learning purposes) multi tones with low crest factor ( Golay_Rudin_Shapiro, Newman, Schroeder, Kitayoshi, etc...). The point is I didn't succeed yet retrieving the algorithm for matching the frequencies of AP file. In principle, it should not be so difficult but I am struggling... Do you mind sharing how did you generate them? Here are some phases : Newman: Schroeder: Kitayoshi:
  24. @TomCapraro Please, can you share your spectrum settings since I am also having correct harmonic levels with Kaiser & Dirichlet? Rgds
  25. Thanks Paul. What is interesting is that file A is also matching the FFT and the THD results are correct! ( compare A with A or swap ref & comp). Rgds.
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