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Arpiben

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Everything posted by Arpiben

  1. Hi CG, Nothing directed at you either. No answer from my side since I have better experience in microwave vs audio. It is not first time people do evoke PIM possibility for audio signals and link to those RF papers only. Unfortunately I am not aware of any further analysis dealing with it at audio frequencies. Audio signals along a cable/connector do not share the same characteristics as RF (above 1 GHz) electromagnetic modes inside coaxial or waveguides, difficult to compare. In microwave PIM levels are extremely low unless any defective part,corrosion or mountin
  2. Whatever power you are sending your arbitrary tones do you think that you have chance to listen to eventual PIM - 150 dB under ? Amphenol RF connectors aren't use in audio applications or frequency range are they? Just hoping that no audio cable companies will provide any white paper without measurement claiming that they solve PIM issues πŸ˜‰
  3. Typical RF Microwave Channel Spacing C.S. & bandwidth are: 7/14/28/40/56/112 MHz ETSI 10/20/30/40/50 MHz etc ANSI Typical RF Microwave Transmit Power from 0 dBm to +35 dBm Typical RF Microwave Receiver Noise Floor - 100 dBm @ CS = 7 MHz & Frequency below 7GHz PIM is out of concern when you carry only one channel whatever bandwidth since the non linearities order 3/5/7 will never fall down in the Receiver frequency range. In RF microwave transmission for example TX and Rx frequencies are spaced by a few hundred MHz (shifter). In RF microwave Tx &
  4. Well, PIM Passive Intermodulation distortions can be an issue in RF transmission with co located multi channel transmitters and receivers operating in different power ranges and sharing the same transport media: coaxial cable, waveguide, circulator,antenna. Transmission power Tx >=+20 dBm & Receive power sensitivity around Rx = -100 dBm. But unlike RF, Audio non linearities involved are inband. Therefore PIM should be out of concern for audio cables or connectors. Despite your introduction warning, in order to avoid confusion it is probably better not to mention it.πŸ˜‰
  5. Otala/Leinonen/Curl TIM papers are from the seventies. Anything else significant and new to measure at DAC's output? Any new Input stimulation signal rather than sinusoΓ―dal tones?
  6. There is no reason to use long range SFP transceivers (>40 km) for home applications. Dealing with ZR SFPs (80 km/ 1500 nm) one must understand that typically: receiver optical damage is around +5 dBm receiver is saturated for levels above -7 dBm receiver sensitivity (min error less level) is around -22 dBm transmitter max output power is between 0 dBm and +5 dBm Fiber loss (~ 0.5 dB/km) is negligible for home applications. Without attenuators the ZR SFP received level will be too high ( ~ 0 dBm) and out of working range: [. -7 dBm ,- 22 dBm]. Data will b
  7. Correct regarding specifications. BTW there are several methods for measuring lower jitter than own equipment, dual ADC + DSP is one of them. πŸ˜‰
  8. Except that frequency range is from 1MHz up to 400 MHz...πŸ˜‰ (5125a)
  9. Broadcom ICs used in transmission equipment. For such applications, burst absorption is around 100 ms (@port rate) same for typical/default latency constraints at throughput. My point was to have an idea of burst sizes (or duty cycle rate) in typical audio data. To be clear I am sharing same concerns as yours dealing with the utility of such Ethernet regenerators. (latency values @800 Mbps bandwidth) (Ex:10 kB buffer size switch setting measured with ETH tester)
  10. Thanks. The ones I am using have buffer sizes (60MB) adjustable (1/2.5/10 Gbps ports).
  11. The only bottleneck is the EtherReg B side (100Mb) vs A side (1Gb) when data is flooding from B to A.πŸ˜‰ @plissken were you able to read the switch labels if not blanked or erased? In case of proper instrumentation,did you estimate EtherReg's default buffer size?
  12. 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.
  13. 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.πŸ˜‰
  14. 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 diffe
  15. In External clock reference mode, what is happening in case of no 10MHz signal input ( Reference Clock device failure/Off, BNC removed)? Thanks.
  16. @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.
  17. 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...πŸ˜‰
  18. Thanks Miska. I have now a clearer idea about the OOB range you are paying attention to. ,😊
  19. 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.πŸ˜‰ Thanks.
  20. 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 (
  21. Hi Paul, I am ok with the corrections brought by the new release but I still have some pending questions if you allow πŸ˜‰: 1Β° Clock driftt curve seem to have disappeared. 2Β° 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. 3Β° Dealing with subsample offset values can you tell what is the expected resolution? For point 2Β° I understand it all depends on the strategy adopted for the correction but I am a bit disappointed we can not detec
  22. Great Paul! Take your time there are no blocking points πŸ˜‰, therefore no need for a pre release. I will patiently wait. Thanks.
  23. 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.
  24. 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*****.
  25. 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
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