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Arpiben

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  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 mounting. Rgds.
  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 & Rx frequencies (bands) are spaced by an integer n*CS In RF microwave Tx & Rx signals share the same path. Non linearities are usually generated by defective circulators ( feromagnetics). In case of no non linearities there is a margin of around 150 dB. Forgetting RF microwave transmission, as far as I know, in consumer usage nobody is transmitting multi audio channels CS=44/48/88/96/ etc kHz and simultaneously receiving them at the same point with hundreds dB less! Let's compare apples with apples before providing analogies.
  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 be transmitted with a high error rate and depending on SFP characteristics the receiver may be damaged. Nota: I am not arguing if one prefers the sound with a distorted fiber transmission channel.πŸ˜‰
  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 different signatures among data nothing else.
  15. In External clock reference mode, what is happening in case of no 10MHz signal input ( Reference Clock device failure/Off, BNC removed)? Thanks.
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