![]() But kudos to Oleg for offering that kind of thing. have ready-made PCBs and parts, but I'm not 100% happy with that design. There are some discussion about this chip in few topics, but I think seperate topic for this could be nice. I think you need some kind of internal state machine to be able to do it like the ADuM4160 and similar parts. USB isn't just differential data, there are some bus states indicated by single-ended signals on some of the pins. But wires should be equal lenght, and maybe twisted if space allows that? Or is it pointless in short distance? Normal opto, GMR, or capacitive isolators are either not fast enough or don't meet all the requirements for USB. And I'm not very familiar with these impedance things. This is far enough apart that there's almost no coupling between the lines-the single-ended impedance is around 1.5O lower than what a single trace's impedance would be.Ĭan anyone give me idea what resistors to use, and what kind of wire between them? Will 24Ω in both ends with any short wire work? I want to use as short wire as I can in there and no connectors between ADuM and TAS1020A. For typical buried microstrips on spacings FR4 stackups the USB traces should be somewhere around 11 or 12mils wide with roughly a 33mil edge to edge spacing (45mils center to center). Be aware that many differential impedance formulas don't take into account the presence of a plane next to the data lines and tend to overestimate the reduction in single-ended impedance due to coupling between the two lines. USB Faq says: What characteristic impedances should I design for in laying out my USB device's traces? A: 30 ohms to ground, 90 ohms differential between the USB data lines. And TAS1020A datasheet has 27.4Ω in the datalines. ![]() USB line terminationĪDuM4160 datasheet says that it needs 24Ω resistors in the output. Please inform me if you find a failure in my "logic".īut to the biggest problem with this. USB1.1 is 12 Mbit/s (Full-Speed) so ADuM4160 should be enough?Īccording to Charles in here Transit can use external clock, so I think I will like to use full duplex and only (max.) 48kHz, but I think it's enough for me. "Note: Due to USB 1.1 bandwidth limitations and hardware constraints,sampling rates above 48000 Hz do not support full duplex (i.e.,simultaneous input and output) mode." Since my card is M-Audio Transit which is quite old, the speed should be enough for it. So I have a few questions, chip I will try is Analog Device ADuM4160. ![]() They could be content with there $500 USB thingies but made the "mistake" to try these sample rate limited professionell toys.I was thinking to build an USB isolator for my soundcard, but I'm not so experienced with these kind of things. The project also makes use of one high quality LDO regulator. Of course a double layer is always better option. The complete datasheet is here: Since the schematic for this project is rather simple, a single layer printed circuit board can be made. There is a good reason why more and more people buy $1200 RedNet devices for mere home audio pleasure. The isolator itsel is build around the ADUM4160 chip from Analog Devices. There where many more requirements I had in my 40plus years in this hobby but I no longer hold myself back by theories. This comparsion was done in an excellent room with highly resolving speakers. DSD, I was perplexed to not be able to reliably tell them apart. I still thought I "required" max sample rate possible but when I compared the same good recording downloaded in 4 different sample rates inkl. So the reqired conversion to DSD was not a requirement anymore to reach a better Sound. That dac was bettered by AKM 4490 with transformer coupling. I even had the AK4137 finally singing to the point that I could not differentiate between it and HQPlayer. In 2018 I thought I require DSD conversion for my pavel Dac. Its good enough someone might say, once you have heard it you will never want to go back.Ĭlick to expand.Out requirements mean nothing. The stereo subs already have their own LP filters. Speakers also already have built-in analog EQ which I don't find a need for (except for a little HF shelving). I already have good ESL speakers that don't need time or phase alignment. I would rather have that than the other stuff. If you can't do it, then I will just take stereo upsampled PCM->DSD256, at the highest quality. If you can do it, how much will it cost including for 3-times as many DSD dacs and 3-times as many very high quality power amps? I require that for each dac channel any PCM digital is to be resampled at the highest quality to either 176kHz or 192kHz, then I want conversion from PCM to DSD256 at the highest quality. Can you do what I want in your DSP box? Suppose I want a fully corrected stereo system with 3-way speakers, and stereo subs.
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