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DarqueKnight

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  1. Thank you for the link to your excellently detailed review of the Emperor Double Crown and subsequent posts. Addressing your questions and comments: 1. Prior evaluations have shown that a clock's square wave shape can depend a lot on the cable. Furthermore, I have not found reliably consistent evidence that a squarer wave shape always correlates with better sound quality. However, @JohnSwenson noted that irregularities in the square wave shape can be an indication of impedance mismatches, which do affect sound quality: https://audiophilestyle.com/forums/topi
  2. Part 1. Introduction The stereophonic performance of an AfterDark Giesemann Trifecta Emperor Double Crown 10 MHz clock (AD EDC) ($2681 USD ) was evaluated in my main home stereo system. The AD EDC was purchased as a performance enhancement accessory for an Uptone Audio EtherREGEN (ER) audiophile Ethernet switch. The AD EDC's performance was compared to that of a BG7TBL 10 MHz clock ($85 USD), an AfterDark Gieseman Queen 10 MHz clock ($751 USD), and the internal clock of the ER switch, a Crystek CCHD-575 25 MHz clock. The ER retails for $650 USD. Phase noise specifications for each
  3. Part 1. Introduction A 2 meter length loaner sample of the new AfterDark (AD) 75 ohm Giesemann EVA BNC-BNC clock cable was evaluated in my two channel stereo system between the AfterDark Emperor Double Crown 10 MHz clock and Uptone Audio EtherREGEN Ethernet switch and between the dCS Puccini U-Clock word clock and dCS Debussy DAC. The AfterDark clock cable was compared to my previous reference clock cable, a Revelation Audio Labs (RAL) Prophecy Cryo-Silver BNC-BNC 75 ohm digital cable (2015 version). The AD loaner clock cable, and a second AD clock cable, were purchased during the
  4. The Rossini is a word clock, which clocks each digital sample of the devices connected to it. The AfterDark clock is an external 10 MHz reference clock, which replaces the less accurate internal clocks of the devices attached to it. The word clocks made by dCS and the 10 MHz reference clocks made by AfterDark serve different functions and are not interchangeable. To use a word clock, a device must have a "word clock" input, or be able to synch to the word clock via some other connection type. To use a 10 MHz reference clock, a device must have a 10 MHz reference clock input. Having
  5. A detailed explanation can be found here: https://www.silabs.com/community/blog.entry.html/2018/01/29/timing_101_6_thec-rCpu https://www.silabs.com/community/blog.entry.html/2018/02/26/timing_101_the_case-7BtO
  6. The plot is a logarithmic scale on the horizontal axis, where every division is a power of 10. At the far left, we have 10^0 = 1 Hz The next division is 10^1 =10 Hz There are spuriae (spikes) at 10 Hz which obsure the measurement because the descending curved line is "interrupted". You have to visualize, or draw, a continuous curved line that has been interrupted by the spuriae. You can then see that the continuous curve intersects the 10 Hz division at about -143 dBc/Hz
  7. Measurement certificate for my AfterDark Giesemann Emperor Double Crown clock. DK - AD - EDC Calibration Certificate.pdf
  8. You can go to an automobile dealer and order two automobiles of the same model, with the same body style, same interior, SAME ENGINE, yet with different transmissions, different suspensions, different brakes, different wheels, different tires, and different engine tuning. It would be incorrect to say they are the same automobile, even though they share most of the same parts. The acceleration, braking, cornering, fuel economy, ride comfort, road feel, interior noise level, overall automotive performance, and PRICE will be significantly different. To the casual observer, the automobiles will ap
  9. I did not/do not rely on short term aural memory. My evaluation methodology is based on making maps of the relative positions (lateral, front to back, and vertical) and relative sizes of all the sound images in the sound stage and then making notes of the quality and characteristics of those sound images. I do not listen for "differences". Blind tests are more suited for people who are not experienced and proficient in stereophonic perception (sound localization, tactile perception, and being able to describe the character and quality of sound). Such listeners will only be able to
  10. Yes, that is a typo in figures 6 and 13. Too late to edit and correct. Thanks for pointing that out. I was expecting the Oyaide to come in second. I was planning to use it in my office system with my yet to be received AfterDark Giesemann Queen Square Wave clock.
  11. AfterDark Giesemann Emperor Double Crown Clock Square Wave With Seven Different 75 Ohm Cables Listening evaluations and oscilloscope square wave plots of seven 75-ohm digital cables were done. Figure 1. Top to bottom, arranged in order of decreasing sound quality: 1. Revelation Audio Labs Prophecy Cryo-Silver BNC-BNC (2015 version, 1m, $449), 2. Revelation Audio Labs Prophecy Cryo-Silver BNC-BNC (2009 version, 1.5m, $349), 3. Oyaide DB-510 BNC-BNC (1.3m, $200), 4. Belden 1865A BNC-BNC (1m, $10), 5. Prosig PSG00542 BNC-BNC (2m, $5), 6. Revelation Audio Labs Prophec
  12. I agree, but @AfterDark. asked me not to post pictures of the inside out of concern for his designs being copied.
  13. Yes. I expected the square waveforms to look sharper as I went up in cable quality. I am actually somewhat of an audio cheapskate. My bias is toward spending the least amount of money to get the sound that I want. I agree with your comment regarding noise effects on cable performance.
  14. Sine waves aren't perfect square waves, and they make very good clock signals. A clock pulse can be any shape (square, sinusoidal, sawtooth, etc.) as long as it is periodic. I am not sure if you are making a general comment or if you are referring to a specific cable. I agree. That is true of a lot of merchandise categories.
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