Update 7/15/18:
I just stumbled across by far the most detailed document I have ever seen on Black Gates™ and it is by Jelmax (the creators of the technology)!
See the 107 page PDF here: Blackgate_Tech_Note_Compilation.
Cable used between the FUN01’s Coax output and the Siglent SDS 1202X-E : Ghent Audio’s E03 (Choseal 4N-OFC (99.99%) 75Ω Coax) along with a standard BNC-to-Phono adapter (RFB-1139 RF Industries)
All oscilloscope captures are made over I/O = CAT6/LAN using EasyScopeX Ver: V100R001B02D01P20 and my Siglent SDS 1202X-E 200 MHz 2Ch Digital Super Phosphor Oscilloscope.
Nichicon Muse (DSD256 11.2MHz Close Up | FFT Normal)
Rubycon Black Gate™ F (DSD256 11.2MHz Close Up | FFT Normal)
Rubycon Black Gate™ F (DSD256 11.2MHz Extreme Close Up | FFT Normal)
It is known that often when going from high to low or vice versa, transients can carry over where they shouldn’t causing small ripples in the beginning of a new step. This phenomena can cause pre-ringing or post-ringing if the sound is in the audible range.
This mechanism creates a sort of digital signature to the incoming signal that you could almost compare to a sort of HW fingerprint, due to how HW dependent this action is in the digital realm. The FUN01 (SU-1 clone) uses a technique of varying the pulse width depending on the frequency called a variable time window. At least, that is what I believe from my observations and my studying the material. Sub-band coding is another way you can optimize the digital domain to filter out the most noise, but I believe the XMOS chipset uses variable pulse sizes instead of sub-band coding.
Nichicon Muse (DSD256 11.2MHz @ Med Time Scale | FFT Averaged 253 Times)
You can easily see the 11.2MHz signal showing on the FFT (only peak past 5MHz). There seems to be a fair bit of noise, but all at or below the dBVrms of the 11.2MHz signal.This is with Nichicon Muse capacitors still in place.
Rubycon Black Gate™ F (DSD256 11.2MHz @ Med Time Scale | FFT Averaged 267 Times)
You can see that the image above in the FFT part has similarities and differences to the FFT shown with the Nichicon Muse capacitors, this one has been averaged over almost the same number of periods. I noticed the additional signals showing up out near 10Mhz so I took a closer look with the FFT on a 10dB scale instead of 20dB and here is what I saw after I reset the FFT average.
Rubycon Black Gate™ F (DSD256 11.2MHz @ Med Time Scale | FFT Averaged 56 times)
Looks pretty good now, I believe it must have been from bumping the cable or something earlier that caused that harmonic to pop up.
Rubycon Black Gate™ F (DSD256 11.2MHz @ Med Time Scale | FFT Average 213 Times)
When playing with the settings in foobar2000, I found out that using DSDTranscoder to convert DSD or FLAC into any DSD that your DAC can handle, in my case DSD256, created a completely different waveform on the FFT than the native DSD decoding does and I wanted to make sure to show this (below).
Rubycon Black Gate™ F (DSD64 2.8MHz @ Med Time Scale | FFT Averaged 195 Times)
Now here is a look at some FLAC (48kHz – 16-bit) for contrast.
Rubycon Black Gate™ F (48kHz 16-bit FLAC @ Med Time Scale | FFT Averaged 302 Times)
Rubycon Black Gate™ F (48kHz 16-bit FLAC @ Med Time Scale | FFT Averaged 302 Times)
