A few measurements of RME ADI-2 PRO fs and Swissonic Converter DA 24/192

[LTig]

Just got a new toy (RME ADI-2 PRO fs) and played a bit with it using REW on Linux. Here is a photo with the RME and a Swissonic Converter DA 24/192 (and for size comparison a Genelec 8020 active nearfield monitor speaker).

1. Loopback of RME ADI-2 PRO fs: XLR out -> XLR in
   1. THD test using sinus 1 kHz -4 dB at 96 kHz/24 bit
      
      
      Results:
      131072-point spectrum using Hann window and 32 averages
      Input RMS -4,0 dBFS, -4,0 dBC, -4,0 dBA
      Distortion at 1.000,0 Hz, -4,0 dBFS based on 8 harmonics:
      THD: 0,00011 %
      N: 0,00067 %
      THD+N: 0,00067 %
      2nd harmonic 0,000085% 110 deg
      3rd harmonic 0,000044% -51 deg
      4th harmonic 0,000032% 103 deg
      5th harmonic 0,000026% -25 deg
      6th harmonic 0,000021% 97 deg
      7th harmonic 0,000022% -169 deg
      8th harmonic 0,000006% 90 deg
      9th harmonic 0,000003% -74 deg
   2. IMD test using CCIF (19 + 20 kHz) -10 dB at 96 kHz/24 bit
      
      
      Results:
      131072-point spectrum using Hann window and 32 averages
      Input RMS -7,0 dBFS, -18,0 dBC, -16,0 dBA
      IMD is 0,000092 % for f1 = 19.000 Hz, f2 = 20.000 Hz
      d2L: 0,000092%
      
2. RME ADI-2 PRO fs SPDIF Coax out -> Swissonic Converter DA 24/192 RCA-out -> RME XLR in (asymmetric)
   1. THD test using sinus 1 kHz -4 dB at 96 kHz/24 bit
      
      
      Results:
      131072-point spectrum using Hann window and 32 averages
      Input RMS -5,9 dBFS, -5,9 dBC, -5,9 dBA
      Distortion at 1.000,0 Hz, -5,9 dBFS based on 8 harmonics:
      THD: 0,026 %
      N: 0,011 %
      THD+N: 0,028 %
      2nd harmonic 0,012% -84 deg
      3rd harmonic 0,021% -2 deg
      4th harmonic 0,0013% 96 deg
      5th harmonic 0,0011% 150 deg
      6th harmonic 0,00035% -73 deg
      7th harmonic 0,0048% 158 deg
      8th harmonic 0,00023% -61 deg
      9th harmonic 0,0049% 153 deg
      
      
   2. IMD test using CCIF (19 + 20 kHz) -10 dB at 96 kHz/24 bit
      
      
      Result:131072-point spectrum using Hann window and 32 averages
      Input RMS -9,5 dBFS, -20,4 dBC, -18,5 dBA
      IMD is 0,0068 % for f1 = 19.000 Hz, f2 = 20.000 Hz
      d2L: 0,0068%
      

Conclusion:
The Swissonics retails for € 35.- (!), the RME for € 1500.- (both @ Thomann). You pay a lot more for the RME (which is much more than just a DAC, of course), but you get also much better results.

Other comments:

• For Jitter tests I need the J-Test signal to play outside of REW (REW does not support it). I couldn't find a file for download so I may have to create it by myself - not tonight though.
• REW cannot play signals with 192 kHz samplerate without stutter. VLC has no problems, aplay (ALSA command line player) neither.
• My Notebook with Windows 10 was not able to play bit correct data to the RME. I would like to use the Notebook for sensitive measurements since it can run on battery and with the RME fed by a 12V lead battery.
• These are my first measurements posted here. Feel free to comment what I can do better, whether the parameters are consistent with Amir, or if there is better software than REW for this purpose.