"ADI-2 DAC (AK4493) with sound problems - THD+N + IMD+N change strongly"
This problem has been reported in the RME forum. Matthias Carstens from RME (here: @MC_RME) identified the problem as jitter.
Workaround: Downgrade to FW27/34
(ADI-2 DAC FS (AK4493) had firmware 34/34)
https://forum.rme-audio.de/viewtopic.php?pid=165958#p165958
No graphics can be posted in the RME Forum. So, now here are some firmware measurements compared to the old ADI-2 (Hardware 1.4) - for your information and if you want to find out whether the firmware 27/34 sounds better as FW34/34. Details about the measurement system can be found in the link above.
Please note:
ADI-2-DAC-FS with FW27/34 and ADI-2-old-HW1.4 (Hardware 1.4) have stable measured values (THD+N / IMD+N).
ADI-2-DAC-FS with FW34/34 has fluctuating measured values (THD+N / IMD+N) - worst case values are shown!
The jitter is << -60 dB (0.1%) and thus not audible. However, we are only measuring a simple, single tone (1 kHz) and this is not a dynamic measurement! With complex audio signals, differences might be audible.
From left to right:
ADI-2-DAC-FS (FW34/34).......ADI-2-DAC-FS (FW27/34).......ADI-2-old-HW1.4
VOL: 0 dB
+12,87 dBu.....................+12,88 dBu...................+12,88 dBu
VOL: -20 dB
-7,12 dBu...........................-7,12 dBu......................-7,17 dBu
VOL: -40 dB
-27.13 dBu.......................-27,13 dBu....................-27,15 dBu
1-ADI-2-DAC-FS (AK4493)_FW34-34_linear_OUT+12.87 dBu.jpg
2-ADI-2-DAC-FS (AK4493)_FW27-34_linear_OUT+12.88 dBu.jpg
3-ADI-2-old_OUT+12.88 dBu.jpg
4-ADI-2-DAC-FS (AK4493)_FW34-34_linear_OUT-7.12 dBu.jpg
7-ADI-2-DAC-FS (AK4493)_FW34-34_linear_OUT-27.13 dBu.jpg
10-ADI-2-DAC-FS (AK4493)_FW34-34_linear_OUT-7.19 dBu_-20dBFS.jpg
This problem has been reported in the RME forum. Matthias Carstens from RME (here: @MC_RME) identified the problem as jitter.
Workaround: Downgrade to FW27/34
(ADI-2 DAC FS (AK4493) had firmware 34/34)
https://forum.rme-audio.de/viewtopic.php?pid=165958#p165958
No graphics can be posted in the RME Forum. So, now here are some firmware measurements compared to the old ADI-2 (Hardware 1.4) - for your information and if you want to find out whether the firmware 27/34 sounds better as FW34/34. Details about the measurement system can be found in the link above.
Please note:
ADI-2-DAC-FS with FW27/34 and ADI-2-old-HW1.4 (Hardware 1.4) have stable measured values (THD+N / IMD+N).
ADI-2-DAC-FS with FW34/34 has fluctuating measured values (THD+N / IMD+N) - worst case values are shown!
The jitter is << -60 dB (0.1%) and thus not audible. However, we are only measuring a simple, single tone (1 kHz) and this is not a dynamic measurement! With complex audio signals, differences might be audible.
From left to right:
ADI-2-DAC-FS (FW34/34).......ADI-2-DAC-FS (FW27/34).......ADI-2-old-HW1.4
VOL: 0 dB
+12,87 dBu.....................+12,88 dBu...................+12,88 dBu
VOL: -20 dB
-7,12 dBu...........................-7,12 dBu......................-7,17 dBu
VOL: -40 dB
-27.13 dBu.......................-27,13 dBu....................-27,15 dBu
1-ADI-2-DAC-FS (AK4493)_FW34-34_linear_OUT+12.87 dBu.jpg
2-ADI-2-DAC-FS (AK4493)_FW27-34_linear_OUT+12.88 dBu.jpg
3-ADI-2-old_OUT+12.88 dBu.jpg
4-ADI-2-DAC-FS (AK4493)_FW34-34_linear_OUT-7.12 dBu.jpg
7-ADI-2-DAC-FS (AK4493)_FW34-34_linear_OUT-27.13 dBu.jpg
10-ADI-2-DAC-FS (AK4493)_FW34-34_linear_OUT-7.19 dBu_-20dBFS.jpg
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