It's a real pity that the planned firmware updates for Pro and DAC with many improvements and new features are delayed by Corona, global chip crisis, component allocation and and and.... This all blocks an unbelievable amount of time and resources...

Bummer, so this is why it's just Steadyclock being improved, which is still incredible on it's own of course. Can you give us a sneak peek of what is in the making?

As for the delays, it can't be helped with the weird times we live in right now. Looking forward to the ADI-2 becoming even better than it already is.

hello, i just updated with the latest firmware. my Rme still indicates version 34 with the date 12/2019. is this normal?

merci !

I think the 34 refers to the dsp and 35 to the fpga. So all good.

merci !

With firmware 35/34 everything is great (sound). Also a wonderful room depth - even at low volume - with our very special setup (... Neumann KH310A - more about later in this forum).
Try firmware 35/34!
Thanks to RME!

The direct download links of firmware 35/34 (2021-03-19):
https://rme-audio.de/downloads/fut_madiface_mac.zip (MAC)
https://rme-audio.de/downloads/fut_madiface_win.zip (WIN)

Graphs of the above 1 kHz measurements with the RME HDSP9632 in comparison:
ADI-2 DAC FS AK4493 (firmware 27/nn vs 34/nn vs 35/nn) vs ADI-2 (old)
https://www.audiosciencereview.com/foru … ved.21136/

In version 249 and 35 we finished what we had begun in version 238 and 34. In those versions the jitter attenuation was 4 x times higher than before, but a bit unstable in the low frequency area (which caused these low level nearby sidebands reported above). This is now resolved. The new SteadyClock works flawlessly with no difference to before, but jitter attenuation now has a corner frequency no longer around 200 Hz, but at around 1 Hz. That means more than 50 dB jitter reduction also at 50 Hz and similar real-world jitter frequencies. Absolutely top-notch for any kind of incoming clock signal.

Later on I will show the difference in behaviour with measurements on my APx555B.

The values of THD+N and IMD-N change strongly.
THD+N / IMD+N in the output signal are too high.
ADI-2 DAC only (!) gives unstable readings when the "noise component" is measured.

Very noticeable are strong interference frequencies in the spectrum of the REW - RTA. At high values of TD+N these become visible: Two interference frequencies with ~ -101 dBu at a distance of ~ +- 4 Hz each next to the signal frequency of 60 Hz.

The frequency 1 kHz shows two generated signals with ~ -94 dBu: ~ 995.6 Hz and ~ 1004 Hz. Reducing the SPDIF signal brings no change. Another measurement later also showed ~ -78 dBu! These signals are missing in the spectrum of the old ADI-2!

Downgrading from firmware 34/34 to 27/34 (see above) solved these problems. Great!

How nice also that I was completely wrong with my error analysis (too little knowledge about digital "DSP technology").

It would be great if people would investigate if there are differences in sound:

E.g.: "ADI-2 DAC AK4493 Sound FW34/34 vs FW27/34"

Here now some more data for HDSP 9632 users:

RMAA - 24-bit - 44.1 kHz

ADI-2 DAC AK4493  ---  old ADI-2 --- (ADI-2 DAC AK4493 with FW 34/34 - worst case)

Noise level, dB (A)...................114.8   ---   114.0      ---  (either constant or deviate only minimally) 
Dynamic range, dB (A)............114.7   ---   113.9      ---  (either constant or deviate only minimally)
THD, %.......................................0.0002  ---   0.0008   ---  (either constant or deviate only minimally) 
THD + Noise, dB (A)...............-100.9  ---   -95.8        ---  (-81.2)
IMD + Noise, %........................0.0011  ---   0.0016    ---  (0.013)                   
Stereo crosstalk, dB...............114.0   ---   112.8       ---   (either constant or deviate only minimally) 
IMD at 10 kHz, %....................0.0009  ---   0.0016    ---   (either constant or deviate only minimally)

But, with the ADI-2 DAC I have no possibilities to change anything - even according to the manual (EN - Version 34/34). Or have I overlooked something?

Should I still change to flash the former firmware 27/34 to understand parts of my "problems"?

... the ADI-2 DAC only (!) gives unstable readings when the "noise component" is measured.

However, there is one ambiguity with REW:
(IMD+N) cannot be less than (IMD). With the old ADI-2, these values are smaller. I have not yet found an exact description of "IMD-DIN" "TD+N".

You did not measure the residual noise without signal.

THD+N is NOT the most significant value to measure because of the mix of distortion and noise.
I prefer to measure both individually.

Your ADC inside the computer is prone to catch all kinds of noises and interferences, especially ground related ones.

Even balanced connection has its limits in suppressing those.

These two cables is where a ground loop happens for sure, with 10 m size. Measure one channel at a time and unplug the other one.
Stay with Toslink, just to be sure.

And it’s the common standard frequency.
For comparison with the factory specs it’s the one to measure.

shows two generated signals with ~ -94 dBu: ~ 995.6 Hz and ~ 1004 Hz. Reducing the SPDIF signal brings no change. These signals are missing in the spectrum of the old ADI-2!

These signals are low frequency jitter and have nothing to do with your other measurements. They don't change values for IMD or THD, and are (of course) not audible. You can easily remove them by changing clock source to INT at the ADI. They are caused by a change in firmware 34/34, and are already fixed (release in the next firmware update). If you need SPDIF sync for your measurements then you could flash the former firmware 27/34:

http://www.rme-audio.de/downloads/fut_m … _27_34.zip

If 2 different specimen of a known good product gives such results I would question the measurement configuration first.

Plus- it‘s well possible that ADI-2 DAC is set wrong, or you have a ground loop or whatsoever might go wrong.

It was only a functional test:
These are IMD values and they are significantly worse than THD values. Also measurements were taken with 0 dBFS input and max output: VOLUME max (old ADI-2) / VOLUME 0 dB (ADI-2 DAC).

B/T: no
EQ: no
LD: no

DAC-Filter: Sharp
Ref..........+7dBu

Input........SPDIF Coax
Output.....11,29 dBu (REW)
XLR via 2 x 5 m microphone cable

VOL.........0 dB