1 (edited by jiw 2019-07-12 19:50:41)

Topic: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

Disclaimer: I have already contacted the RME support about this almost a month ago but after receiving back a reference to the manual (5.6 on p. 10) which did not resolve the problem, I have not heard back.

Below is a slightly adapted description of the problem I have sent to the RME support (additions marked in italics).

DIGICheck does not show the data being recorded by the DAC. The OS' and QuickTime Player's recording function show that a signal of expected amplitude is present at the SPDIF input/USB output of the DAC. 

DIGICheck shows the DAC as an available input device but regardless of the signal, the BitStatistic shows all zeroes while the DAC's State Overview shows 16 or 24 bits and any DIGICheck meter is all black/dark or reads UFL. Still, DIGICheck sets the spectrum analyser according to the sample rate of the DAC's internal clock (set in Audio MIDI Setup -> Audio Devices).

Whether the DAC's input is set as 'Source: Optical' or 'Source: USB (Rec. opt.)' has no influence on the above behaviour.

Signal flow: MacBook Pro (Retina, 13-inch, Early 2015, macOS 10.14.5) -> SPDIF optical -> ADI-2 DAC (FW 26/28 or FW26/30) -> USB -> MacBook Pro (same unit).

DIGICheck is version 0.73.

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

I did some more testing on this using the Bit Test.

Using iTunes as playback software and QuickTime Player as recording software, the recorded signal from the DAC is bit perfect up to 24/192 regardless of Source being Optical or USB (Rec. opt.).

The signal flow between playback and recording software is as in the original post.

For playback, iTunes was set to full volume (slider all the way to the right) and all enhancements were disabled or set such that the signal is not altered by iTunes. For recording, on the QuickTime Player, the DAC was set as the microphone and the quality was set to maximum. The sample rate and word length (number of bits) for the SPDIF output and the sample rate of the DAC were set in the Audio MIDI Setup's Audio Devices such that the word length and sample rate were those of the bit test file being played back.

Playing back the 32 bit tests using USB, shows that iTunes truncates at 24 bits as the test passes for all sample rates but only at 24 bit. Using the tests at 16 and 24 bits and also using SPDIF, as it is limited to 24 bits, the test passes for both 16 bits and 24 bits for all sample rates for both SPDIF and USB, i.e. the signal from iTunes to the DAC is bit perfect for both USB and SPDIF up to 24/192.

Thus, the signal being sent to the DAC is bit perfect up to 24/192.

The bit perfect transmission from the DAC was tested by recording the incoming bit test (and bit perfect) signal and subsequently playing the recorded signal back in iTunes. This was done both for Source being Optical and Source being USB (Rec. opt.). All the recorded bit test signals resulted in the same pass as the original bit test signals regardless of Source being Optical or USB (Rec. opt.).

Thus, the recorded signal from the DAC is bit perfect up to 24/192 regardless of Source being Optical or USB (Rec. opt.).

3

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

Security & Privacy, Privacy, Microphone: Allow DIGICheck.

Regards
Matthias Carstens
RME

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

Thanks, that made it work. Although I am not sure why the support didn't manage to provide that via mail.

Now, about my second post. The manual says on page 10

To enable the recording of the SPDIF input via USB go to I/O, Source, and select either USB
(Rec opt.) or USB (Rec coax).

My testing suggest that this is not the case. Rather, it seems that the DAC records any SPDIF signal present at the selected playback/recording input and transmits it via USB if connected.

5

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

But clocking might be wrong then.

Regards
Matthias Carstens
RME

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

Even if the USB sample rate is the same as the SPDIF sample rate?

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

I did some more testing on digital recording for Source being Optical rather than USB (Rec. opt.).

If the USB sample rate is the SPDIF sample rate, a single playback of the test files is recorded with zero errors. The same is true for USB (Rec. opt.).

As in my previous testing, I used iTunes for playback and QuickTime Player for recording.

First, the recording was started, then the bit test file was played back and afterwards the recording was ended. Thus, the sequence in the recordings was the same as that in the bit test files.

Using MATLAB to align the recordings and originals at the first non-zero sample and calculate the sum of squared differences for each sample point where the files overlap, gives zero for all sample rates and word length.

Thus, clocking seems to be no cause for concern if the USB sample rate is the same as the SPDIF sample rate.

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

Habe ein ähnliches Problem: Digicheck zeigt nichts an. Digicheck darf Mikrofon benutzen. Macos Mojave.

Gibt es Vorschläge?
Danke

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

Welcher Eingang (Source) ist am DAC gewählt?

Laut DAC Handbuch S. 47:

DIGICheck 0.73 [...] kann derzeit nur die SPDIF-Eingangsdaten anzeigen.

Da Sie scheinbar mehrere RME Geräte haben, welches Audiogerät ist in DIGICheck als Eingang gewählt?

Handbuch: http://www.rme-audio.de/download/adi2dac_d.pdf

10

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

jiw wrote:

I did some more testing on digital recording for Source being Optical rather than USB (Rec. opt.).

If the USB sample rate is the SPDIF sample rate, a single playback of the test files is recorded with zero errors. The same is true for USB (Rec. opt.).

As in my previous testing, I used iTunes for playback and QuickTime Player for recording.

First, the recording was started, then the bit test file was played back and afterwards the recording was ended. Thus, the sequence in the recordings was the same as that in the bit test files.

Using MATLAB to align the recordings and originals at the first non-zero sample and calculate the sum of squared differences for each sample point where the files overlap, gives zero for all sample rates and word length.

Thus, clocking seems to be no cause for concern if the USB sample rate is the same as the SPDIF sample rate.

I made the error to have MATLAB not read the files in their native format but rather in its standard 64 bit double precision float. The recordings are 32 bit integer files while the 24 bit test file is 32 bit integer but the 16 bit test file actually is 16 bit integer. After correcting for the above, the comparison can thus only be made with the 24 bit test.

However, this returns the same result as before: No errors using both Optical and USB (Rec. opt.) for recording.

11 (edited by jiw 2019-08-30 19:03:07)

Re: DIGICheck 0.73 on macOS 10.14.5 shows no data recorded by ADI-2 DAC

I did some further testing. Turning the recordings into 16 bit integer to compare with the 16 bit test produces non-zero but identical sums of square differences. However, the sum of square differences of the recordings for the first complete bit test is 0.

Thus, as stated previously, there are no errors using either Optical or USB (Rec. opt.) for recording.