1 (edited by jlm70 2021-06-02 16:17:34)

Topic: ADI-2 DAC fs: sound gaps over 384kbps

Dear friends,
I'm suffering a problem with my chain:
MacOS Big Sur 11.4 - Audirvana (or Amazon HD) - ADI2DACfs - SMSL DA-9 - JohnBlu JB3 speakers.

The problem replicates whatever software player I use if the output resolution is over 384kpbs.
Therefore I've fixed Audirvana not to go over that maximum res (except if DSD256 files are played).

What happens if >384kbps?
I always get gaps in the music, sort of stuttering, from time to time (but always).

I'm using the original RME USB cable via a thunderbolt-to-usb hub (given the mac has no usb-a plugs).
A 768KHz/32 stream should occupy about 50Mbps, so well below the theoretical 480Mbps USB2.0 limit.
I've already tried to use different USB ports.

Has anyone ever suffered such a problem? Any idea?

PS. for the rest I can only be extraordinary happy with this awesome DAC / engineering opus. Think I'll stick to RME forever, even not being a pro :-)

2

Re: ADI-2 DAC fs: sound gaps over 384kbps

I don't have Audirvana, so please check if you can set a buffer size for audio in there, and set it more high. This might fix the issue. If not then the TB to USB hub might be the reason, some of them have mediocre performance for USB. For a test get yourself a simple USB-C to USB-A adapter or USB-C to USB-B cable and run the ADI directly from the Mac.

Regards
Matthias Carstens
RME

Re: ADI-2 DAC fs: sound gaps over 384kbps

Thanks for the prompt answer... I... work too much and I forgot I did this exact question 3 weeks ago... O_o...

Anyhow... yes, I had to buy other adaptors to understand if the TB-USB connection caused the issue.
So I  tried 3 different connections:
(1) via "original" Benq monitor USB hub (thunderbolt enabled)
(2) via Amazon USB 3.1 USB hub
(3) via new VAVA USB 3.1+HDMI hub (without any other connected device, no monitor/hdmi connected).

No one works (and I need an interface to adapt the USB-C Macbook plug to a traditional USB-A).
(the only try I miss is to purchase a direct usb-c to usb-b cable... but that would even cause other problems 'cos in normal usage I've no spare usb-c connectors to use).

Within Apple MIDI settings app the selected clock source is "DEFAULT", and I cannot change it (I thought about a potential clock problem... and I do not know if DEFAULT... uses the external/ADI clock...).

About Audirvana: I can force the output resolution to <=384kbps, and in this case the "chain" works.
Obviously except any other HD track that goes over this limit. For instance if I play DSD256 files... these ones need overcoming the 384kpbs limit (the file needs a 705,6kbps res) and cause the usual gaps.
I'll record a video to better (and clearly) show the problem...

4 (edited by jlm70 2021-06-03 14:52:36)

Re: ADI-2 DAC fs: sound gaps over 384kbps

Here's a youtube video to show the problem: https://youtu.be/65C_CXCfsxs
Sample song: Beatles | Abbey Road (remastered) | Come together (2019 mix) | DSD256

The problem appears to any other DSD256 song. Or even to any other FLAC, if upsampled by Audirvana over the 384Khz threshold.
Or even if the song is played by Amazon HD and the Apple MIDI setting for the ADI-2 DAC is set over 384Khz (eg. 768Khz): in this case the system allows Amazon HD to use maximum res and AMHD upsamples to 768... giving the same problem.

5 (edited by jlm70 2021-06-03 14:56:59)

Re: ADI-2 DAC fs: sound gaps over 384kbps

About the other question, Matthias:
"The Benq does not have Thunderbolt.
The MacBook has 4 USB-C ports. Did you try them all? They behave differently."

Benq: to be precise I've a Benq PD2710QC display that uses a single USB-C connection to transport video, power delivery, ethernet and a 4 ports USB hub. This port has been connecetd with an hi-quality magnetic attachment that "uses" two ports on my Macbook Pro (8-core Intel i9, 32GB RAM).
Then on the other 2 ports I've an NVME 2TB drive (always connected) and a Logitech Brio 4K webcam.

My audio trials tested a couple of USB-C ports (with only the SSD attached on another port, as the SSD is "part of my system").

The RME audio usage shouldn't be that demanding, maxing out at about 50mbps at max resolution... no?
Might it be a clock problem? Or... a faulty USB-A/USB-B cable? (it's the original RME one... but 50mbps shouldn't be an issue for a 480mbps capable cable).

Thanks