Topic: Raspberry Pi 4 via USB and ADI-2 DAC

My results (using Roon/Ropieee) so far are good. No glitches, no crackles, no problems playing, up to DSD256 DoP. Sound is good in my non-audiophile ears and setup. As good as the Squeezebox and Sonore microRendu (which I sold). There doesn't seem to be a difference between my Raspi 3 + Digiberry via coax. I grouped both devices in Roon, and multiple blind tests proved for me there wasn't. First test I thought so (or I just guessed right) but the two other tests showed a random result. Oh, and I also added a screen, so I can see the album cover, and it's almost like having a Squeezebox.

Only one odd thing so far (and I'm not sure whether this is a Raspberry or ADI2 related problem): when the DAC has just started up the first sound I hear when I start playing is a click. Everything I play afterwards is fine. When I turn off the DAC and try again to test it, the click sometimes occurs, and sometimes doesn't. I always hear the click in the morning (when it's been turned off all night). The Raspi is always on. The Raspi 3 + Digiberry via coax didn't click, so it might be USB related?

I'm not expecting RME to find a solution for devices they don't sell, but I'm looking for clues here. I have daily contact with the Ropieee developer, and we're trying to find the culprit. Any suggestions what I could try or check?

2

Re: Raspberry Pi 4 via USB and ADI-2 DAC

Have a look at the unit's sample rate - does it change?

Regards
Matthias Carstens
RME

3 (edited by Trojka 2019-08-05 05:46:56)

Re: Raspberry Pi 4 via USB and ADI-2 DAC

Yeah, now that I think of it, the last sample rate is usually 48Khz (TV, opt) before I turn it off. Then the first music I play via Raspi 4/USB is 44 or 96. Then I can switch without clicks to DSD256 to 44 to 96 to DSD128. So it might be related to the opt/usb switch in conjunction with the sample rate switch.

Re: Raspberry Pi 4 via USB and ADI-2 DAC

Is this expected behaviour?

5

Re: Raspberry Pi 4 via USB and ADI-2 DAC

A sample rate change can always cause a click, and the reason behind it can be different things. As you can easily try yourself, changing the sample rate as such does not cause a click, so most probably there comes a bunch of resetting/initializing data in that 'frist play' moment that cause this.

Regards
Matthias Carstens
RME

6 (edited by Curt962 2019-08-06 14:58:20)

Re: Raspberry Pi 4 via USB and ADI-2 DAC

Hey Trojka!   Welcome Back!  Thought We'd lost you..

Great to hear that your new RasPi is up, and running smoothly.    My Eldest Son, and I are ready to Pull the Trigger, and build one up.   Only matter now is Form Factor, and Screen Size.   Preferably a Screen with a better Vertical Viewing Angle than my beloved SBTs. 

Enjoy!!

Curt

7 (edited by Trojka 2019-08-06 20:44:57)

Re: Raspberry Pi 4 via USB and ADI-2 DAC

Ah cooll! Just consider it a fun side project, and keep your Squeezeboxes. :-) By all means, get the 4! It's about the same price as the 3, but no shared hub for USB and network.

You don't have much choice regarding small touch screens. I simply bought the Raspberry 7" touch screen. Because I use Roon, I could install the Ropieee image by Spockfish (also Dutch). Roon by itself is quite expensive, but I love how it organized my collection and I can't go back. For you I would advise to investigate what the non-Roon possibilities are: Squeezelite probably, but I'm not sure what your screen options will be.   

In my setup angle doesn't matter: I bought a case sturdy enough to place it fully upright. It's very clear and visibility is good. Titles are kinda hard to read from listening position, but the album cover is instantly recognizable.

https://tjarkobusink.files.wordpress.com/2019/08/whatsapp-image-2019-07-28-at-17.51.23.jpeg

Re: Raspberry Pi 4 via USB and ADI-2 DAC

I'm using a RPi4 with piCorePlayer upsampling everything to 768kHz. Squeezelite is much more responsive on the RPi4 than on the RPi3 it replaced.

9 (edited by Trojka 2019-08-07 16:32:26)

Re: Raspberry Pi 4 via USB and ADI-2 DAC

MC wrote:

A sample rate change can always cause a click, and the reason behind it can be different things. As you can easily try yourself, changing the sample rate as such does not cause a click, so most probably there comes a bunch of resetting/initializing data in that 'frist play' moment that cause this.

Initial starting position for USB from startup seems to be 768Khz. So in theory there's always a sample rate change.

Re: Raspberry Pi 4 via USB and ADI-2 DAC

badboygolf16v wrote:

I'm using a RPi4 with piCorePlayer upsampling everything to 768kHz. Squeezelite is much more responsive on the RPi4 than on the RPi3 it replaced.

Not sure why you upsample.

Only FYI: upsampling gives no better sound, the quality is fixed by the quality of the source, which can't be further enhanced.
"it is like it is".

BR
Ramses
X10SRi-F, Win7 Prof, Cubase 9.5, UFX+, Octamic XTC, ADI-2 Pro FS BE/DAC, RayDAT, ARC USB

11

Re: Raspberry Pi 4 via USB and ADI-2 DAC

He's not upsampling. Mac OS and it seems the Raspi as well always start with the highest sample rate available, typical for Class Compliant operation. And that is 768 kHz with the DAC.

Regards
Matthias Carstens
RME

Re: Raspberry Pi 4 via USB and ADI-2 DAC

The internet is full of articles of pictures that make you believe that upsampling 'interpolates between the dots of 44100 samples per second'. I always thought it worked that way until I read some scientific articles on the subject that somehow made more sense to me. The commonly spread truth about upsampling was not how it worked, according to these people. The general idea that 192Khz is better, was open for debate. Now, I know too little about it to start a debate about it (we have enough debates on this forum). But eventually it led to me enjoying my 16/44 albums again without worrying it was inferior. Like Curt, I just enjoy listening to music. To me, listening to a well recorded album in 16/44 (even when it's DR9!) is always better than listening to Diane Krall just because it's 24/192 (believe me, I know people who only listen to that music because of the sound quality).

13 (edited by Trojka 2019-08-07 20:35:15)

Re: Raspberry Pi 4 via USB and ADI-2 DAC

MC wrote:

He's not upsampling. Mac OS and it seems the Raspi as well always start with the highest sample rate available, typical for Class Compliant operation. And that is 768 kHz with the DAC.

Correct, I'm not. badboygolf16v is though, via software in the Raspberry.

Now that click...I still haven't found why it sometimes starts with a click and most of the times it doesn't. No big problem of course, just the nerd part in me wants to find out when and why. big_smile

14 (edited by badboygolf16v 2019-08-07 21:03:25)

Re: Raspberry Pi 4 via USB and ADI-2 DAC

I am asyncronously resampling/upsampling everything to 768kHz using Squeezelite soxr libraries. 

Why? Why not!? Because I can. ;-) I saw Miska of HQPlayer doing it.

Does it make an audible difference. I think not. I am aware of this.

That's not the point of my post though, the point is that the RPi4 is much quicker than the RPi3 when doing the SRC conversion.

Re: Raspberry Pi 4 via USB and ADI-2 DAC

I'm beginning to believe it's not a sample rate conversion, but the last state of the Roon software. Was it stopped or playing when I turned off the DAC? I need to test it.

Re: Raspberry Pi 4 via USB and ADI-2 DAC

There was a Force Volume option in the Ropieee software I had turned on (I misinterpreted its function). After turning it off, the occasional click is gone. Problem solved.