Raspberry pi4 with USB

[spaace]

Hi,

I wanted a 4k system for movies, so I upgraded my existing raspberry pi3 HAT system to a raspberry pi4.

I havent got a dedicated a audio HAT with the new pi since i assume that the old USB interface problems are not present anymore.

(Please do let me know if this is correct)

But when i try to play the music through USB, via Benchmark DAC3 USB interface, nothing seems to come out, though the DAC3 shows DSD 48 Hz + DSD 2x

Anyone got this working?

Rgds
Arun

ps : I use Kodi as my player and the audio interface options shows ALSA Benchmark USB 1.0 S/PDIF and analog devices amongst it entries, which indicates the DAC is identified correctly but that seems to be about it

I do see this error in dmesg " usb 1-1.4: 10:0: cannot get min/max values for control 2 (id 10)"

lsusb -v output shows the device too

 

[spaace]

Fixed it with input from the benchmark folks.

Apparently the DAC3 has to be put in USB2 mode.

This is achieved by pressing the USB button on the remote or the device for 3 seconds.

Once this is done, the audio interface correctly recognizes it as USB 2.0 device and displays it accordingly

Thank you

 

[spaace]

So the only doubt remaining is if a dedicated HAT needs to be used with the new rpi or not

Data in this forum suggests USB might be good enough and using HAT has problems with cooling / power.

I am also using a standard pi4 charger - I would like to know if this needs to be upgraded.


Thanks in advance

 

[Music1969]

So the only doubt remaining is if a dedicated HAT needs to be used with the new rpi or not

Thanks in advance

No need.

As you wrote, the previous RPi model issues with USB output (mostly with higher sample rates) are a non-issue with RPi4

Are you using balanced output from Benchmark?

 

[spaace]

Thanks for replying. Yes iam using the balanced outs from the DAC3.


I was not able to find a technical source which described the rpi4 audio.

I remember reading up on the problems with USB and how the i2s with HAT solved it, which really explained things well.

If you have any such write ups handy on the new rpi4 audio subsystem improvements, please do share it - as i would like to understand what has changed


I assume there are no official reviews here on the forum either with rpi4 USB interface either?

What about the power source ? Is the standard one good enough?

Rgds
Arun

 

[Music1969]

I was not able to find a technical source which described the new rpi audio improvements.

There were pops and clicks with previous RPi models at higher sample rates, because ethernet and USB shared same bus.

This changed with RPi4 - no longer share same bus, so no longer any pops/clicks, even at PCM768kHz sample rate

It wasn't a focused attempt by Raspberry to improve audio specifically - but it improved for some people, as a by-prodoct of this change

 

[Music1969]

What about the power source ? Is the standard one good enough?

If using Benchmark balanced outputs, I wouldn't bother - stick to stock power source