Greetings. I would like to try to change the sound card from internal (Hifiberry Stage) to external (Focusrite Scarlett Solo) to improve the sound quality. The problem is that the Focusrite only powers itself via the USB cable connected to Zynthian. I have the impression, however, that in this way (via USB) no power reaches the Focusrite (which in fact does not turn on) and therefore Zynthian does not see the external card. Thanks for your help
You may have a device that is not supported by Linux or that requires extra drivers. The Focusrite Scarlett Solo is not USB class compliant so requires drivers to work on any operating system. This discussion suggests that earlier models may have Linux drivers but later (v3) do not. With it plugged in, run lsusb from a command prompt and post the results here.
BTW - what improvement of sound quality do you expect? Is there a specific issue with the Hifiberry Stage you are trying to resolve? It is useful feedback in case we need to improve the ZynADAC derivative in the future.
Thanks Riban for your reply. These are the LSUSB results:
root@zynthian://zynthian# lsusb
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 2109:3431 VIA Labs, Inc. Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Furthermore, I do not have an operating problem but by comparing the sound, for example of Pianoteq, processed by the internal and external sound card, clear differences in timbre emerge. The sound of the piano converted by Hifiberry appears thinner, less full… in short, of lower quality than that generated by an external card.
root@zynthian://zynthian#
lsusb isn’t showing anything plugged in. Is the Focusrite plugged in and turned on?
How are you comparing internal / external if you don’t have the Focusrite working?
I specified in the first message that “The problem is that the Focusrite only powers itself via the USB cable connected to Zynthian. I have the impression, however, that in this way (via USB) no power reaches the Focusrite (which in fact does not turn on) and therefore Zynthian does not see the external card.”
That’s why it doesn’t work … but how can I fix it?
I made the comparison between the pianoteq sound from a windows app on an external card and the sound from zynthian with an internal card.
Raspberry Pi can power external equipment via USB, indeed I power an external MIDI interface and have used a USB audio device too. You need to be sure that the power supply has sufficient power / current rating. 3A should do it. I would expect the USB device to show to lsusb, even if it didn’t appear to power up. Devices that need drivers need to present themselves via USB so that the computer can identify them. Some may require drivers to enable them and may appear unpowered until that has happened. The USB MIDI device I use (MIDISport) is like that, appearing dead until the driver loads.
Pianoteq on Windows is likely to be configured with a higher internal sample rate, e.g. 44100 whereas Zynthian configures Pianoteq with a lower internal samplerate, e.g. 22050 to reduce CPU usage. This will result in a duller sound as it will roll off at about 10kHz. I doubt you will observe much (if any) improvement with the Focusrite. They are good soundcards but so is the Hifiberry.
You can access Pianoteq GUI via VNC and change its internal sample rate to a higher value to hear if it compares with your Windows test. It is likely to start clicking as it triggers xruns but you may be able to satisfy yourself whether the built-in soundcard is causing degradation.
Also a strong Power Supply and a heavy USB cable are needed for not suffering from underpower.