Schiit Modi 1st gen not working w Pi3

[TheJagWar]

Hi all,

First id like to commend the runeaudio developers and community for a great piece of software!

As for my issue, I've recently downloaded the latest runeaudio image and placed it on my RPi 3, and have a Schiit Modi and Magni for my DAC and amp respectively (both are 1st gen devices). Now, under output, the Modi wouldn't appear for a while (just the RPi Analog and HDMI), but after tinkering around with various settings (can't recall which ones), my Schiit Modi appeared as a device and everything worked perfectly.

I then had to unplug and plug the pi back in and now the Schiit Modi isn't appearing as an output option at all. I've tried tinkering again with the settings but to no use. I've read about uncommenting a line for the hifiberry dac device tree in config.txt (which I realize is different than my modi but thought I'd give it a try) and still no use.

Is there something I'm missing to make my modi work again? It was somehow recognized and played beautifully until I had to unplug my pi any help is much appreciated!

Thanks!

[hondagx35]

Hi TheJagWar,

your DAC is connected via USB and should be recognized without any modifications.

Please post the debug info from your Pi with the DAC plugged in.
You also can try my latest image from here.

Frank

[TheJagWar]

Hi Frank,

I tried the new 0.4 beta image you have on your google drive (thanks for the link!) but to no use. I'm not sure what I should select under the I2S kernel module (tried default and hifiberry DAC, etc without any luck). Either way, leaving it with default settings only reveals the raspberry's analog and HDMI outputs as options but no schiit modi DAC.

Here's a link to the debug info: https://pastebin.com/NuYH5H5y

Looking at the debug info, under USB devices, I can see my sandisk cruzer but cant make out which device represents my Schiit Modi (or if its even recognized).

I really appreciate your help!

Thanks

[hondagx35]

Hi TheJagWar,

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[    5.558245] usb 1-1-port4: Cannot enable. Maybe the USB cable is bad?

I think this is part of your problem.
Please check the cable or try a powered USB hub.

what I should select under the I2S kernel module

Nothing, because you are not using a I2S device. This option is only for I2S DAC hats like Hifiberryand others.

Frank

[TheJagWar]

Yes I just realized about and read into the I2S interface and what it is- thanks for pointing that out and eyeing the USB issue in the debug! I tried an externally powered USB hub but received a host of similar errors for each additional USB port added so that didn't work out too well.

I ended up unplugging my thumb drive and booting the pi with just my schiit plugged in and it worked! Previously I had the thumb drive in there prior to booting so I'm not sure if that was impacting the amount of power going to the Modi. I then plugged the thumb drive after booting and it seems to be working well.

Two last questions for you:

1) do you have any recommendations for a good externally powered USB hub to power the Modi?
2) what are your thoughts on external DACs (like the modi) vs one interfacing with the pi via I2S (something like the allo boss).
- reason I ask is because I'm not sure how much of an impact sharing the USB and Ethernet ports by the same controller on the pi ultimately impacts bandwidth and sound quality going to the Schiit Modi.
-- I've also read that clocks and other board peripherals used by external DACs seem to be superior to those used by I2S DACs for the pi resulting in better sound quality so...

Basically I'm not sure which argument has a broader impact on audio quality.

Thanks so much for your help, Frank! Really appreciate it!

[TheJagWar]

Anyone have recommendations on the 2 questions above?

Thanks!

[janui]

Hi TheJagWar,
1). See this list: https://elinux.org/RPi_Powered_USB_Hubs. But almost any will work fine. When you buy one, check that the power supply delivers enough current. A custom USB cable between the Pi and the HUB, with the power (red) wire disconnected, is advisable to solve the back-feeding power problem (preventing the hub powering the Pi). There are lots of discussions about the need for a very high quality power supply for your Dac (here powered via the HUB). I wouldn’t worry about it, your Dac should solve any power noise problems (it expects to be powered via an USB port). If it is a problem then better to solve it later when everything else works.
2). There are lots of discussions about on-board oscillators and synchronous/asynchronous signal processing, almost always related to jitter. But measurement information is almost impossible to find. Take a look here: http://archimago.blogspot.nl/2016/10/me ... berry.html This should help you understand/decide.
janui

[TheJagWar]

Thanks for the recommendations janui!

I'm sad to say that after a reboot, I'm having the same issues with rune audio not seeing the schiit modi as an output option again.

I've upgraded the pi 3's power supply to the one provided by cana and introduced a powered hub for the schiit to no avail. I've also tried powering it on with the modi being the only USB peripheral plugged in but nothing happens.

Interestingly if I power on the pi 3 with no peripherals plugged in and then plug the modi into the USB port, the whole system crashes and isn't accessible from the .local interface (haven't tried ssh-ing into it though).

I can't help but wonder if the schiit modi's use of the USB Audio 1 standard over USB 2 has anything to do with this inconsistency. Does the pi have difficulty recognizing this standard? I'd just like for this thing to finally work again

Thanks for all of your help!

[janui]

Hi TheJagWar,
Seen photos of the dac, power should not a problem is seems only to need 120mA, that should work without a Powered Hub. Your thoughts about drivers could be correct, you could attempt to install the package 'alsa-firmware'. It is not included on my Pi3 image. This seems to contain the alsa drivers included in the basic installation plus some extra's and features for hot-plugable (on demand) use . Make a backup/copy of your sd-card first!!! Then log in via SSH and try this:

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pacman -S alsa-firmware

It will tell you if it already is installed, choose y/n to continue/abort. Reboot and try again.
If it doesn’t help, best to remove it with

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pacman -Rs alsa-firmware

janui

[TheJagWar]

Thanks for the suggestion, janui! I tried it but it still doesn't show the Modi as an output option.

Is there a way to force the pi into using the USB 1 audio standard that I can add to the cmdline?