[PROBLEM] Moode audio stops but moode is still playing files?

[mikeburnsnz]

Hi there everyone. I have done a bit of searching to solve a new problem I have started having with Moode. Could not find anything so figured I would ask here.

My setup details are:
RPi 4
Moode Audio 6.5.2 with a 1TB SSD drive (with locally stored music files) connected via USB port on RPI.
Sends audio signal to SMSL SU-8 DAC via USB
DAC to preamp, preamp to poweramp, poweramp to speakers.

My issue has seemingly just started after adding new files my hard drive (this problem was not apparent prior to adding new music files). 

Basically I start up Moode and play a file. Sometimes the file plays as normal but after a random amount of time (normally 25-30secs of playback) the sound just stops coming out of my stereo. Moode shows the file is still playing, volume at 100 and no obvious errors. If I choose another file it plays on Moode but I get zero sound. If I restart the pi it repeats the issue again. After some time the sound seems to come back but then it cuts out again.

I am having no problems playing music from my laptop via usb through the dac, so it seems to be a moode/DAC issue. It may have something to do with cycling through inputs on the dac (which powers down the other inputs e.g. USB if I go to optical etc). I have had an error in the past where it seems to take a little while for the RPi to recognise the newly powered usb input on the dac after cycling through the inputs to another option and whilst having moode on. It normally gives me an MPD error in this state though... this new issue doesn't give me the mpd error.

The lack of audio doesn't seem file related or file type related. Moode continues to appear to be running seamlessly, just 0 audio comes out. I can search for files, display cover art etc. Just no sound.

Would anyone have any thoughts on what might be happening? It has basically rendered the playing locally stored music option useless.

Thanks very much.

[Tim Curtis]

It sounds like a USB audio hot-plug issue or possibly something to do with the Pi-4B USB implementation which is quite different from earlier Pi's. IME USB audio hot-plug on Raspbian has been problematic.

Are u using the USB2 or USB3 port for the DAC?
Try swapping in a Pi-3B+

[mikeburnsnz]

It sounds like a USB audio hot-plug issue or possibly something to do with the Pi-4B USB implementation which is quite different from earlier Pi's. IME USB audio hot-plug on Raspbian has been problematic.

Are u using the USB2 or USB3 port for the DAC?
Try swapping in a Pi-3B+

Hi Tim, thanks for the post. Unfortunately I do not have a Pi3 (the 4 was my first pi). Ideally I want to use the 4 as it is a faster computer and doesn't have the choke point in the usb that the 3 does... I get the idea of the hot usb plug, that makes sense, but I wonder if it is the dac having the issue or the pi/moode having the issue? Seems very odd that the music appears to be playing fine, with the counter moving along and everything seeming fine, but no sound, like it is muted.

I am using the USB2 port currently. Do you recommend the USB3 instead? 

The problem is weird as the sound works fine for a little while, and prior to the added songs it worked absolutely fine (minus the slight glitch when cycling inputs, but that rectified itself after a short period - 30 secs or so, or by refreshing moode). It is odd how it just stopped working. Nothing else was changed in the settings and I removed the drive with the pi powered off to avoid any errors.

[mikeburnsnz]

OK so a little bit further experimentation may have fixed the issue (cross fingers). I thought about the order I turned the pi back on in with the dac. Seems the trick is ensuring the dac is turned on and is set to the usb input when the rpi gets turned on and moode starts. It is like the pi wasn't seeing the dac (or the dac wasn't picking up the signal from the pi). Either way that seems to have fixed the issue. Your call on the hot plug was what led me to think about the signal at power up. Thanks Tim.

Hopefully it doesn't randomly appear again.