[PROBLEM] Popping sound during playback

[placebo-fi]

Hi Tim,

If I unplug my USB DAC the output looks like this

Code:

pi@moode:~ $ /var/www/command/util.sh get-alsavol PCM
0%

I think the reason why there's no output is that my DAC has no volume control at all. Here's the output from running "alsamixer"

Code:

lqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq AlsaMixer v1.1.3 qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqk
x Card: Schiit USB Audio Device                        F1:  Help               x
x Chip: USB Mixer                                      F2:  System information x
x View: F3:[Playback] F4: Capture  F5: All             F6:  Select sound card  x
x Item: PCM                                            Esc: Exit               x
x                                                                              x
x                                                                              x
x                                                                              x
x                                                                              x
x                                                                              x
x                                                                              x
x                                                                              x
x                        lqqk                     lqqk                         x
x                        xOOx                     xOOx                         x
x                        mqqj                     mqqj                         x
x             <          PCM           >Clock Source 18 Validity               x
x                                                                              x
x                                                                              x
x                                                                              x
x                                                                              x
x                                                                              x
x                                                                              x
x                                                                              x
mqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqj

As you can see, there's no PCM volume control on this device. So I believe the build is not broken.

[rikardo1979]

Hi!

I experience a very loud peak noise between two songs playing from a playlist on an USB-Stick. It does not happen all the time, but quite often. This is not just an annoying click, but it is so loud that it makes me jump.

I checked the mp3 files and they seem to be fine.

I appreciate the sound quality with moode, but this makes it unusable for me. I hope there is a solution to this problem.
  
Here is the info about my installation (please let me know if you need more):

Release Information

• Release: 4.1 2018-04-02 View relnotes
  
• Update: (None)
  

Platform Information

• Raspbian ver: 9.4
  
• Linux kernel: 4.14.32-v7+, armv7l
  
• Hdwr revision: Pi-3B 1GB v1.2
  
• MPD version: 0.20.18
  
  

DSP OPERATIONS
Resampling: off
Crossfeed: off
Equalizer: Graphic EQ: (Hi-Lo Boost), Parametric EQ: (off}
Crossfade: 10 seconds
Other: Volume normalize (no}, Replaygain (off)
Chip options: FIR interpolation with de-emphasis, gain=0 dB, boost=0 dB
Volume ctl: Software (MPD 32-bit float with dither)

AUDIO DEVICE
Device: HiFiBerry DAC+ Pro
Chip: Burr Brown PCM5122
Architecture: Sigma/Delta Advanced Segment 24 bit 192 kHz
Interface: I2S

I have merged your thread into this one with same topic.

[Mullet]

I'm having somewhat similar issues (glitches and small pops every few seconds), though my configuration is somewhat different (pi 4, minidsp USB input as the dac). 

I have tried the cpu governor, 32/64 bit kernel and turned off Bluetooth with no changes. 

My original though was noise from the amps, but I used host USB power for my pi 4 from the minidsp preamp with no change.

It does seem to be slightly sample rate dependant, with upsampling via the resample making it occur even more frequently. That may just be a perception thing though and not real.

Shouod I start a new thread?

I wouldn't...

I'm having the same issue with 6.3. I also have an earlier version of MoOde that seems to work perfectly with same or similar settings. The pops are random and I have to use a track that is acoustic with not a lot going on to hear the pop. As far as settings... I'm using some config.txt tweaks...

disable_splash=1
hdmi_drive=2
dtparam=i2c_arm=on
dtparam=i2s=off
dtparam=audio=on
arm_freq=1000
sdram_freq=500
core_freq=400
gpu_freq=300
over_voltage=-3
over_voltage_sdram=-3
start_x=0
max_usb_current=1
gpu_mem=16
dtoverlay=pi3-disable-bt

Also have 32bit kernel. BT turned off. USB DAC. Default MPD version. 16384 KB for buffer at 30%. Performance. HDMI turned off. Ethernet fix. USB fix.

My USB transport is an Amanero USB to i2s.

Any ideas on what to look at next?

Thanks,
Mullet

[Mullet]

I'm having somewhat similar issues (glitches and small pops every few seconds), though my configuration is somewhat different (pi 4, minidsp USB input as the dac). 

I have tried the cpu governor, 32/64 bit kernel and turned off Bluetooth with no changes. 

My original though was noise from the amps, but I used host USB power for my pi 4 from the minidsp preamp with no change.

It does seem to be slightly sample rate dependant, with upsampling via the resample making it occur even more frequently. That may just be a perception thing though and not real.

Shouod I start a new thread?

I wouldn't...

I'm having the same issue with 6.3. I also have an earlier version of MoOde that seems to work perfectly with same or similar settings. The pops are random and I have to use a track that is acoustic with not a lot going on to hear the pop. As far as settings... I'm using some config.txt tweaks...

disable_splash=1
hdmi_drive=2
dtparam=i2c_arm=on
dtparam=i2s=off
dtparam=audio=on
arm_freq=1000
sdram_freq=500
core_freq=400
gpu_freq=300
over_voltage=-3
over_voltage_sdram=-3
start_x=0
max_usb_current=1
gpu_mem=16
dtoverlay=pi3-disable-bt

Also have 32bit kernel. BT turned off. USB DAC. Default MPD version. 16384 KB for buffer at 30%. Performance. HDMI turned off. Ethernet fix. USB fix.

My USB transport is an Amanero USB to i2s.

Any ideas on what to look at next?

Thanks,
Mullet

[Mullet]

So after testing with another USB DAC I'm not having intermittent popping issues. The only difference I can think of is the previous USB DAC is UAC2 (Amanero), which is also being powered by the Pi. With this other DAC it's UAC1 and USB is being powered by separate 5v supply. UAC2 fix didn't seem to fix pops with first DAC. Hrmmmm.

[DRONE7]

(Amanero)..... what version ?

https://github.com/lintweaker/xmos-native-dsd/issues/12
https://www.diyaudio.com/forums/digital-...o-usb.html

[Tim Curtis]

So after testing with another USB DAC I'm not having intermittent popping issues. The only difference I can think of is the previous USB DAC is UAC2 (Amanero), which is also being powered by the Pi. With this other DAC it's UAC1 and USB is being powered by separate 5v supply. UAC2 fix didn't seem to fix pops with first DAC. Hrmmmm.

Linux and UAC2 audio interfaces continue to be a challenge. These same audio distortions were present when I began working with Linux audio way back in 2013. There is no magic fix.

Have a look at some of the Linux kernel USB audio quirks
https://github.com/raspberrypi/linux/blo...b/quirks.c
https://github.com/raspberrypi/linux/blo...ks-table.h

To quote the maintainer,  Takashi Iwai,

"* In a perfect world, this file would be empty." 

-Tim

[TheOldPresbyope]

Noted in passing...'Amanero' appears in the referenced quirks files.

[Tim Curtis]

Even if a device is listed in the quirks there is no guarantee that its a universal fix due to differences in device firmware revisions where one or more of the revs may have bugs. There are also reports of audio glitch issues with kernel 4.19.y and certain USB DAC's that may be caused by bugs in the kernel usb audio driver.

[TheOldPresbyope]

I was being too economical with my words. The point is that the DAC is already known to be a problem device. 

Likely the quirks maintainer depends on others to test and report specific devices and both groups likely trail behind the kernel developers.