DietPi Pops & Stutters on Allo USBridge Signature

General Discussion
1

Greetings All,

New here and new to Raspberry Pi world. :slight_smile:

This may have been covered else wher eso if so apologies and please point me to the appropriate thread or category. I have recently purchased an Allo USBridge Signature RPi unit with DietPi pre-installed (I am running Squeezelite Player on it for connection to my LMS Music Server). Couple of things I’ve detected (one of which I know has been raised previously by other users of this device on Allo forums). My Allo unit is connected via USB to a Cirrus ESS Sabre 32-bit Reference DAC (in an Oppo BDP-105D):

  1. I get very occasional pops and crackles but they are rare, nearly always playing DSD files, otherwise on the occasional 24/176 or 24/192 FLAC file. Previously it was suggested only certain versions of DietPi would okay to use with Allo devices (my player has arrived from Allo with v6.26.3 on it). Could the O/S version be causing the pops/crackles, or is this likely related to the CPU Governor Setting (currently on the default auto setting)?

  2. When playing DSD I get pauses/stutters - there is no missing audio but instead a 1 second or so ‘blank’ (like someone has cut the audio stream with scissors and slightly pulled the two halves apart creating a gap). With DSD64 (the majority of my DSF tracks) it typically happens once during the track. However with DSD128 it will do it 2-3 times during playback. My suspicion is this is a CPU Governor Setting issue as it’s just a bottleneck effect on the data throughput and I need to push the CPU to permanently be set to ‘performance’? Is setting Performance via teh Allo/DietPi web GUI the right way to do this, or should you do so directly in a system boot-up config file or similar?

Appreciate any feedback or pointers to relevant discussions.

TIA

2

HI buddy, following up on this as of now I will let you once I try something similar.

Regards,
Bave Smith

3

Thanks Bave!

FWIW for now I have set it to ‘performance’ in the DietPi GUI - and that seems to have resolved the worst of it (no pauses/gaps/stutters and haven’t noticed any obvious pops or crackles) - but I have not done a good session of serious/critical listening since (with 24/176 & 24/192 FLAC and DSD64 & DSD128 files) to validate its definitely resolved for good.

However I have not attempted to upgrade the O/S version as yet (was planning to get a spare SD Card and back-up current config before doing anything else - in case it all goes wrong then I can just swap out the cards to get back up and running - assume this is pretty standard practice with RPi devices…).

:slight_smile:

4

P.S. Also still trying to determine if I should set that CPU setting in a config file or somewhere to ensure it is the default for wherever the system restarts from being powered off?

5

Hi,

you can use dietpi-config > Performance Options to tweak cpu values

6

Allo has shipped a special driver for the Allo USBridge Signature which has been implemented with DietPi v6.27. Did you upgrade to current version? During update you should see some output about this driver being installed.

7

Hi Michalng - no not as yet - still on the v6.26.3 that the unit shipped with… Was going to make a back up SD Card of the O/S before i did the upgrade (and haven’t yet)… Will do so and try the upgrade to v6.27.

Cheers

8

P.S. is the current version now actually v6.28, assume drivers are included in all post v6.27 versions? I’ve seen reports elsewhere of Allo USBridge Signature users having implemented v6.28 (already)?

9

Thanks Joulinar - is this a command line function via root (to edit config)? Still learning my navigation around RPi O/S’s… Quick search of forum I couldn’t find an obvious tutorial or basic guide?

Or are you referring to this: DietPi-Config | Feature rich config tool for your device

P.S. I’ve seen some USBridge Signature users set a fixed frequency, and some overclock it to 800 using Arm_Frequency value (and Force_Turbo).

10

Hi,

DietPi offers a lot of scripts and user tools to manage majority of settings on the systems. dietpi-config is one of them. It can be used to set CPU values, overclocking aso. Just have a look to the performance options.

11

And yes, the updated USBridgeSig drivers are included in v6.28 and the current RPi images already. Also they will be reinstalled automatically on RPi kernel upgrades. But note that Allo only compiled them for RPi2/3/4, not RPi1/Zero.

12

Thanks Joulinar - will do! :sunglasses:

Great - thanks MichaIng - I will get on with making a backup of the O/S SD Card then doing the upgrade. :slight_smile:

Once I’ve done all the above (update to v6.28 and then perfomance options with dietpi-config ) I will do some more listening/testing to verify my issues have definitely been eliminated (likely in about 3-4 weeks, schedule permitting).

Thanks Again!