Improvement advise on my current setup

[wkloppen]

Hello to all,

I'm looking for some improvement advise on my current setup.
My basic sound chain looks like this: Qobuz > Raspberry pi 4b (8gb mem) > UPMPDCLI / MPD > USB DAC (smsl sanskrit 10-edition mk-III > Wolverine amp > Kef reference model 3's from the nineties.
The raspberry (and dac via usb) are powered by an 5volt IFI power supply.
My mpd.conf and asound.conf look like this:

mpd.conf

audio_output {
        type            "alsa"
        name            "SMSL USB AUDIO"
        device          "hw:0,0"
        mixer_type      "none"
        mixer_control   "SMSL USB AUDIO "
        auto_resample   "no"
        auto_channels   "no"
        auto_format     "no"
#       mixer_index     "0"
}

asound.conf

pcm.!default {
        type hw
        card 0
        device 0
        periods 2
        auto_resample no
        auto_format no
        auto_channels no
        defaults.pcm.rate_converter samplerate_best
#        buffer_size 8192
#        period_size 2048
#        period_time 200000
}

pcm.!default {
    type plug
    slave {
        pcm "hw:0,0"                # Replace with your DSD-capable DAC device
        format DSD_U32_BE           # Set the format to DSD 32-bit Big Endian
        rate 176400                 # Use the correct rate for DSD64 (adjust for DSD128, etc.)
        channels 2                  # Stereo output
    }
}

ctl.!default {
        type hw
        card 0
}

I further more have set the I/O scheduler to none

root@DietPi:~# cat /sys/block/mmcblk0/queue/scheduler
[none] mq-deadline kyber

I'm using upmpdcli to use the pi as renderer controlling it with Linn Kazoo or any other controlpoint which works with upnp/opnehome. In upmpdcli.conf I've got the following config:

upmpdcli.conf

# Enable UPnP AV services (0/1).
upnpav = 0
# Enable OpenHome services (0/1).
openhome = 1

# Use external command to manage the the sound volume (0/1).
externalvolumecontrol = 1

# Command to run for reading the sound volume.
getexternalvolume = /usr/local/bin/get-volume.sh
# Command to run to set the volume.
onvolumechange = /usr/local/bin/set-volume.sh

# The name of the room where the Product is located.
ohproductroom = Zitkamer

I've created 2 bash scripts: get-volume.sh and set-volume.sh which controls the volume directly using amixer

get-volume.sh

#!/bin/bash
amixer get 'SMSL USB AUDIO ' | grep -o -m 1 '[0-9]*%' | tr -d '%'

set-volume.sh

#!/bin/bash
amixer set 'SMSL USB AUDIO ' $1%

Furthermoe I've added the autosuspend = -1 setting to /boot/cmdline.txt. Whetehr or not that helps...I honestly don't know🙂

root=PARTUUID=e87e153f-02 rootfstype=ext4 rootwait net.ifnames=0 logo.nologo console=tty1 usbcore.autosuspend=-1

Looking forward to any comments on this setup...
thx in advance

willem

 

[Markw4]

With speakers that old, they may need some maintenance. Driver surrounds can crack, and sometimes crossover capacitors can dry out. If such problems are found then fixing them might make a nice improvement to the sound.

Another thing that can be problematic are USB powered dacs. USB power is noisy, and to make matters worse so is RPi, and so in an SMPS wall wart for power. If it were me I would look for a real dac not a USB powered one. Doesn't matter how well a USB powered dac measures on an AP analyzer, since the AP would a much cleaner source than what you have there.

 

[wkloppen]

Hello Mark,..speakers are old but sound pretty neat if my ears don't lie🙂. Dac is indeed a thing. The Mk-II and Mk-III sanskrits are indeed usb powered. I in the building process ofmaking my own short dat only usb cable with silver 0.5mm with 0.4mm ptfe insulation. The dac has an auxilary power input. I tested it with a cut open old usb cable cutting the 5 volt VCC. Unforntunatly the dac won't work like that🙂. I'm looking for the smsl dl200 with "normal" power supply so the data only cable will work (I hope). The Pi itself is powered by an IFI power. After I'm done with this I will have closer look at the passive crossovers in the speakers. I do have the layout and component values already......Winter is coming up...(at least here in Europ....)

reg

willem