Raspberry pi 4b with dietpi, mpd, upmpdcli, alsa and USB dac

[wkloppen]

Hello there,

I'm looking for improvements on my current setup. I'm using the pi as a streamer for Qobuz. The smsl sanskrit 10-edition MK-III is outputting to my diy wolverine amp which drives 2 Kef reference Model III's from the nineties. To my ears the sound is really good and I'm looking for further improvements regardless whether they are audible or not
I'm in the process of making my own shielded silver wired usb cable between the pi and the dac using only the 2 data wires as the dac has an external power supply input. For power supply of both the raspberry and the dac I'm using a 5 volt 3 amp IFI power supply (ie: I splitted the wires of the IFI power supply which allows me to not use the power wires if the usb connection).
At the moment i'm looking for the best cpu governor and I've understood it's best to have a stable frequency for both arm_freq and core_ freq. Below is my current cpu config. I've choosen the userspace option and configured the frequencies manually.
note: The only thing the pi has to do os passing through the Qobuz music stream. No EQ, no processing whatsoever.

any advise welcome....thx in advance

willem

DietPi CPU Info
 Use dietpi-config to change CPU / performance options
 ─────────────────────────────────────────────────────
 Architecture |     aarch64
 Temperature  |     39 °C / 102 °F : Cool runnings
 Governor     |     userspace

                 Current Freq    Min Freq   Max Freq
 CPU0         |      1200 MHz      1200 MHz    1200 MHz
 CPU1         |      1200 MHz      1200 MHz    1200 MHz
 CPU2         |      1200 MHz      1200 MHz    1200 MHz
 CPU3         |      1200 MHz      1200 MHz    1200 MHz

config.txt

over_voltage=-2
arm_freq=1200
core_freq=500

over_voltage_min=-2
arm_freq_min=1200
core_freq_min=500
sdram_freq_min=600

mpd.conf

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

asound.conf

defaults.pcm.rate_converter samplerate_best

pcm.!default {
    type hw
    card 0
    device 0
    auto_resample false
    auto_format false
    auto_channels false
}

ctl.!default {
    type hw
    card 0
}

 

[Sokel]

My advice would be to scrap the DIY USB cable and get a certified one were the impedance and stuff are taken care off.

 

[wkloppen]

a certified one

Ok,....the usb cable lenght is approx 50 centimeters. Any advice on which cable?...I'm currently using this cable. Forgot the exact specs.....

 

[wkloppen]

Ok,....the usb cable lenght is approx 50 centimeters. Any advice on which cable?...I'm currently using this cable. Forgot the exact specs.....

Ok bad picture. You can almost not see the usb cable

 

[Sokel]

Ok,....the usb cable lenght is approx 50 centimeters. Any advice on which cable?...I'm currently using this cable. Forgot the exact specs.....

View attachment 401979

Just run a google search for certified 50cm ones and the type you want and chose amongst them.
They are around 5 euros or so or more if you want a nice looking one,etc.
Strangely,very short lengths tend to be pricier,don't know why.