Volumio + Khadas TB poor sound quality and background noise

Hi to All.

I installed the latest version of Volumio on RB 3 B + connected to a Khadas Dac Tone Board via USB port.

When I start Volumio without playing anything, I hear a background noise on my speakers.
Moreover if I play a song from flac file the sound quality is poor compared to this configuration:
pc with Windows 7 connected to the same Dac Khadas TB via Usb and Foobar palyer.
In this configuration I do not detect any background noise on the speakers.

To avoid electrical problems, I use the ALLO AC/DC Switching Power Adapter 5V 3A DC.

Has anyone any experience to solve those problems ?
Thanks.

Strange my Khadas is dead silent and sound amazing.
Maybe try to run First Config Wizard again?

Thank you Solveit.
I remeber that in the first config I haven’t connected the Khadas Tone board to RB and then I have changed the configuration to use the Khadas.
I’ll try to run First Config Wizard again this evening.

But now the sound quality is very poor compared to a pc with Foobar.
Perhaps it would be better to buy a Digi + card to bypass the Usb port of RB ?

I hear no difference with PC and RPI via USB.

Hi happymax

volumio 2.668, RPI3B+ and Khadas generic TB and allo 5V3A sounds great here.
(using Tone board FW 1.04 dl.khadas.com/Firmware/ToneBoard/ )

Last night I restored Volumio to the factory values, re-run the configuration wizard with KTB connected but nothing has changed.
I also checked the KTB firmware version and it is 1.04
The background noise after turning on RB (without play anything) is always present and the sound quality bad.

I also wanted to clarify that I am using a 128 mb SanDisk SDXC UHS-I SD and in the Volumio Internal folder I copied only one test flac.

Surely it is not a KTB problem because with the pc and Foobar it sounds great.

Could it be a problem with the Raspberry card or the power supply (but the power LED is fixed and does not indicate voltage problems)?

Please give me some advice on how to proceed to investigate those problem.

Thanks.

my recommendation is to check out one by one.
are cables ok? is tb right connected (red and white rca)
try another psu or powerbank
try a 16GB Samsung, Sandisk or other SDcard
swap RPI

Hi Judydudi,
from KTB to Amp it’s all correct; when I listen the same flac on PC with Foobar I don’t change anything after the KTB and everything works fine.

Do you know if I can use a cell phone powerbank or a plug to charge the cell phone to power the RB?

Thanks

just try. More ampere is better then less :slight_smile:
keep in mind, that KTB is taking power too.
my powerbank does have a 2.1 ampere and a 1 ampere output.
It works with the 2.1 ampere, but i took for be save a parallel connection of both outputs…
pwbank.jpg

I run both Khadas and RPI 3B with standard adapter 2.5A with no problem.
Khadas have very good power filtering.

The problem is the ALLO AC / DC switching power adapter.

I used a simple cell phone battery recharge and the background noise disappears.

But the sound quality is always better with windows 7 and Foobar.

now you might hear the RPI ‘USB bottleneck’ and the poor cell phone PSU.
now you can change to RPI4, which should have a cleaner USB port.
Also you can try a USB purifier/Reclocker
volumio.org/product/ifi-ipurifi … reclocker/
ideonaudio.com/product/3r-usb-renaissance-mk2/
and a better psu would be
volumio.org/product/ifi-ipower/

HI judydud,
compared to RPI 3 B + is the sound of RPI 4 better?

What do you think of a linear power supply (around 50 €)?

The other components you propose are very expensive, so I would avoid buying them.
Now with Foobar and Windows I get a much higher sound quality at no cost and I’m thinking of interrupting my project with RPI and Volumio

i don’t know if you would hear any improvent with these items.
people said the USB controller is more clean on PC (X86/X64) and now also on RPI4.
For I2S DAC boards, the most audiophile choice might be a RPI before RPI4…
Same with power supplies. some solutions need a better psu, some not.
It is a journey, i would say. Good luck from here!

Hi Judydudi,

I totally agree.

I tested driving the Aroio DAC with two pieces of LT3042 based power supplies driven by 2 heavy high quality torroid transformers from my test bench - and - at least me cannot really state having heard a real difference. Really interested if the audience at your next listening test will do. Maybe i missed the golden ear :wink:

The same power supply made a clearly positive difference when supplying the Terraberry 2 DAC from external ( you know - the “velvet” sound from the AK chip).

I think the onboard power supply of the Aroio DAC is simply designed significant better …

LT3042 boards:
https://www.ebay.de/itm/Low-Noise-LT3042-Linear-Regulator-Power-Supply-Board-DC-Converter-Overvoltage-Ne/263468156656?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649
Take care: The boards came with “Nover” capacitors (6800uF/35V) instead of the Nichicon (6800uF/25V) shown on the pictures.
I got 4 british pounds back for each board - but make sure you are equipped with suitable capacitors to replace. (i prefer the Nichicon - 8€/each)

Some day i will get me a weekend to visit your much appreciated sound check session in Hamburg.

Best Regards
Josef

Hi Josef,
glad to have found in you a buyer who appreciated my Terraberry and knows to ‘ride it’. :smiley:

What about coming together for a soundcheck in Firenze, Italy?
For you it’s even closer :wink:
Best regards, jens

PS: pls. excuse this OT talk

Hi Judydudi,

Addendum:

I’m designing my power supplies generally this way:

High quality torroid (at least “Talema” - have some really good shielded transformers only at my test bench…)
Rectified by quality schottky diodes (no bypass caps) followed by current depandant CRC filters (prefered as much as possible ~Nichicon 1800uF max for the first C stage - 2 Ohms resistor (just testing with low impedance L, too) - followed by high quality electrolytic capacitors (Nichicon GOLD).
This goes to the regulators (LT1963 or LT1083/LT1084 for the PI and LT3042 or LT3045 (ideally more of them in parallel for the digital and 1 more for the analog part).

However, it also seems to me that all this effort is less important on some DACs (e.g. Aroio).

@Hanno Sonder:
I am dreaming of an ES9038Q2M based (ideally 1 for each channel) “Aroio 9038” what do you think ?

Best Regards
Josef

Hi Judydudi,

sounds very good - only i’ve a lack of time. When do you think we could meet in Firence ?
(For me it is not much more far then Hamburg…:slight_smile:
Will Michelangelo be on board ?
Have to check back with my beloved girlfriend…

Anyway - yes - we should meet.

Best Regards
Josef

I asked Hanno last week via telephone about plannning a new DAC board. currently he is not.

That’s kind of sorry - but did you listen to the Audiophonics ES9038 board - or even the (unsupported) AOIDE DAC II - ES9018 based board ?
I “frickeled” around a long time to get this working with Volumio getting a little help of my Linux Guru friend (Simon Reiser).

The power design of both boards is a bit of poor, i think. But the sound is even impressive - if the drivers are implemented the right way.

I just wished Hanno would do the design of an ES90x8 board…

…josh