thanks for the link.
and don’t forget a 3amp 5volt power supply…
I’m going to use this, seems sufficient to me.
https://www.audiophonics.fr/en/linear-regulated-psu/power-module-a-19-2x3-20v-lt1083-p-4381.html
1 Like
Hi,
And what transformer?
this one.
https://www.audiophonics.fr/en/toroidal-transformers/toroidal-transformer-60va-2x8v-p-10640.html
it’s a linear power supply Understood,
This approach gives an improvement in sound then a meanwell switching power supply?
Thanks
with a khadas tone board slightly improvement in sound (could also be my imagination) with other i2s dac this gave more an improvement, at least this is what I thought.
and everything is built in a closet and this seemed to me the best solution.
2 Likes
i see only compaibility for pi 2/3 so i can’t say if it’s working on the pi4
https://www.diyaudio.com/forums/pc-based/354885-raspberry-pi-4-khadas-tone-board-streamer-ideas.html
seem to work but there is no case for it … but i think you will creat a case for it 
because you need to put your power supply some where.
but not tested with volumio / pi4 combo yet.
it says here that the touchscreen is raspberry pi 4 compatible.
https://www.waveshare.com/product/displays/lcd-oled/lcd-oled-2/4.3inch-dsi-lcd.htm
the khadas tone 1 goes via usb and the 5 volts to the external input of the khadas. loose data lines from the pi don’t work anyway, I’ve already tried this once.
solution 2.
or this one.
lol i see a lot of bad solderings … but you split data and grond ground and 5+ in 2 cables.
what do you pick it from usb-c or the other way?
1 Like
i saw it already.
if all is well, as soon as you use 5 volts somewhere other than the usb, the power of the usb is automatically cut off.
so as it is said there it is useless.
or would they just mean power from the raspberry pi usb out?
the data lines/ground run to the pi and the other are the power/ground you connect to your supply i guess
the other will run to the tone board as usb-c same as the tone 1 - sep. data /power connections in your post
i have ordered the same card so we will see if it 's ok
so i will have it in a few days to test if it will work i got the vim version
what i have tried is 5 volts directly from a linear power supply to the +/- khadas gpio 5 volt and only the two data lines from the raspberry pi usb to the khadas gpio data in, then the khadas is no longer recognized in volumio.
I have also read more about this that separate data and voltage lines will not work via the gpio of the khadas with a raspberry pi.
very nice, I’m also curious what you think of these khadas.
your missing the ground line ? that’s needed to on the data side you split ground 2 ways…
found one for 45 euro 
recap: power is red / black -------------- data-side is blue / gray / black
the other full plug goes to the tone board.
what you indicate is that you also need the ground cable of the raspberry pi usb output cable, and this ground must then be next to the ground of data “usb dp”?
I haven’t actually tried this yet.
that is what the picture is showing with the wiring in your post …
power is : ( red 5v+ ) / ( ground black ) and dat side is gray, blue and splitted ( black ground ) from power. btw that’s a vim board i guess
