Hi,
Received the tone board it’s excellent! Very happy with this purchase.
My tone board is USB-C powered (and the DAC fed) from a raspberry (if one day, your Vim or edge cards support PiCore player and a rasp 7" touchscreen, I’ll buy it immediately).
Is it possible to power the tone board via a separate power source than the USB from the raspberry?
Thanks
Yes, it works out.
Have fun!
40 Pin Header - pin 1 & pin 21 to wire external 5v power?
Yes,more details see here https://docs.khadas.com/toneboard/UserManual.html
Hello
If the toneboard is powered by the 40-point connector and the audio stream arrives via the USB port C, there is no risk of a voltage rise that destroys the port on the PC side.
A +
Most people would add a external PSU because of noise from USB. I myself would like to build my own lineair PSU for the TB. But when powering the TB via pin 1 and 21 with a external PSU and feeding the dac with data (and ofcourse also power) via the USB-C, the external PSU would be useless because the TB would also reveive 5V from the USB-C which is not as nearly as clean as the External PSU… Is there a way the TB can only get power via the GPIO even if it is also powered by the USB-C? Of would you need a special USB-C to USB cable which would only send data and no power? And will that work or would the TB not be located because it gets no power via USB?
Hello!
Same as Thomas, I’m interested in powering up the tone board by external power supply via pin 1 and 21. And again, same as him I am willing to know do I have to use data only cable for audio signal, since the board will be fed by the external supply.
I have hiss when I maxout my amp, which is absent when the signal is received by coax input. So probably it is noise from the PC USB (strange, I have internal soundcard, which is dead silent).
Hope to find the answer here.
Regards,
Gencho
maybe you should use a purifier like this : https://www.head-fi.org/showcase/ifi-ipurifier-3-0.23374/reviews
or use an expensive linear power supply and inject its 5V in replacement of host’s 5V using one of those :https://www.amazon.com/s?k=ifi+iDefender+3.0&ref=nb_sb_noss
May be it will help, as other similar devises from ifi, audioquest and other brands, but I want to know if there is a way to power with external power supply the board and use direct connection from PC USB without harming khadas tone board.
if you power the board not with the usbC cable, then I think you need to modify your USB-C cable to not provide +5V to the TB
Hello, both power and signal can be connected to the TB GPIO.
Update: I misspoke on the following, it is wrong…
You could have power and signal separate. For USB signal, do not connect it’s power lines. See here. And here.
Sorry, but I can’t understand.
Are you saying that I can have separate signal and power, but without connecting the power lines?
May be you are meaning not to use the 5V through the USB type C connection, from where I’ll feed the board with signal?
Because I think that there will be no data signal from USB C if there is no ground.
My idea is to use the USB C for data and pin 1&21 for power.
I made an error on that. My apologies.
I think that if you power through the USB-C, the signal will be taken from USB-C. And if you power from the PIN header, input will switch to the PIN USB as well.
That is at least how I understand the schema.
It’s easy to connect 5V power to pins 1 and 21. The usb c input still works. This way I can use my phone to play music to the Khadas dac over usb c. Without 5V to the pins my phone and Khadas won’t work together.
You can plug a “Y” split on TB and use a USB type C data (only) cable between your RPi and the TB and a USB type C power cable between your external PSU and the TB.
If you don’t have data cable you can create yours, just cut power wire.
Trying to follow this thread and after reading manual, I’m still confused if powering the board through pins 1/21 allows it to operate from that power while connected to source (such as phone) through USB connection.
It does with my phone. Else it would not make sense to power it seperately.
Agreed. So you still have power on the usb cable coming from your phone?
