After flashing from v1.2 - Windows 10 device manager not showing it anymore. Ring RGB led is light on. Tryed different cables and PCs. Rolled back to v1.2 and it works flawlessly. Serial № 14A2010D
Strange. That serial number should have shipped with the latest MCU firmware. Hopefully folks here can help.
It is strange for me too. I placed an order on Nov 12 and expected the latest firmware. Unfortunately no preamp with v1.2 
Hi @devadaru_revolution, sorry to hear about the old firmware - where did you purchase your Tone2 Pro from?
After updating the XMOS, did you try long-pressing the volume knob to shutdown, and then short-pressing to reboot the Tone2 Pro?
Hello, I bought it at aliexpress Khadas Store (order 3014173851782622 ). Right after flashing to v1.3 the Tone2 works fine until I shut off the PC or disconnect the usb c cable. After that - neither helps to bring it alive - pressing the volume knob to shutdown/reboot or pressing volume knob while starting the PC. I could get it work randomly after 5-6 attempts to connect both Tone 2’s usb c ports to PC. So, I can say - after v1.3 the board is in unstable condition. Few times I’ve been able to flash it with v1.3 and get back to v1.2 with the same result - non-working v1.3 and v1.2 that behave perfectly.
Understood, could you tell me the serial number of your Tone2 Pro? Thanks.
Tone2 Pro Serial № 14A2010D
Hmm this should update to v1.3 without any issues, since it is a newer model than the 11xxx batch seen here: https://www.khadas.com/post/tone2-pro-firmware-v1-2-for-xmos-mcu
Maybe @Eric68 has some ideas about what is wrong.
Thanks for helping, and , yes, I’ll definitely need eric68 help since I miss preamp feature and can’t use Tone2 Pro with my system (amplifier doesn’t have a volume control)
The only way to force it working with v1.3 was to cut VCC contact on usb-c cable and to use LPS on the I2S port. The sound quality increased dramatically versus pc onboard port (I use Sigma11 single rail discrete LPS)