Download the firmware from HiBy website and put the file r3pro.upt on the root of microSD card. Make sure that R3Pro is powered off, if not, press and hold power button more than 10 seconds. Insert microSD with placed firmware file and then press and hold two buttons together: Power button and...

I'm not good in that. I stopped on Intel AX210 WiFi/BT card, and its BT is compatible with the alternative A2DP Driver. There is also RTL8761B based devices but it have to check the specific device to work with alternative A2DP Driver.

It's obviously branded OEM device, one of KB8 or KB8P (in case 24bit 96kHz) device http://www.hstech.com.cn/index.php?c=content&a=list&catid=37 You can find those devices on Aliexpress like Vaorlo KB8/KB8P https://aliexpress.com/item/1005004898804478.html or another branded but same device.

No, KB9P is recognized Windows as USB Audio /soundcard, not as Bluetooth device.

TempoTec V6 disassembly / internal photo / teardown originally posted on https://4pda.to/forum/index.php?showtopic=1082004&view=findpost&p=130060113 Last three attached images are contain the battery photograph.

I've finally got E-mail with latest firmware 2.14 for KB9P from Vaorlo AliExpress seller. I've just updated my KB9P from 2.11 to 2.14 fw. https://www.mediafire.com/folder/luenoflszpga2/KB9P+Firmware+2.14 All software and firmwares https://www.mediafire.com/folder/wm0nsvo31p4jq/KB8_KB8P_KB9_KB9P

The KZ 784 cable with SE 3.5 can easily be modded to balanced 4.4 with this jack https://aliexpress.com/item/1005003630325689.html (AF4.4TQ-W TRRRS / AF4.4TQ-B TRRRS). You actually may left the stock fittings, and only replace the jack - the soft coupling and furniture tube may remains original...

Some internals, disassembly and measurements http://www.soomal.com/doc/10100006213.htm http://www.soomal.com/doc/10100006264.02.htm additional http://www.soomal.com/doc/10100006422.htm AM2 disassembly http://www.soomal.com/doc/10100006491.htm http://www.soomal.com/doc/10100006465.htm AM3...

Try to contact directly to http://www.hstech.com.cn/ They stopped to publish new firmwares, the latest published fw on the website is 2.11.

As I know that limit is related to sqlite3 library performance on Ingenic X1000E in HiBy OS. In latest HiBy OS (Tempotec V3 fw v1.0) that limit is 50000. The previous way to fix that limit was manual patching the binary (another one) and obviously limited by max value of 16 bit unsigned integer...

There are some alternatives https://www.aliexpress.com/item/1005005576466198.html https://www.aliexpress.com/item/1005005576473109.html https://www.aliexpress.com/item/1005005320008654.html https://www.aliexpress.com/item/1005002397810175.html...

N6 Firmware archive https://disk.yandex.ru/d/PGl8AmI_7HuuQg

Did you try to enable/disable "USB DAC feedback" in System menu? https://www.head-fi.org/threads/the-new-hiby-r3-ii-is-here-4-4mm-jack-improved-sound-and-bluetooth.872288/post-17985829

Blue capacitor block marked '47 10a' (47uF 10V) is for VREF decoupling. Red capacitor block marked 'JJ8L' (220uF 6.3V) is for LPF (OPA1652) decoupling.

I saw the messages in chats form experienced users who disassembled March III, V3 and V6, and they wrote the devices internally are similar. But they do not share internal photographs and do not answer to request those photos. I don't have V6 or March III and didn't find any disassembly/teardown...