[ATimoff]

@Vitaliy Belz I've been thinking about it for a long time myself. Especially if you put it on its side. In a good way, you need to measure the temperature of individual nodes and see their technical characteristics. I wouldn't be surprised if everything is within operating temperatures. It's just now such an element base, large currents. Warm air has become the norm.

 

[hjf3Gd]

Hmmm.......would be interested to know what you all think of this - I've always run my HEDDphones on high gain, but just now I thought I'd try them on medium. Obviously, I've had to turn the volume up more, but the dynamics seem to be improved, somehow the balance of the sound between low, mid and high frequencies seems better and I'm pretty sure that the sound stage and separation is improved. Let me know what you think - but maybe you'll need power-hungry headphones to hear the difference.......?

 

[ATimoff]

@looki look I myself do not like low-quality resampling with bad fast algorithms. Android is Linux. On Linux, resampling is handled by the sound server, depending on its settings or restrictions imposed on it by the receiver. We believe that the music player does not change anything. The receiver is a BT transmitter module. Conclusion: You need to delve into the settings of the Android sound server and the BT transmitter. But is it worth the bother? I doubt that you will hear the difference between 44.1 and 48 in BT mode.

 

[ATimoff]

A good idea comes later, with a sip of strong coffee. For fine-tuning the "sound server" and BT. Find third-party programs for this on Google Play.

 

[Moon5123]

The way to reproduce the issue is as below.
1. Move the first switch all the way down apply bit more pressure to move the switch down.
2. Move the gain to high gain as it only reproduce in high gain. When switching to other gain its working fine.
3. Play some music, wait for few sec 10 or 20 sec the audio output switches from HP to DAC mode (the volume slider was not changing the volume on my xb30 speaker.

Attached a video link where the sound was first played in sundara and then in fee sec it auto changes to DAC mode with some internal clicks in K9 pro.
https://drive.google.com/file/d/1Ok47VIivoarY99wN5PyZH10OZZpU11RT/view?usp=drivesdk

If any one else is facing the same issue then they can use below drivers for K9 pro:
https://drive.google.com/drive/folders/1SbHauynXIqGQH93BL5pJMi5b0cXlZT8_?usp=sharing
This driver change the timing of the mode change by 1 sec or 2 which lets K9 Pro smoothly transition to other mode and doest bounce back to other mode on high gain.
This delay is bearable and definitely resolved my issue.
I was really amazed the fast response and fix I got from fiio support. Thanks.

 

[WorksUnit]

Hmmm.......would be interested to know what you all think of this - I've always run my HEDDphones on high gain, but just now I thought I'd try them on medium. Obviously, I've had to turn the volume up more, but the dynamics seem to be improved, somehow the balance of the sound between low, mid and high frequencies seems better and I'm pretty sure that the sound stage and separation is improved. Let me know what you think - but maybe you'll need power-hungry headphones to hear the difference.......?

If you get a benefit, then great.
(A couple of my headphones respond to that approach quite well too, not just a K9pro thing IMHO).

 

[FiiO Willson]

If any one else is facing the same issue then they can use below drivers for K9 pro:
https://drive.google.com/drive/folders/1SbHauynXIqGQH93BL5pJMi5b0cXlZT8_?usp=sharing
This driver change the timing of the mode change by 1 sec or 2 which lets K9 Pro smoothly transition to other mode and doest bounce back to other mode on high gain.
This delay is bearable and definitely resolved my issue.
I was really amazed the fast response and fix I got from fiio support. Thanks.

Yes, there is a 2 second delay when switching the gain button.

 

[FiiO]

Will this plastic shield lead to rapid degradation of electronic components?

Dear friend,
1. This plastic shield could keep the structure more stable. The K9Pro would not be damaged by the plastic shield under normal usage.
2. Though the radiating will be affected slightly, the K9Pro has temperature detecting and protection which could keep the K9Pro work in safe range. So please don't worry.

Best regards

 

[dpump]

I'm confused about the plastic shield. Is the plastic shield already installed in the K9 Pro from the factory?

 

[ATimoff]

The main task of the screen is to "keep the structure more stable"! I realized that this gives additional rigidity to the circuit board. I didn't understand anything from the rest of the explanation. If this is interesting, then measurements of the temperature of the nodes are needed... after 1 hour.. If someone is still not sure about this plastic screen.... It doesn't bother me. I'm interested in something else. Are the internal generators in the BT module de-energized or not? When manually switching the sound source, for example to USB or COAX. Are there knowledgeable?

 

[ATimoff]

I read somewhere on the Internet .. .. that a decrease in temperature by 10 ... 15 ° C can double the life of a semiconductor device. Look at the listed device life and make a decision. Need to worry further or not.

 

[looki look]

you can adjust volume with app through BT in all modes (tried with coax) so BT module can not be de-energized without loosing App-control.

has anyone win11 and tried BT to k9pro? I just installed a new Win11 with a intel ax210 bt 5 card. But I can't see fiio k9pro. Is this not possible with Win11/only possible with Android?
I see with win11 much less devices than with android, so I suspect the win11 bt driver...

 

[ATimoff]

@looki look Thanks! Helpful information. With an infrared remote control, life would be easier. Well, or with an additional option to turn off the power of the BT module in the control program for the "USB, COAX, OPT, LINE" mode. And more about Android. The resampling rate can be changed by another program running at the same time as the software player. The sound server has given this program priority. It could even be an antivirus.

 

[llysender]

Just got the stand. The recomended mounting position means you need a L joint usb otg in order to properly attach as the port is facing down. Just why?

 

[looki look]

isn't it possible to just rotate the hp-out part downward, then the usb otg is on top.