OceanOfLight
Head-Fier
Sorry if I intrude, but I got the same problem.
I think you misunderstood the issue.
The real problem is that to actually make the device enter Low Gain mode, after every reboots you have to go under the Gain menu, and now there are two possibilities:
1. if you were using High Gain mode, you only need to switch to Low Gain mode.
2. if you were already using Low Gain Mode in order to make the device effectively go in Low Gain, you need to switch from Low Gain to High Gain to Low Gain again (as I show in the attached video).
So, to be clear from the start, the real problem is that, if you shut off the device while in Low Gain, on reboot the device will operate automatically in High Gain without actually telling you that. (It will in fact show the "L" on the display and Low Gain in the submenu, but as I said, it will effectively operate in High Gain).
So, this is not a problem for people who use High Gain only, but it is a really big one for people who use Low Gain instead, cause with low impedance IEMs after every reboot (when I forgot to fix the problem with the abovementioned procedure) the volume will be so loud that it could potentially damages the IEMs (and me).
So, to reproduce the issue (for your engineers) let's go by steps:
- The BTR15 is turned off and not connected with USB to the pc.
- Attach an IEM and turn on the BTR15.
- Connect the BTR15 to pc via usb C.
- Go under the GAIN submenu and:
1. if you were using High Gain mode, switch to Low Gain mode.
2. If you were using Low Gain mode, switch from Low Gain to High Gain to Low Gain again.
(you can check that the change is effectively happening because you will hear a popping sound in the IEM when switching from one mode to another, if you are not hearing it, it's not really switching).
- Now the device is finally set to Low Gain.
- Listen to a song with at a volume you think is right.
- Reboot the device and wait for 5 seconds.
- Now the device will operate in High Gain again (despite showing the L on the screen), you can confirm this by listening the same song (at the same volume). Now the song will be way louder.
This clearly indicates that the device reset itself to High Gain (on its own) after every reboot. To have another confirmation of this, go now to the GAIN submenu and switch from Low Gain to High Gain. Now listen to the same song again. There will be no audible change in volume (it will still be as loud as before), because the device was already functioning in High Gain mode before you actually switched to it.
The heart of the matter is that the BTR15 will set itself on High Gain mode after every reboot. The only way to set the device to Low Gain is:
1. if you are using High Gain mode, switch to Low Gain mode.
2. If you are using Low Gain mode, switch from Low Gain to High Gain to Low Gain again.
This is the only way to set the device effectively to Low Gain, but as for now, this procedure needs to be repeated every time the BTR15 is rebooted.
I really think this problem affect every single BTR15 unit, but only the people that use the device in Low Gain mode are able to realize that.
Now, if you can't replicate the issue and fix it, I give up.
And I'm now realizing I ended up writing a manual on this simple issue. You should consider gifting me a KA17 for the efforts.
I decided to repost my report, because I suspect Fiio didn't see it (too many posts on the thread, maybe).
Can you please address the abovementioned issue on the BTR15 with your engineers?
If you already seen it and reported it to them, do you have any news about it? Thank you for your time!
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