@zpl1025 My problem with this is that since then the output signal level of the device seems to have decreased (its output power?!.), the volume levels have at least changed drastically, the position of the volume controls has changed drastically compared to the state in the previous firmware. By the way, even with the previous firmware, I didn’t hear the phenomenon when changing the input, but now it’s disturbing that the output signal level of the device has decreased (I only get the same output signal level at a much higher volume level)…
Hi Zitev, we did not change the total system gain actually. And another change which might affect is about the pre-saved EQ, the old firmware might not take effect. So please help to check the DSP settings if you ever configured. And if no, please try to access the internal WEBUI and see if max volume is changed. And maybe try reset factory.
We’re not meant to cause any trouble, and we did not ever get this issue in the internal testing. I’ll request to do some acoustic testing for this model tomorrow, to check the spec.
@zpl1025 Thanks for the quick reply, the device has never been calibrated with ACPWorkbench, but after firmware has changed the maximum volume in the WEBUI has changed drastically - the first thing that appeared was that after the firmware update, nothing was heard when I started something. After I checked the WEBUI and set the max volume to maximum, I could already hear the sound of the equipment. The maximum volume was set from 30% to 70% (perhaps logarithmic?), and the volume was set to approx. it is in half position, so now approx. the device plays at the same volume as before with a maximum volume of 30% and a volume setting reduced to a minimum. I use three signal sources: internet radio stream, AUX-IN, TOS-LINK
ok, I have no idea why this settings will change when upgraded, but it’s not so bad that the device is working well. 
@zpl1025 Indeed, if only the volume calibration “went wrong”, but if the output power of the device also decreased, then the matter is already problematic - unfortunately, I cannot measure the latter for now.