Greetings my colleague from Bulgaria.
I have an amplifier Destiny 2. After his purchase, I opened it to check the IDLE current.
This value is indicated inside the amplifier and is very important for its correct operation.
Transistors that provide a constant current value are pressed against the radiator by plastic clips.
These clips are weakened with time and the transistor loses contact with the radiator.
I highly recommend to replace the clips with special iron, which are used in various electronic modules.
So I did in my amp.

Also of course I replaced a few electrolytic capacitors, problematic in your version of the device