Hi,
I recently discovered the Chinese VHF-UHF RX/TX Quansheng UV-K5(

radio and decided to buy one for less than 20 euros!!
It is indeed a fantastic piece of hardware for this price.
However I found the sound too high and I decided to make a first modification.
We can already find examples of modifications on the web, however they are not really documented with measurements taken before and after the modification.
Inserting a 330pF cap between pins 4 & 5 on the audio ic LN4898 allows an attenuation of -3 dB at 2200Hz and up to -10dB at 10kHz.
This cheap chinese jewel sounds really better now !
I invite you to discover the modification and the measures that I carried out, your comments will be welcome.

Regards
Eric