I have a 1500x here's what I did.
use ryzen master and slowly creep up the frequency. I used cinebench to test each step.
increase freq a bit, run cinebench, record results. when it reboots, and it will reboot. then you creep up the voltage a bit in ryzen master and repeat the process again.
creep the freq, test with cinebench, creep up again and again until reboot and then the voltage and repeat.
took me about 20 tests to find the sweet spot which is where you can push it no more and the voltage is below 1.35 (voltage AMD says is unsafe for daily use).
my settings were 4.0G at 1.35V ( I tested to 1.4V and still no more speed) I could get no more speed despite higher voltage and proper cooling. so I started dropping the voltage until the system was unstable, then that's where I stopped at 1.3375V.
4.0Ghz at 1.3375V which is a 500Mhz overclock across all cores and threads and with a GAMMAX 400 cooler it is cooler than the stock cooler running at stock speed and voltage.