'm transfering the code below to an UNO(SMD) and the frequency is around 15kHz...
The same code transfered to the MINI and the frequency is around 15Hz??? :o
Are you sure of this? Are you using the Arduino IDE?
When you use |= to set up TCCR1A and TCCR1B you are not clearing the presets used by the IDE to set up Timer1.
On the Uno, you will be in mode 7 (bits set in WGM12:WGM11:WGM10) which is fast PWM to 1023, but the prescaler will be 64 because both CS11 and CS10 are set by the IDE, and you are not clearing CS11. Frequency should be about 235Hz.
Initialize the registers with TCCR1A =0 and TCCR1B = 0 before you set them up. If you do that, you should be set up for 15Khz.
I don't think there are different Timer1 presets on the mini and the uno, so I can't address the difference you are seeing.