my stereo cuts off at high volume

i have an visionik amp that has a built in fan it is popping both of the fuses after it runs for a minute it doesn't pop them as i put them in. i have looked at most of the wiring going to the amp. it recommends two 20 amp fuses should i put like two 30amp fuses and see what happens

i have a 600 watt visionik amp yesterday i was driving to my grandmas and i noticed that my sub stoped hitting so i stoped to see what was the problem it blew both fuses so i put teo 20 amp fuses back in it and it lasted for a minute or so and stoped so i just checked it and tryed more fuses same thing happens i have checked my sub wires they are fine. what is causing this

What size fuse is on the amp itself? It might be that 20A fuse may be too small.

it has teo 20amp fuses