you don't have to replace 300uf but the voltage is important. Watch out for the voltage, it needs to be 250volts and above
i have used 47uf Mundorf Mcaps and it works really well
i had customers who used sprague 100uf and they like it a lot
another brand which another customer said is good is illinois capacitor
again any value would work
but try to use values of uF starting from 10uF and above. too low may cause noise built up