I have a toilet that when it fills up, the water line makes a really loud sound until the toilet is full. I replaced the waterline from the shutoff valve to the tiolet and the unit inside and it still does not help. The noise is driving me crazy during fill up. HELP!

Can it be the shutoff valve? It seems like the sound is coming from there. We never had pressure issue. We recently shutoff the valve and did some tile work and the problem came when we replaced the toilet and turn it back on. I don't have a welding experience to put on a new valve. Can the valve be replaced by merely fixing the internal mechanism?