What’s the reasoning behind using the larger fuse? So it ‘sounds’ better? Because you have a 1.2 and don’t want to buy a 1.0?
Fuses are meant to protect the system in case of a fault where something shorts out downstream of the fuse. If there were no fuse there’d be a massive current draw that could lead to either a burned component or a fire that burns down the house. The wire cord leading to the fuse is designed to withstand the current needed to blow the fuse in case of a short-circuit fault. Ideally the wiring downstream of the fuse will handle this current spike as well. Adding a bigger fuse will put a bigger load on this wiring in the event of a fault.
Most fuses operate anywhere at 30% to 50% of their rating so they don’t blow at power-on during the inrush power transient. So there’s already reserve margin built into the fuse at the nominal rating. Adding more margin by using a bigger fuse won’t change things very much and may be bad in the rare event of a short-circuit fault.
If you have a slightly bigger fuse and if the original fuse blows, you can try the bigger fuse, but chances are that if it blew the first time it may blow again, so find out why it blew and fix that before putting in something bigger.
But if all this is for better sound, just get a fuse like the HiFi Tuning or similar brands that are designed to sound better below their nominal rating and still blow at the proper current to protect you from smoking the unit or burning the house down in case of a fault.