Magnepan MG1.7 fuse question


I have placed an order for a pair of 1.7s. I want to upgrade the fuses but I don't know what spec is shown on the back place for the fuse. One person thought the spec was for a 4amp but I thought that seemed high. Could someone please let me know what the amp size it is. I assume it's a fast blow. Any help would be appreciated.
5560
Just added 4 jumpers from Karl at Empirical Design to my 3.7's. Have listened about 10 hours worth. I'm hearing a little more pronounced midrange and a bit smoother highend. Nothing earth shattering but definitely a change. He also mentioned that if I was interested in another tweak that I should look into the Supreme HiFi fuses.
@Jwpstayman If you are driving the amp into clipping, you are an idiot, and certainly not an audiophile!
The back of the panel is a 3AG Fuse 4amp. One recommendation I can suggest to you is the Furutech TF-4A (32mm), would be a great upgrade from that. We sell them if you are interested.