Well, to begin with, the specs are stating the VA ratings, not Watts. In typical case the VA number will be higher. You can easily google the difference between the two. I just stuck the power meter on one REX power module and got 155W and 180VA.
In addition, the specs have to be conservative, worst case. There will always be variations due to a particular tube set parameters (there are tolerances to everything including the heater power) and line voltage value - it is supposed to be 120V, but can be higher.
Normally the 2A fuse has sufficient margin, but in rare case can blow for no good reason, simply due to variations in turn-on conditions. If that happens replacing it with a 2.5A or even 3A fuse might make sense. As I mentioned, cases of a 2A fuse going for no good reason have been extremely rare.
Regards,
Victor Khomenko
In addition, the specs have to be conservative, worst case. There will always be variations due to a particular tube set parameters (there are tolerances to everything including the heater power) and line voltage value - it is supposed to be 120V, but can be higher.
Normally the 2A fuse has sufficient margin, but in rare case can blow for no good reason, simply due to variations in turn-on conditions. If that happens replacing it with a 2.5A or even 3A fuse might make sense. As I mentioned, cases of a 2A fuse going for no good reason have been extremely rare.
Regards,
Victor Khomenko