current versus watts

I would think it would be on a spec sheet for that particular fuse; I would start with the manufacturers website and look at a spec sheet if there is one.

Magfan -- I second Rleff's suggestion. For instance, the Littlefuse.com site provides datasheets indicating opening time vs. current overload percentage, and also a nominal melting figure in units of ((amps squared) x (time)). I assume other manufacturers have similar information as well.

Best regards,
-- Al

Dangelod:
with the best amps doubling output as impedance is is halved.

you're talking audio, man! what's 'best' for you could be 'trash' for another listener! There's no objective definition of 'best amp' in this hobby - it's all VERY subjective.
So, I'd say that many of the large chassis (think Rowland Model 8, 9, the MBL 1200W/ch used to drive their radial speaker, Gryphon & others in that chassis size) & expensive amps (think top-of-the-line Krells from the late 1980s, present MBLs, Boulder, Rowland Model 8, 9, Gryphon) show this tendency. Most amps in the market do not have this proprty - it's very expensive to make them have this property!!

Dangelod
Seems like all high quality amps clearly describe output in watts........
But, I do not see(often) specs on current ?

That's because Power = Volts * Current = Current squared * Impedance (or Resistance). So, if you know Watts & Resistance you can calcuate the output current. Herman has already done those calculations for you in an earlier post. Those calculations pertain to maximum output DC current of your hypothetical 300W/ch into 8 Ohms i.e. output current when the amp is outputting 300W. You should realize that such an event is unlikely to occur frequently unless you are listening to music at paint peeling high levels (& ruining your ears!).

Dangelod:
Is high current as important to quality dynamic sound as high watts.....
If so, what are the general ranges of current output that would be acceptable for a high quality amp.

yes & no - depends on the speaker you are using. Some speakers are notorious for needing a large reserve of current to drive them to their best performance & other speakers are an easier load on the amp. Hence, there is no clear definition on what is considered a general range of output current. As another member pointed out - depends on the speaker impedance-phase curve.
But, as Atmasphere wrote before, whether you output small amounts of current or large, you need to do so with minimal distortion otherwise the sonics are strident. At high distortion levels it won't matter whether you have the "best" amp or not, the music experience will come up way short.

The conclusion is that the amplifier-speaker interface is a complex one because the speaker load affects the amplifier output impedance & vice-versa. Plus, the speaker impedance & phase varies over frequency. So, as you run up/down the audio spectrum, nothing remains constant! So, you will not be able to take a fixed number (amplifier output current as you are asking) & apply it to an interface that has variable performance....
IMHO. FWIW.

When we are talking 'best', IMO power doubling has nothing to do with it; none of the 'best' amps I have heard have that capability.

I feel that the specs have no meaning if the resulting amp is unlistenable. IOW our ears are more important than the amp is- our ears are the most important aspect of audio. Its important to drop all the preconceived notions about specs, including the ability to double power, if you your goal is for the system to sound like real music. see

http://www.atma-sphere.com/papers/paradigm_paper2.html

for more information

".... output current when the amp is outputting 300W. You should realize that such an event is unlikely to occur frequently..."

Well, measured (MEASURED!!!!) peak power needed to drive B&W 805 bookshelf speakers at musical peaks waw 3500 watts i.e. not three hundred but more then three thousand watts and for 87.5 dB sensitivity bookshelf speakers.

Only Simon Thacher from Spectron (to the best of my knowledge) is trying to "connect" specs of their amp with its musicality and many, me including, compare their amps to the best tube amplifiers.

The problem is not in specs. The problem to read them and understand them. The problem that many of not most amp producers show misleading specs like we discussed above peak current for 20 msec or displaying distrotions at low (typical number is 10 watts) output and not full output and at 1kHz only etc etc.

So, yes - you are better off listening to the component but it does not hurt to understand too...

John and Simon's philosophy is iltra low distortions and then you hear real (well recorded...) music without ear piercing or euphinic colorations.

Rafael