Why do we need this fuse at the IEC ? Had a 211 tube blow, caps blow up. That fuse never failed. Is it for surges ?
Anyway with these expensive fuses out there which sound different why not just put in a copper rod instead. Then no throttle effect, meaning going from 10ga wire to a tiny fusible link.
Well I did and the results were impressive. Dynamics increased, quieter, more info overall. A UL requirement maybe that we do or do not need. ????
charles
Hi Charles,
I would like to add, besides improper fuse value (too large or slo blo),
that it is possible, under unique conditions, that a tube, capacitor, resistor, wire could arc,
but not enough current flow to blow the correct size fuse. It is a high resistance condition
that should not exist. It draws more current, but not enough to blow the fuse.
Another situation, the fuse has to handle the initial conditions (power switched on),
could draw many times the normal operating current, thus necessitating a slow blow,
and/or larger size fuse. Capacitor input filter designs are especially prone for this condition.
Fortunately, the internal parts are generally encased and protected by its sealed
metal chassis. Still, not the best situation, but common.
As another example type, decades ago I had an expensive tube amplifier brought in for repair;
it smelled of smoke. Turned out the manufacturer had designed a 250 v rated fuse into a 500 volt DC line.
In this case, when the fuse blew, the fuse continued to internally arc, being overrated by 250 volts, and
thus melted the fuse holder that was soldered on the pc board. Fortunately, that was the extent of the
damage. Could have been worse. A similar scenario can happen with solid state.
cheers
steve
ps. Upon review, I cleaned up my post a little.