AudioNervosa

Specialists => Audiologists => Topic started by: rollo on February 13, 2023, 01:16:50 PM

Title: Fuse for Power Inlet
Post by: rollo on February 13, 2023, 01:16:50 PM
  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
Title: Re: Fuse for Power Inlet
Post by: _Scotty_ on February 13, 2023, 10:34:45 PM
Theoretically, if there were a big enough short to ground and or a fire then the fuse would blow.
Have you tried successively bigger fuses than the stock value until you could no longer hear a difference
between a fuse and the copper bypass wire. It might be possible to substitute a large fuse for the
copper "rod" and still maintain some measure of protection in the even of a
high current dead short or a fire.
Scotty
Title: Re: Fuse for Power Inlet
Post by: rollo on February 14, 2023, 09:06:32 AM
  In my DAC yes. A 5A instead of 1A. Sounds better to me than 1A fuse. Next up slug it all.

charles
Title: Re: Fuse for Power Inlet
Post by: P.I. on February 21, 2023, 04:58:24 PM
I came across this today.  A safe way to replace that pesky fuse.

Swiss Digital Fuse Box

https://verafiaudiollc.com/
Title: Re: Fuse for Power Inlet
Post by: GDHAL on February 22, 2023, 06:12:34 AM
Quote from: rollo on February 14, 2023, 09:06:32 AM
  In my DAC yes. A 5A instead of 1A. Sounds better to me than 1A fuse. Next up slug it all.

charles

Inserting a fuse of greater amperage capacity than specified by the manufacturer exposes the gear that the fuse has been inserted into to damage outside of any warranty, and indirectly creates a fire hazard. May sound better (likely placebo effect though) but unwise nevertheless. :nono:

Best.

Hal
Title: Re: Fuse for Power Inlet
Post by: P.I. on February 22, 2023, 11:08:01 AM
Quote from: GDHAL on February 22, 2023, 06:12:34 AM
Quote from: rollo on February 14, 2023, 09:06:32 AM
  In my DAC yes. A 5A instead of 1A. Sounds better to me than 1A fuse. Next up slug it all.

charles

Inserting a fuse of greater amperage capacity than specified by the manufacturer exposes the gear that the fuse has been inserted into to damage outside of any warranty, and indirectly creates a fire hazard. May sound better (likely placebo effect though) but unwise nevertheless. :nono:

Best.

Hal
Indeed.
Title: Re: Fuse for Power Inlet
Post by: steve on February 23, 2023, 04:45:52 PM
Quote from: rollo on February 13, 2023, 01:16:50 PMWhy 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, 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.