A quick question to PS engineers. Is there a reason you do not use electronic resettable fuses (such as breakers)? I am asking as I think it should be a solution that is better than all expensive fancy gold fuses.
good question that I wonder about too.
my amp has breakers and my pre has NO fuse.
Go Figure.
I have an educated guess. Fuses act very quickly , Breakers very slow in comparison. Now there are a type of diode circuit that is auto reset and also very fast. Fuses are cheaper than both other choices.
This is a general statement
Cheap fuses are cheaper 
@mikhail
Is there a link to these things? I have never heard of them.
@mikhail
Is there a link to these things? I have never heard of them.
Sorry, I am not an expert. Just google "resettable fuse". There are many types, not all of them would be good for our application.
I do not think you will find the device I am talking about that easy. Although there are resettable breakers
I did not mean resettable fuses. How ever the diodes are used in a circuit to open very fast and close on a delay or circuit designed to safeguard the drivers. Infinity IRS BETA. Has the diodes as an example to protect the emim drivers . But this same kind of protection is used in many applications , but it must be disigned for the application as I am not aware of any off the shelf items like that . I believe it is a type of Zener diode as this type is used in regulating circuits.
I hope this helps.
I believe resettable breakers are used in PowerPlants (P5 and P10) besides the standard fuses so those should be OK SQ wise if PS Audio use them
But it may depend on brand, model etc… I’m curious if @Paul would comment here
Well, we kind of have to in the Power Plants because it’s part of their function. If too much power we rely on them to kick off and then be resettable by the customer. We’d all be unhappy if the Power Plant fuse blew every time you over drove something. That’d be a pain.
The fuses in a DAC, for example, are for catastrophic failures and screwups. Plugging it into the wrong voltage, for example. Our expectation is that the fuse in your DAC should never, ever blow. The good resettable ones are a lot more money and make sense f that’s likely to happen, little sense if you’re not expecting it to ever be used. Generally, a fuse sounds better than a breaker.
As a general rule fuses and circuit breakers operate quite differently.
Fuses are voltage and/or current ‘sensitive’. Which means either an over voltage and/or high power draw (greater than what the fuse is designed for) will get it to do its thing (open up).
Breakers are usually a magnetic trip device, which means it takes a sufficient power draw (over a sufficient period of time) to get it to trip.
You’ll notice that over voltage isn’t a condition, by itself, to get a breaker to trip. It needs to see sufficient current (power) over time to create ‘enough’ magnetic strength to ‘trip’.
So if protecting from an overvoltage condition is critical, then fuses are better for this.
There are additional factors such as reaction time and for breakers, contact degradation (over the long term) etc.
JJ
Not trying to be argumentive . But fuses are in general not voltage sensitive. If the voltage is what needs to be protective against as in a surge or spike . A diac is usually used . It is a type of diode that has predetermined set point , when reached it opens or shunts depending on the design critirere and protects the down stream device. It is used most commonly to protect a microwave tv or whatever and only works once . Then must be replaced.
If the voltage goes to high the unit will draw too much current thus blowing the fuse.
Basically it’s easier to use a fuse because it’s faster than a breaker, if you use the right fuse, and the safest, cleanest way to make sure whatever happens the unit will be protected.