Wut Makes Stable Unstable?

[IH8PunkRok]

so some amps are 2 ohm stable and become unstable at 1 ohm (or .5 or whatever)

wut exactly is becoming unstable?

im just kinda curious and cant quite figure out wut is failing because of low resistance

[raytard]

too low of a resistance, too much current flows through, too much heat is created, amp overheats and fails

most have a way of sensing too low an impedance and tripping protect before they overheat

others just wait until they overheat (like a higher end MA audio amp, like the hk4000 ..most times it will run fine at a low impedance until it gets hot and then shut off)

[IH8PunkRok]

so when they overheat is there physical disconnections which kills the electricity flow? basically its just melting shit?

[Audioguy564]

When designing an amplifier one of the questions is at what impedance will it be stable. when the amp is stable at low impedance the rails are typically lower so the power supply is built for that application. The power supply is usually what makes the amp stable as it has to be over built to handle the current draw and increase dissipation of those low impedance.

[raytard]

there is a little sensor on the board that determines the temperature and causes the amp to shut down, you'r computer has one as well hooked up to the cpu and probably some other parts if its a newer computer

some reaaaallly old school amps had a fuse type one that would melt and kill the connection, most new ones have a thermometer of sorts that detects temperature and cuts the amp out at a certain temp.

its basically to keep the amp from frying board traces or fets from overheating, its much better to shut off and save itself.