testing power amp

[kambo]

i need to test a HiFi amp 120W / 8ohm,  for 24 hours, see how hot its getting etc, at full volume...
cant play it that loud!
can i just slap a 8ohm/160W wirewound resistor, and let it run for 24 hours!

 

[JohnRoberts]

i need to test a HiFi amp 120W / 8ohm,  for 24 hours, see how hot its getting etc, at full volume...
cant play it that loud!
can i just slap a 8ohm/160W wirewound resistor, and let it run for 24 hours!

Water heater elements can make decent loads, and you can boil water to scrub off some of the energy.

Depending on the amp design, it could get hotter at 1/3 power than full...  but I guess it depends on what you are testing?

Modern amps have not been designed for continuous duty 100% output for several decades now.

JR

 

[kambo]

Water heater elements can make decent loads, and you can boil water to scrub off some of the energy.

Depending on the amp design, it could get hotter at 1/3 power than full...  but I guess it depends on what you are testing?

Modern amps have not been designed for continuous duty 100% output for several decades now.

JR

heater element was first idea,  but readily available resistor very tempting,

cant read the chip on amp, but nothing complicated...
will check at 1/3 too, good to know that, thank you.

 

[JohnRoberts]

heater element was first idea,  but readily available resistor very tempting,

cant read the chip on amp, but nothing complicated...
will check at 1/3 too, good to know that, thank you.

The heat dissipation depends on the amplifier topology... class A/B is worst case for heatsink at 1/3 power. Class D will be roughly linear heatsink dissipation with output power.  Class G/H will be somewhere in between.

Another reason you need an external load is that loudspeakers do not tolerate continuous full power either.

JR