Paulwp, welcome to the world of marketing by specs.

Remember, power = current squared times resistance. Using 40 amps and 25 watts, this says that:

25 = (40)^2 * r where r = resistance. solving for r we get a value of about .015 ohms.

In other words, if those numbers are correct, the amp only delivers 40 amps into essentially a dead short. What is the minimum impedance the amp is rated to drive?

At 8 ohms the amp could deliver about 1.8 amps, and at 4 ohms about 2.5 amps. This assumes the amp delivers 25 watts at both impedances, which is probably not true.

In short, these numbers don't really make sense.

I also like the weight test mentioned in previous posts.

As always, trust your ears.

Remember, power = current squared times resistance. Using 40 amps and 25 watts, this says that:

25 = (40)^2 * r where r = resistance. solving for r we get a value of about .015 ohms.

In other words, if those numbers are correct, the amp only delivers 40 amps into essentially a dead short. What is the minimum impedance the amp is rated to drive?

At 8 ohms the amp could deliver about 1.8 amps, and at 4 ohms about 2.5 amps. This assumes the amp delivers 25 watts at both impedances, which is probably not true.

In short, these numbers don't really make sense.

I also like the weight test mentioned in previous posts.

As always, trust your ears.