=A0 =A0 +-------+
=A0 =A0 | =A0 =A0 =A0 |
=A0 =A0 | =A0 =A0 =A0 |
=A0 =A0 | =A0 =A0 =A0 |
=A0 =A0 | =A0 =A0 =A0 |
=A0 =A0 +-------+
=A0 =A0 +-------+
=A0 =A0| =A0 =A0 =A0 |
=A0 =A0 | =A0 =A0 =A0 |
=A0 =A0 | =A0 =A0 =A0 |
=A0 =A0 | =A0 =A0 =A0 |
=A0 =A0 | =A0 =A0 =A0 |
=A0 =A0 =A0+-------+
If you've got a 'scope you can also just hit the RC or RL with a square wave and find the time constant. (The point where the voltage falls (or rises) by 1/e).
To the OP, If you want to do more than run stero speakers you can also buy power opamps. I like the OPA544 (I think that's the number.) ( It can do at least 2 amps... more if you don't ask it to dissipate too much power. Hmm, Just checking digikey and they are more expensive than I remember ($18 for one) and also out of stock.
George H.