Oops,
correction in the second to last paragraph,
"Since the power supply can provide more current the amp’s actual power drops as speaker impedance goes down. This is just the opposite of those big He-Man amps."
It should read "... supply CAN'T provide more..." That should make more sense.
Jwrobinson - you are correct about how things are rated. I had a low buck Sony receiver rated at 60wpc into 2khz. No mention of 20-20khz rating. We have the same view on power supplies. Big supply means you have more power as the impedance drops. If the PS is just big enough for an 8 ohm load (ie it's current and voltage limited at 8 ohms), it will stay current limited into a lower impedance load. Do a little math and the amp is becoming less powerful as the impedance drops.
Of course this is a simplistic take on the subject and looks solely at output power, which we all know is not the best way to judge amps. I came up with this to answer my friend's question, "Is a 75w Rotel as powerful as my 100w Sony." This is a somewhat technical answer but my friend is an electrical engineer and who understand it.
correction in the second to last paragraph,
"Since the power supply can provide more current the amp’s actual power drops as speaker impedance goes down. This is just the opposite of those big He-Man amps."
It should read "... supply CAN'T provide more..." That should make more sense.
Jwrobinson - you are correct about how things are rated. I had a low buck Sony receiver rated at 60wpc into 2khz. No mention of 20-20khz rating. We have the same view on power supplies. Big supply means you have more power as the impedance drops. If the PS is just big enough for an 8 ohm load (ie it's current and voltage limited at 8 ohms), it will stay current limited into a lower impedance load. Do a little math and the amp is becoming less powerful as the impedance drops.
Of course this is a simplistic take on the subject and looks solely at output power, which we all know is not the best way to judge amps. I came up with this to answer my friend's question, "Is a 75w Rotel as powerful as my 100w Sony." This is a somewhat technical answer but my friend is an electrical engineer and who understand it.