Checking output impedance

[SleepLess]

Hi!
I have just finished an 18 watt replica and I'm not really confident with the impedance selector I was given. I was used to another type. The sound comes out OK from the speaker but I'd like to know if I do get 8 ohms when I put the impedance selector on 8 ohms, and not 4 or 16 or possibly nothing...

Do you know of a way to do that? I tried to put my red DMM's probe on the hot terminal of the output jack with the amp turned on but didn't get any ohms reading...

Thank you!

[phsyconoodler]

You have to use your meter to measure each tap to the output common or ground.The one with the lowest reading is the lowest impedance tap. e.g. if one tap measures .02 ohms and the next measures .05 ohms and the third measures .09 ohms then you will know they are 4,8 and 16 ohms respectively.
  You have to have a good meter to measure successfully.A cheap meter won't read properly.

You can't do any checking with the amp on.Turn it off and unplug it for measurements.The switch is easy to check too.Just turn it to the setting you want to check and make sure only those terminals have continuity.