I just got a 1969 soundcity MK 3 100w head.

I have a 2x12, assuming its wired in parallel with two, 16 ohm speakers.

The selection on the back shows I can have 4ohm 8ohm or 16ohm. Do I use the 8ohm setting?

Also, to change the setting, you have to take out the selecter and manually move it into the setting you want. Is this ACTUALLY how to change it, or am I not doing something right?

Last thing, there are 2 sockets next to the ohm selector...one of them is to connect the speaker to, but which one?!

Here is a link to the same as my amp, with "Speaker" written above one of the sockets...are they the same for all? What is the other socket for?


If you click 'find' and type this in...2.3: Sound City L100 Mark 3 Chassis Rear View

Thanks, Luke.
Yup 8 ohm setting. Just set the selector on the back to 8 ohms. The one closest to the left is usually the main speaker out. If you hear no sound turn it off and use the other output.
If you select the wrong setting, or you remove the load(the speaker) from the amp you can damage it.
Last edited by W4RP1G at Oct 21, 2011,