Standard SR-G24/G24A
A quick look at the back is the easy way to distinguish between the SR-G24 and SR-G24A. The SR-G24 (pictured in the center) sports a "PHONO" and an "EXTERNAL SPEAKER" jack to the right of the back cover's screw as well as a jack for an external power source on the lower right. These jacks were eliminated when the model was revised, giving the SR-G24A a less busy back cover.