I've got an old "Studio Series" amp. I think it's the older version of the 22, and 22+. I bought it used about 10 years ago. It doesn't have the 5 band EQ, and the speaker had been replaced. The speaker looks like a Peavey. The one with the big magnet? Maybe a Scorpion? Either way, it sounds great! I've plated quite a few of the 22s, and 22+ amps, and actually prefer my older one. It seems to have a sweeter, rounder high end. Or, maybe I'm just more used to my own amp. I don't know. There is a difference in how the controls are layed out. The back has an effects loop, and a direct out, with a level control. I think that's the same. On the front panel, the controls from left to right are, volume, master, treb, bass, mid, reverb. I think the 22s have an extra master, or something. Has anyone tried the older amp?