This is a nice video where we can see a comparison between the cheapest and the most expensive pedal of the same type. Round Amp means that the guy is using a Fender simulation, just like the Joyo. I'm a long time Joyo A.S. user and i still like it a lot, i think for those who only need one clean sound to play direct is still one of the best if not the best pedal around considering the price. I'll probably buy the Mooer Micro D.I. to put after it, i've watched some videos and it sounds even better with an active d.i. with cab sim. The Palmer pocket amp mk2 is another option, i'll see. Cheers.