The Low pass Trimmer is useless as you have to make a wild guess for anywhere between min and max. Damping is not that good so you hear muddy / resonating sound after actual note has played. The build quality is not bad, I hope this is the smallest Hi-Wattage amp you can find in market. Though it is D class but it gets hot even when no music is playing and drwa about 2 Amps of current without any load / Music, and when you are actually playing loud music you need to make sure of air circulation around it.