Nice little budget amps with a range of built in effects. Seem to suffer from intermittent sound loss and cutting out. The PCB are plagued with bad joints around ribbon cables, regulator U10, and although I have not seen it the numerous large resistors and caps.
Also recently saw one making g a terrible humming or buzzing noise. No signal was coming through at all. Current draw on the amp was about right so quickly able to link to open circuit power supply filter capacitors. Replaced, resoldered and glued into position and amp will be good as gold for another ten years minimum.