This amp is low on features but high on sound quality at a bargain price. I bought one to replace an Arcam A65 which finally expired and was estimated to cost more than twice the price of the Cambridge to repair. Build quality is very good with a nice weighty feel to it, the volume knob turns smoothly and the input phono sockets feel solid, unlike some other budget amps. The sound quality is best described as neutral and hence is dependant on the quality of the original recordings. Volume in a mid size room through floorstanding speakers was more than adequate.
What the amp doesn't have is tone controls, a remote, a headphone socket or a phono stage. Never using the tone controls or vinyl and owning a headphone amp this doesn't bother me too much, although a remote would be nice. For some the lack of features will count out the AM1. If you can live with the spartan features it probably sounds as good as any amp in the sub £150 class.
Overall this is probably a 4 star product but a 5 star bargain.