I'm not sure one should evaluate amplifiers by weight although when I bought my first CD player I didn't do any auditioning but just chose the heaviest in my (low) price range on the basis it probably had the best build quality. Little did I (or anyone else then) know that the SQ in CD players (and all digital sources) depends almost only on the clock, jitter and DA converters. Reading error even in a flimsy plastic 50c computer drive is only a couple of bits per million.
I doubt the anticipator circuits account for much weight, but compromised Class A working should allow some weight reduction as the power supply section accounts for most of the weight.