I found this circuit on a book ! Have anybody build this amp or know who design this amp ? How about the sound ? It stated Class A 100w(4ohm)N0-NFB . This amp original using 4 x 2SK405 , 4 x 2SJ115 and 2SC853/2SD261(one channel only) . I like to build it using 1 x IRF240 and 1 x IRF9240(one channel only).Keep saving $ and space ! Working or not working ? Please help me ! thank Q .