I don't agree at all that old Macs do not sound that great. The 275 is about the only vintage amp that will drive some of the modern high end saloon speakers out there satisfactorily on sufficiently dynamic material. Although its actual 80 watts are not really sufficient for a lot of these slutboxes. It is not the best tube amp for Klipsches and other quite efficient speakers. But I think hobbyists could build them if they had the amp and used some commonsense checklist methods building it.