Design was (apparently) by the Onkyo Japan engineers... But images of earlier generations show the inside layout to be quite different, even though the overall specs are well nigh identical to the similar tier Onkyo/Integra's of the last 20+ years.My mistake, 11 amplified channels for the RZ70 (and I own the RZ70), I use outboard higher wattage power amps despite the outstanding measurements and listening impressions of the amps within it. For a variety of reasons I would never buy an Onkyo, but the the 50 & 70 were designed with Sharp Electronics, a giant powerhouse in electronics.
Much better heatsinking and boards, heatsinks, fans designed for cool running...
Not sure Sharp had anything to do with the design - they are the manufacturing partner only...