Aside from Preamps and Amps:
Did Apple designers ever get into Audio Equipment?
Sony made some very nice PCs and Laptops, their Audio not as elegant it seems.
Recently I did searches on hifishark for 'Tandberg', and 'Bang & Olufson' and 'Bang and Olufson', some very cool designs I was and was not aware of.
Luxman has had a simple, practical, still elegant design look over the years
"Italian Speakers' yields some beauties