For me it was two components. Back in the summer of 1976, I bought my first audio system... Harman/Kardon receiver, BIC turntable, and a pair of Advent bullnose speakers. I upgraded the BIC turntable for a B&O turntable. WOW!! what a difference, the B&O company were at their peak and this turntable was my venture into upper level audio.
The next component I added to the system was a Nakamichi 500 Dual Tracer cassette deck. It was the most advanced two-head cassette deck ever made.
The Nakamichi 500 is of special significance because of
newly-developed focused-gap type record/playback heads designed by
Nakamichi to give a far better head-saturation level than is found in
other two-head systems.
A young kid from a small coal mining town, this was the best audio system anyone would've been proud to own. For me to have been able to add a B&O table and a Nakamichi cassette deck, I wish I had the foresight to have kept these two components. However, I am truly happy with the system I have put together for the past four years.