This insanely clean early-70s “flip-top” or Portaflex amp was introduced in 1960 by Jess Oliver and became one of the most recorded bass amplifiers in history, famously used on countless Motown, Stax, and classic rock recordings by legends like James Jamerson and John Paul Jones. Starting in 1969, Ampeg updated the amp with Thiele-style ported cabinet designs and fresh control panels.

This one sounds fantastic. No doubt why it is used on some of the biggest records of all-time.