In the words of Strymon:

When we decided to develop an effects pedal that delivers the sound
and feel of our favorite tape echo machines, we knew we must
relentlessly study and faithfully recreate every last nuance. We spent
months in the Strymon sound design labs with an intense focus on
capturing the warm, saturated, distinctive qualities of tape echo
machines. The result is our hand crafted . Utilizing a ridiculously powerful SHARC DSP, every drop of processing power is harnessed.