You will be very interested in the Carver challenge [0]. In 1985, Bob Carver challenged the Stereophile magazine by claiming that he could perfectly reproduce the sound of any amplifier they chose by tweaking one of his (solid-state) amplifiers. They took him up with a high-end tube amplifier, and he won. Note that he did not use measurements but a brute-force approach of feeding the difference in output signal of both amplifiers to a speaker, and listening for (and manually correcting) any residual output.

https://www.stereophile.com/content/carver-challenge