Many pedals dabble in generating overdrive harmonics via symmetrical or asymmetrical clipping. When Jerry used tube power amps back in the '60s and early '70s, they were mostly McIntosh tube amps, and maybe early on they were actually the Fender power amp sections. Either way, these were all "push/pull" class A/B amplifiers that clipped "symmetrically" and incorporated plenty of "negative feedback". These amps were also fed fairly full bandwidth audio signal from the guitar preamp section, so the overdrive contained that information.
We designed the Earth Drive to operate along these same lines. Unlike the Tubescreamer or similar pedals that dump all the highs and lows, we preserve a lot more of the bandwidth, more fullness in mid-bass and more high end extension for that natural "transparency". Then we generate our clipping symmetrically like a McIntosh or Fender Twin power section to create the right balance and proportion of even and odd order harmonics. There's nothing like cranking and clipping a power amp, but the Earth Drive most definitely had late '60s and early '70s Jerry tones in mind. I find a lot of Jerry-tone players that are using very clean solid-state loud rigs that do a great late'70s and '80s tone, but don't really get a good Europe 72 or earlier. The Earth Drive is very much an attempt to make those early tones more accessible to a player with a loud, clean Jerry rig. I can't say it's the same sound as a Twin preamp into a Mc275 or Mc3500 tube McIntosh, but it's a practical solution.
... and it's just like any other day that's ever been...