We're veering O/T with this, but legally you cannot copyright a circuit. You can copyright PCB, but if they reverse engineer their own from the schematic (can use exactly the same components), then in the eyes of the law, you're fine. Which is what Dano have done.
But yes, you're right, the entire pedal making industry is built on clones. The number of pedals out there that are variations on old tube screamer, muff or fuzz face circuits is astonishing (covers the vast majority of ODs and fuzzes). But at least they are usually variations where people have used different components rather than a like-for-like copy. I suppose the same could be said for the amp industry. So maybe my point is bollocks... hmmmm... I think I've argued myself into a corner.
In answer to the original question though, the last tube pedal I made (the Boob Tube), probably is as close to brief as I've ever got. It's a tweaked valve caster that overdrives my new very clean amp in a very natural tubey way. I really, really like it. Just going to tweak it a little more at the weekend. But it's nigh on spot on.
