MOTM

Interesting...

Are patents renewable? 

I understand what you're saying about the technology used in 
something like the MS-20 filter being far from state of the art today 
but high-tech/low-tech it's still got a great unique sound.

Electro-Harmonix is a good example, they've probably got stuff built 
more or less exactly as it was 20 years ago.  So, there's nothing 
stopping someone from creating a Big Muff Pi clone and selling that 
even though EH is still selling them today - right?  I'm sure you 
can't use the Electro-Harmonix or the Big Muff Pi name - but other 
than that?

I guess 17 years is plenty to milk the cow, though.