I have this pedal and love the boost mode which is not clean at all on my BB II. I'm confused.Marshall Bluesbreaker II on boost mode. This is a pure clean boost that doesn’t colour your tone.
I’ve been using it since the mid 90s. Works perfectly.
The Klon was one of the first boutique overdrive pedals that started this whole premium hand built pedal craze. Only 8000 were made in the 90s. A few famous people gushed over them, and the hype train got completely out of control. They were expensive and hard to get to begin with, but after they were taken off market, the prices started rising and have been continuously rising ever since. Now, the obscenely high price is part of what feeds the hype about the pedal.
In my opinion, it's the most overrated pedal of all time. It's just a diode hard clipper (like a RAT, DS-1, or Distortion+) with a very clever EQ trick up its sleeve. The frequency response changes as you turn up the gain, so it works as a gritty boost or an overdrive equally well.
Personally, I just don't like the sound of it all that much. There are a lot of better overdrives on the market these days, in my opinion. But when the Klon came out, there weren't many well tuned "transparent" overdrives available that cleaned up well when you rolled off the volume knob. The hype was probably justified back then (when the pedal cost only a few hundred bucks), but now? $1500 is a lot of cash for a simple OD pedal that does nothing all that remarkable.
If you want one, there are tons of clones available on the market. The cheapest is the EHX Soul Food for $69, and it sounds pretty close to the original. The main problem with the clones is that there is a "mystery" component (a set of NOS germanium diodes) that nobody has been able to identify with 100% confidence. That's really the only major sonic difference separating the inexpensive clones from the $1500 original.
But if you insist on having the right diodes, Bill Finnegan (the original designer) has reissued the pedal as the Klon KTR with the correct NOS diodes. The circuit is an exact replica of the original pedal with a few updates like switchable true bypass, and it sells for $269. Anyone who tells you that the Klon KTR doesn't sound as good as the original is a flaming idiot. Now that the KTR is available, I think anyone who buys an original Klon Centaur, for anything other than keeping it as a collectors item, is completely insane or has way too much money to burn.