I just got this pedal today and after 10 seconds of playing thru it, I really dislike it. It seems that Darkglass likes their pedals to have a large and obnoxious mid bass bump in their frequency response. This one actually hurts my ears to listen to it. Its controls consist of a Blend, Era, Drive and a Level (overdrive output). In my opinion, the 'Era' knob should be called "really muddy to a bit less muddy".
It's tone reminds me a of Lindy Fralin pickup, only the Fralin is a bit less harsh. It doesn't sound like 'tubes' being pushed, but rather like someone threw a blanket over your amp. It leads me to believe that this pedal is designed for bass players that have tweeter in the cabs, but I've always found that tweeters and overdrive/distortion pedals are NOT a good combination.
I'm sorry to say this, but I like this one even less than their B3K and I didn't like that one at all. All the dirt side did was add this ugly, heavy mid bass tone that ruined my clean tone and every time that I bypassed the pedal completely, I had a smile on my face. I when turned the Era knob completely counter-clockwise, I found the tone to be unusable (unless you like mud), and fully clockwise, it still had the obnoxoius mid bump. I find it hard to believe that there are so many bass players that love this pedal, so I pretty much immediately sold it after unsucessfully spending quite a bit of time trying to get a decent sound out of it. It's the worst sounding overdrive that I've ever owned, so i have no regrets parting ways with this one.