From what I'd heard and read about these pedals I was expecting the poor man's Sansamp. OK sounding but flimsy and cheap.
So what did I actually find? As to the Sansamp comment, I suppose it is valid inasmuch as I won't pay the price of one of their pre-amp pedals, so this is, if not exactly a poor man's, then definitely a tight fisted one's alternative. I have never played the respected Tech 21 pedals so can't compare the two, suffice it to say I've read enough from Basschatters who really love them to know they must be pretty good.
As to flimsy and cheap, well, it feels extremely solid to me, and the word cheap has two meanings; either inexpensive, or of poor quality. This is firmly in the inexpensive category, and not the poor quality.
It is very clean, my previous favourite the American Sound hisses like an angry kettle in comparison. As I type this I have the pedal on, presence and treble and level all up full, amp at gig volume and there is the faintest sussuration. Even taking the drive up to 75% there is very little to hear, knock it back a fraction and silence reigns. Impressive.
There's a blend control, which no self respecting drive pedal should leave home without, three tone knobs labelled bass, treble and presence but treat them as your basic B,M,T and you won't go far wrong. One complaint, the controls are black and notched at the ends but otherwise unmarked. Even here on my desk I can't tell if they're set to 5 to or 25 past.
With everything flat the BDI 21seems to warm and very, very slightly cut the sound. I found myself immediately easing up the level and the presence. If you like a really bright clanky sound you might find yourself reaching for the tone controls on your amp. However, where this little beauty really excels is in the drive sounds. It starts incredible subtly, just scuffing up and fattening the sound in a way which would work as an always on for when your amp and cabs are just too nice. From this starting point you can start adding all of those valve sound adjectives in ever increasing quantities. Fat, warm, grinding, dirty, rich, thick, filthy - yep it does them all.
I climbed through the gain settings with the blend at 50/50 , tone flat. At about 10 past you're in John Paul Jones territory, 1/4 past it all starts going a bit Jack Bruce, beyond that things start going totally Lemmy. Go back to midday with the drive, turn up the blend and you get much the same sort of sounds but at an earlier point in the travel of the drive knob. Oh and with much farther to go. Totally max both blend and drive and the sound becomes this tube train of noise. Utterly compressed, nothing leaking from around the edges, a viscous serpentine fluidity, and really quite, quite lovely.
A worthy addition to my ever growing pile of drive preamp pedals, I suspect they'd sell more if they doubled the price.