old thread, but...
Brad Sarno is a really great engineer (both mastering work and builder of audio tech). I regularly ran into him when I worked retail in an acoustic music shop in St. Louis. He let me borrow an early Black Box when he was just starting to produce them. The original idea was that it was a buffer for pedal steel players in particular (he's a great steel player, and StL is the site of an annual international pedal steel convention), given that they would often run into impedance and line driving issues between pickups and volume pedals. When I tested it with acoustic pickups (mostly B-Band, Fishman, and LR Baggs at that time) it was a nice addition for lowering noise floor and improving overall signal quality (particularly in comparison to the lower of end of acoustic preamps like the Fishman beltpack units, Baggs Paracoustic DI). With my electric rig at the time, it didn't make as strong as a difference (early 2000s, right in the midst of the handmade true-bypass-looper era). A little more of the upper frequency range (3khz+), but not something I was personally interested in. For those with really large boards and signal runs, I can see it being a very useful and musical buffer. He's also produced a number of rack preamps (variations on Twin-style preamps mimicking J. Garcia tones), a few drives, and his stuff is used by a lot of jam bands (including Bob Weir, T. Anastasio, etc.), and pedal steel folks. But more importantly, he's an extremely humble and honest guy in an industry filled with a lot of BS artists; Brad's definitely not one of them. Not snake oil.
