Sound — 7
I will preface this section by saying that the Bassman tone is not one that is in my vocabulary, nor is it well suited to my playing style. For a guitarist into blues and classic rock, the FBM-1 could be the Holy Grail. There isn't really a pure clean setting with the gain knob; even with the knob turned way down, it breaks up a just a bit when you play really hard. This would be a perfect way to beef up an amp's wimpy clean channel. Turning the gain up gives you that "the amp is about to explode" feel of a cranked tube amp. There is no substitute for glowing tubes, but Boss has done a pretty good job of capturing the Bassman's character. There isn't much versatility, and the EQ knobs don't have a drastic effect between 0 and 10. My guess is that having tone knobs that can cut or boost by large amounts would get some very un-Bassman-like tones, and Boss seems dedicated to reproducing the amp's tone as fathfully as possible.
Overall Impression — 8
Boss created the FBM-1 with one purpose, and it is certainly a one-trick pony. The EQ knobs don't have the radical tone-shaping abilities that are typical of today's amps and effects -- but this, also, is true to the character of the Bassman. It was easy to get it to sound good; you just had to plug in and turn all the knobs to 10. This pedal is very much in that spirit -- plug in and jam!
Reliability & Durability — 9
Boss has not changed their overall pedal design much in over thirty years, and there's a good reason -- they're built like tanks! Practically every effect pedal from the venerable DS-1 to this year's brand-new offerings share the familiar boxy design. The switches are durable, the housings are bulletproof, and the pots will stand up to years of use. Feel free abuse the FBM-1 at your discretion.
Ease of Use — 9
Boss effect pedals are, in general, very easy to use. The FBM-1 has six knobs: Level and Gain are on one concentric pot, and Presence and Middle are on another. Bass and Treble are in the middle. There is one output jack, and two inputs: Normal and Bright, just like on the Bassman amp of yore. Dialing up a tone is as easy as twiddling the knobs until you get one you like. Just like in the old days! No menus, no programming, just knobs that you control with your fingers, not a mouse.