Sound — 10
The Keeley BD-2 is a significant tonal upgrade from the unmodified Boss. Robert Keeley has taken a solid pedal with some pretty good tones and created an impressively versatile Overdrive. This Overdrive is not a tube Screamer replacement. The tonal results are transparent, dynamic, and full of character. The Keeley BD-2 responds remarkably to picking dynamics. By slightly altering your picking intensity and/or rolling back your volume knob you can clean this thing right up or you can dig in and rock it out. This pedal also works great for a lead boost. Because of the pedal's transparent nature you can crank the volume of the pedal, keep the gain down, adjust the tone and achieve a true preamp tube gain from your amp with a little added color from the pedal. This setting can also work great for adding a tiny bit of grit to a clean tone for thickness. The most surprising tone I found in this pedal is the fuzz possibility. Cranking the pedal's gain up and running into the clean channel of my Engl Screamer 50 I was able to get a total Hendrix vibe! It even worked great with a Uni-Vibe sound running into it. The PHAT switch is the only physical addition to the original Boss BD-2. By engaging this switch you will notice a slight bass boost. This tonal addition is more felt than heard. It is very useful for beefing up a 1x12 combo amp.
Overall Impression — 10
I've been using this Overdrive for about a year and it solved all sorts of tonal problems for me. I believe even Robert Keeley claims this to be one must have pedal. The Keeley BD-2 Phat Mod is highly versatile in it's full dynamic Overdrive range. It is also an excellent value ($150 street price)! Your guitar/amp relationship will be truly enhanced by the addition of this pedal. It works great in front of tube amps and solid state amps as well! Check out the audio clips and be sure to check out some of Robert Keeley's other little masterpieces.
Reliability & Durability — 9
I've had nothing but great luck with Keeley's products. Boss builds these things like tanks anyway! In the unlikely event that something goes bad on it, all you have to do is contact them and they'll fix her right up!
Ease of Use — 9
The Keeley Blues Driver (BD-2) Phat Mod consists of only a few features: Tone, Level, and Gain controls plus the added PHAT Switch and pretty blue LED. For those of you not familiar with Robert Keeley's pedal modifications, the Keeley website is definitely a place you should visit. I have found that his descriptions are spot on and very modest. As you will see on the Keeley site, several capacitors are replaced in the BD-2 for some increased bass response and clarity. Some of the diodes in the clipping section of the pedal are changed as well. This results in a different type of clipping (Overdrive) which really is more tube-like. All of that stuff is cool and all, but the coolest thing about this pedal is what it can do for your tone!