Whoa, I shoulda built one of these a LONG time ago!! Holy crap, is this puppy cool! The build is pretty straightforward (Keith Vonderhulls' super-high quality PCB's are a big part of why), and everything worked on the first "light up". The three boost modes all sound excellent, though I'm partial (so far) to the germanium mode. The 3-color LED is quite cool, too, since you can always tell which boost mode you're in at a glance (red = germanium, blue = linear, and green = clean).

One point to make right away is that, despite the nomenclature, I wouldn't use the term "clean" for the sound of any of the three modes. The point of this pedal is to add gain, but to do it three different ways. Yeah, if you have things dialed down with a single-coil guitar on a clean sounding amp, you can probably keep the tone from the "linear" and "clean" boost modes pretty clean, as long as you don't run the pedal gain over about 50%. But that's clearly not what this pedal is about. You want clean? Use your amp and guitar volume knobs. You want drive? This baby's for you!

The "linear" mode is actually the cleanest, most transparent sound of the three. It's called "linear" because the boost is applied equally across the signal frequency range. You'll still pick up distortion, but it's of a pushing-the-preamp type, and doesn't have the character of the sound you get from an OD or distortion pedal, where the signal is being artificially clipped. It's a more natural and transparent sound. The distortion starts almost immediately with a humbucker guitar; it's already noticeable with the Level knob at 9 o'clock, before you're even at unity gain with the pedal. With single coils, you can get up around 12 o'clock before the signal distortion becomes really noticeable. It's already significantly louder than the unboosted signal, by that point.

The "clean" mode is actually the middle of the three, as far as degree of distortion goes. This mode uses a MOSFET for the gain boost, and it gives a nice lush sounding boost that seems to emphasize the mids and highs a bit more that the "linear" does. It also distorts the bass and lower mids to a greater degree, and sounds rather muddy on the low strings with humbuckers. But if you're looking to bust out of the mix with a solo up on the higher strings, this is a great way to do it.

The germanium boost makes no pretense at cleanliness--this one is all about hot, nasty top-end sizzle. The gain here is provided courtesy of an OC75 germanium transistor, and the circuit is based directly upon the Dallas Rangemaster treble booster of the 1960's. It's pretty noisy, so running this pedal mode with a noise gate of some sort is recommended, unless background "fizz" just isn't a concern. Keith added a nice additional feature for the germanium mode, which is a 3-way toggle that lets you vary the boost frequency range. The choices are treble, mid and full boost. The treble boost is just too trebly for my taste, but I can see where it would have its uses. The mid boost is pretty useful, generating a TS-style mid-hump but with a different distortion character. But the full boost gives you that germanium "hair" across the board, and is clearly my favorite of the three. Interestingly, the germanium mode also has the best bass clarity of all three boost modes, which I really didn't expect.

I'll try to get a clip or two posted in the next few days. My MIL is staying with us for a couple of days, having just had an angioplasty on Thursday, so peace & quiet are the order of the day around here for the moment.

I haven't finished the enclosure yet, and probably won't for a little while. Gotta have some fun with this puppy before I tear it back apart for painting & decaling. Besides, with only two knobs, it's not like the unlabeled controls are confusing! And that 3-color LED eliminates any ambiguity! Check out the pix below: