I’ve had this one-of-a-kind fretted Rob Allen 4 string for just under a year. I’m only selling because I prefer playing medium- or short-scale basses. I plan to replace it with a Rob Allen fretted Mouse. The descriptions and photos below either paraphrase or plagiarize the for sale ads of a couple of the previous owners of this bass. Also reusing some photos from earlier sales. I hope the previous owners don’t mind. Please PM if there is a problem. This may be the only semi-hollow Solid 4 that Rob built. Rob is no longer taking custom orders, so this could be the only one ever. The internal construction is similar to his MB-2 and Deep models with chambering and a solid center block. The neck is quartersawn maple with a cocobolo fingerboard, the body is ash with nice contouring and a cocobolo bridge that matches the fingerboard. The pickup is the same single coil that Rob uses on his Solid basses, the knobs on the bridge are volume and passive tone (treble cut only). This bass only has a magnetic pickup, there's no piezo pickup. The underside of the bridge on the back has Rob's special aluminum string block, same as on the Solids. The scale length is 34", the nut width is 1-5/8" wide, and the weight is wonderful at 6.5 lbs. The finish on the neck is in great condition, it's thin and slightly glossy. The body finish has some light fingernail wear along the G string and some light wear down into the finish right around the E string side of the pickup - it makes a nice anchor for your thumb. The frets have very light wear only, just some light scratches from the roundwounds. The strings are D'Addario XL ETB92 tapewounds. We had a miserable long winter (like most of the northern half of the US) and I did have to adjust the neck when the action got too low. I’m hoping that the warmth and humidity now that spring has sprung will help. As of today, there is some fret buzz in the higher registers, around frets 14-20. Not a problem if you don’t typically play way up the neck. Here's a description with more details from an earlier owner: This Rob Allen is very, very special. It is a hollowbody solid 4, an oxymoron for sure. Basically, it differs from a "regular" Solid 4 in that: the lightest of light premium swamp ash was chosen for this build...the bass is insanely featherweight... it took Mr. Allen 3 attempts with different slabs of ash to get the body right...the top is cut, the wings have been hollowed out to the extreme, and then the top was put back on "drop top" style (seamless work, you can't even see it in the photos...check out the last photo!) with a beautiful F-hole the fretboard is not the usual rosewood, but rather premium cocobolo the bridge is made of the same cocobolo as opposed to a metal bridge the pickup has the same cocobolo cover and it is placed closer to the body as opposed to smack in the middle of the body the fretboard end is not a square block but rather an artistic S shape for just an extra touch of class The end result is what can only be called...organic. The bass sounds much more like a Deep 4 than a Solid 4, but it still maintains just an extra bit of presence compared to the Deep 4...it's really the best of both worlds. The top is charmingly "unfancy" (there are no indentations or thumbwear, what you see is the natural grain and coloration of the wood...it's really lovely). No need to gussy it up, the bass speaks for itself...plus, if aesthetics are more your thing, the fretboard is plenty beautiful and the linear design of the wooden bridge, pickup cover, and then board gives the bass a beautiful fluid continuity. The pickup is Alnico 2. Not as harsh or extended as Alnico 5, it sounds decidedly vintage and smooth. Very smooth. So much so that I actually desire a bit more harshness to really bring out the nastiness of some silicon fuzzes. This contributes to the character of the bass...not too much one way or the other...just a smooth bass with an ultra-detailed, complex midrange character. The neck is the real star of the bass. Simply perfect. Soft, invisible satin feel. The edges are rolled and feel worn in already even though the bass is a few years old. The fretwork is impeccable. The neck is made of perfectly quartersawn maple and has not needed a single tweak in very fluctuant weather.* The scale is a full 34" but because of the construction, it's actually a full 3" shorter than standard bass end-to-end, and it feels almost like a shortscale! The bridge is beautiful and simple. It features a volume/tone configuration. Tuners are Hipshot w/ a Detuner. Hipshot are, to me, the industry standard and have a well-deserved reputation for building some of the best hardware anywhere, hands down. *This no longer is the case. I'm taking the neck issue I experienced this winter into account with my asking price: $1,750 shipped in the USA. Includes Pro-Tec gig bag. I can provide more photos on request.