I've always been a fan of classic tone from the 1960's and 70's. Some of those classic tones came from the Rangemaster trebleble booster. The Holy grail of the Rangemaster tone is the Beano album from Eric Clapton's brief stint with John Mayall. In my opinion it was one of the first modern rock tone. It was a Les Paul into a Marshal combo driven into creamy organic sagging overdrive by the Rangemaster. The Java booster will give you this tone. Period. This pedal needs a tube amp that is already breaking up for the creamy magic. Don't think that you can make the magic with a clean 65 Twin Reverb. Won't happen. Don't think that you can make it happen with a solid state amp either. It must be a tube amp that is already breaking up for optimum results.
The sound quality of this pedal was evident with the first notes that I played. I used my Gibson Les Paul into a Marshall Vintage Modern with Greenback loaded Marshall cab. WOW. Beano tone was there in spades. I could get into the Iommi ballpark easily. With my 70s reissue Stratocaster, I got Blackmore tones. I then played it through my Vox AC30c2x and the May tone popped out. Amazing. Instant gratification.
It's a simple pedal with high quality build and parts. Two knobs and a toggle switch. The original Rangemaster had just a boost know. The keely has an additional Tone knob which is great to give you more control.
It also has a toggle switch with B, M and T position. The middle position is the classic Rangemaster while the other two change the characteristics of the boost. This also great to have, but the default classic boost is pure bliss. The other two in the manual are called 'Full range' and 'mid range'. I llive the fact that you are getting three boost pedals or perhaps a Rangemaster with two additional mods along with the classic in this one pedal. And with a tone cut knob, you can get the sound you want with different TUBE amps and guitar pickups.
The pedal is pricey but I figured if I am going to get a treble booster, I may as well get one of high quality and one that nails the classic tone with additional knobs and boost mods.
Great pedal. Please play through a driven tube amp if you get this.