Demo of the KMA Machines Strokkur Treble Booster
http://kma-machines.com/m_strokkur.html
My take:
The Strokkur is KMA Machines' take on the classic Rangemaster treble booster, with a few modern tweaks. In addition to the classic treble booster tone, you can dial in a more full range boost with the "range" control, giving you infinite tonal options. I tended to like the more classic sound, with the range control mostly to the left. In addition, you can fine-tune the shape of your tone with the passive treble and bass controls. Full disclosure: I'm not a "treble booster" guy. I generally am not quite sure to do with treble boosters. But I liked this thing a lot more than I thought I would. The sound is just so usable – it accentuates all the things you want (midrange and top) and dumps the things you don't need (bass). :-) Well built and really pretty too. :-) . Keeping it.