Hi Rod!
That’s an excellent question. 
While it’s easy to get a great tone for nagauta shamisen, it’s quite challenging to get the sharp, “electric-like” tone for a tsugaru shamisen. The main reason is the common type of skin used for the style is dog skin. From what I’ve heard, dog skin is much denser than calf skin (or other commonly available skins) and so the sound comes out much sharper and clearly than other skins. Shamisen skinners (like Shamisen Katoh) use thinner dog skins to be able to get a crisp sound with the wooden kisen.
However, recent production of dog skin has stopped completely (due to political factors), and so the producers are now producing goat skin with the same process (You can read more about it here - Vintage Tone (Natural Skin)). Using the same treatment process results is a similar tone as dog skin. Not exactly the same, but pretty close. Unfortunately, achieving the “tsugaru tone” with goat skin requires stretching it much tighter than possible with wooden kisen. As the tsugaru aesthetic demands tighter and tighter skin, metal machines are used to clamp and stretch the skin stronger than possible with wooden clamps.
I’ve tried for many years to get the tsugaru tone with wooden kisen and calf/goat skins, but I never achieved good results. (I mean, it sounded nice, but not the same) Things only changed when I finally invested in a machine (shown above) to be able to achieve those high tensions with goat skin (Vintage Tone) or synthetic skin (Hibiki), which has a brilliant tone for tsugaru style.
Cheers!
Kyle