What I use most of the time to look at watch movements and parts are a pair of high magnatification el-cheapo reading glasses and an AMSCOPE BINOCULAR MICROSCOPE. The most powerful eye loupe I know of is a SEITZ 20X loupe and is not only extremely expensive but is also virtually unworkable because it is mounted to your head. As the power increases the depth of field decreases and the slightest head movement will throw it out of focus. The AMSCOPE BINOCULAR MICROSCOPE has a rotating lens system that offers 20X and 40X. I will occasionally use a loupe for a quick look at something but for long periods I prefer the reading glasses and microscope.
How did you ultimately solve the voltage reduction problem?