If you wish, It´s also possible to build in a piezo pickup for amplification in the travel harp LUNA.
The K&K Big Twin Universal Internal has proven itself for this.
Description from K&K website:
"The Big Twin is a two-head piezo pickup, especially designed for bigger instruments with low mechanical resonance. The extra strong output signal makes it a versatile choice for a variety of instruments. The two heads allow for positioning at two spots which results in improved balance of the sound and a wider and absolutely flat frequency response. The Big Twin is recommended to transduce piano, grand piano, harp, dulcimer, double bass, cello and even acoustic guitars."
This pickup works pretty well for travelharp Luna without a preamp.