At the moment (2021) not much is known about the exact instruments that Hand Reichel built, with the exception of the Daxophone, which is a well documented instrument with many copies being made by various makers around the world. Reichel made many experimental guitars which are poorly documented.

The Daxophone is by far the most famous instrument built by Hans Reichel. The instrument has become a sort of icon for the experimental musical instrument world and is one of the few to be openly adopted and played by many experimental musicians.

Here is the Daxophone Information PDF taken from the now defunct Daxophone website. This document details the construction process for a Daxophone. I have taken the liberty of hosting it here since the original website is down. ¹⁾

There is some recordings of this instrument as well as this short video shown below.

A short narrative about Hans Reichel and details about making a Daxophone in his studio ²⁾
Again a link to the original PDF on how to build a Daxophone ³⁾

I find the video of Reichel's Pick-Behind-the-Bridge-Guitar really facinating because the