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.

Hans Reichel performing in 2009

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. Part of the success of the Daxophone can be attributed to the detailed construction guide that Hans Reichel made.

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 difficult to access (see notes). ¹⁾

In the 1989 Guitar Player Magazine article ²⁾ as well as the Gravikords, Whirlies & Pyrophones entry on Hans Reichel, the daxophone is called a “dachsophone” and claims that “dachs is German for “Badger””. The early version of the instrument was called a Dachsophone, and the date of the change to Daxophone is unknown. The European Free Improvisation Pages has a short blurb on their Daxophone page that states the following “With regard to the name of the instrument, Reichel states that he had a Swedish LP called Mammal voices of Northern Europe, vol. 1 which featured wolves, rats, bats, fieldmice and also a badger (German: Dachs). Being impressed by the badger's great sonic range, the instrument was then given its name, with echoes of Adolphe Sax and then the 'chs' was changed to 'x', 'because I got fed up with having to keep on repeating the story'.” ³⁾

The 1989 Guitar Player Magazine article says that the Daxophone was invented in 1986, which is the same year as the below video, which demonstrates a very early performance of the instrument. Note the rather underdeveloped technique and sound as compared to later recordings of Reichel performing.

Two instruments are detailed in the 1989 Guitar Player Magazine article ⁴⁾, one with a wider electric guitar shaped body and one called the “Stick” which has a minimal acoustic body and is generally stick shaped. These two guitars utilize a 3rd Bridge. Reichel describes having discovered the underlying harmonic principles in 1980.

The instrument in the below video looks very similar to the wider of the two guitars discussed in the 1989 article but the instrument looks to have a number of additional pickups and a movable bridge present and looks to generally be in a different stage of construction. The video description also calls the instrument the Pick-Behind-the-Bridge-Guitar, which is mentioned but not explicitly shown in the 1989 Guitar Player Magazine article.

There are two guitars depicted in the 1989 Guitar Player Magazine article ⁵⁾ of guitars with additional frets added that go so far as to act as bridges across the sound hole of the guitars. These may represent some of Reichel's early experiments with playing mas many harmonics as possible on the guitar. These guitars are describes as being made in 1978.

Made in 1974, The instrument has a 3rd Bridge guitar on top and a more conventional guitar below. This guitar is described in the album notes of Lower lurum “although I don't like doublenecks too much, I've made this one for easy transportation. The part on the top is what I once called a 'pick-behind-the-bridge' guitar, designed to be picked on the 'wrong' side. Apart from this feature it is a normal solidbody electric. The strings are mounted in reverse, left-hand style. The bottom part of the doubleneck is a kind of hollowbody acoustic designed for finger tapping on both sides of the bridge. Besides a normal pick-up, it has a (piezo) contact microphone inside. Its strings are mounted right-hand style. On both guitars I use the thickest available strings. The tuning is regular but lower - starting on C or C#.” ⁶⁾

The 1989 Guitar Player Magazine article ⁷⁾ says that this guitar is played using an “electric razor”, which suggests that some of the unusual sounds of the instrument might come from the use of various tools.

This guitar is mentioned as “famous” in a short article by Daniel Fishkin about “Hans' Other Guitar” ⁸⁾ In which Fishkin also says that daxophone tongues were kept inside this guitars case indicating that both were important parts of his performances. This description comes from 2006, more then 30 years after the 1974 construction date.

This is a 3rd Bridge guitar shown in a short article by Daniel Fishkin. ⁹⁾ This guitar closely resembles another, unsubscribed guitar shown in an illustration in the 1989 Guitar Player Magazine article. Both appear to be of nearly identical shape and construction. The instrument in the1989 illustration shows two electronic pickups, 9 switches, and 9 frets on the “behind the bridge” space. The later model is made of a different kind of hardwood and has no visible pickups,has only 4 switches, and only 5 frets.

An instrument made in 1974 simply described as having “an extra pickup mounted at the nut.” is shown in the 1989 Guitar Player Magazine article ¹⁰⁾. No further information is known about the instrument but his interest in picking up sound from “the wrong side” of the guitar is a common talking point Reichel makes about his experimental guitars.

A short narrative about Hans Reichel by Daniel Fishkin and that details making a Daxophone in his studio ^{11) 12)}
Part 1 Introducing the Daxophone by Daniel Fishkin¹³⁾
Part 2 How to Build a Daxophone Soundbox by Daniel Fishkin¹⁴⁾
Part 3 The Mystery of the Acoustic Cantilever: Building a Dax for Your Daxophone by Daniel Fishkin¹⁵⁾

Again a link to the original PDF on how to build a Daxophone ¹⁶⁾

Crossing the Bridge by Hans Reichel, by Joe Gore that appeared in Guitar Player Magazine, 1989 ¹⁷⁾
This article details the names of many of Reichel's early instruments
Hans Reichel: born to be mild. Rubberneck, no. 16, pp. 4-11. By Chris Blackford, 1994
Gravikords, Whirlies & Pyrophones, ISBN 1559613823, pp. 12-13.

A very detailed biography on Musician Guide, this also has lots of links to resources. ¹⁸⁾
A shorter Bio from The European Free Improvisation Pages ¹⁹⁾
Almost all of Reichel's albums are available from the publisher Destination Out on Bandcamp ²⁰⁾

JLJ Instruments ²¹⁾
Daniel Fishkin ²²⁾

The original website daxo.de is not readily available because it was running adobe flash, if you have the ability to view the website using a lineage viewer, the original website is still viewable ²³⁾
Here is a youtube video detailing the website as it was intended ²⁴⁾

I find the video of Reichel's Pick-Behind-the-Bridge-Guitar really fascinating because the video is from 1986 which seems early for experimental guitars like this. This is a point that needs more research as I also think Bart Hopkin and Yuri Landman drew inspiration from these experimental guitars.