The Taurus wasn’t a major project, but a handy companion piece to the Gemini, an earlier Stylophone modification.
The problem with the Gemini is that it has two voices, output in stereo, but, typical of the Stylophone, it has only the one speaker. This means that some of its effects are only available via the stereo line out.
As a result of much past experimentation, I have many Stylophone bits left over. To make the Taurus, which was to be a very simple external amplifier, I used an empty case, some spare grille material, two amplifier circuit boards and two speakers, all from S1 reissue versions of the instrument.
The Stylophone grille isn’t glued down, and can be removed from the inside by pushing out half a dozen lugs which hold it in place. I did this first, cut a hole in the top of the case for the second speaker – vaguely matching the hole through which the original sounds – and refixed the grille.
The picture shows the second speaker glued in place, and the two amplifier boards connected to a new stereo input socket, the battery box and the speakers:
I wasn’t using any of the original keyboard, switch and socket parts, so I glued some spare grille sections inside the switch and socket holes and outside over the hole through which the keyboard is normally accessed.
A small tripod was attached to the base to enable the speakers to be angled for better distribution of the sound. Decoration consisted of astrological symbols, in the style of the Gemini, and matching black and white bulls, front and back.
It works well with the Gemini, which has its own volume and mix controls, but is a very basic unit indeed – no volume control, no on/off switch and no external power socket: it uses three AA batteries like the Gemini itself, and could be useful with other instruments needing a slight volume boost and not connected via a line out socket.
[Edit: the Taurus now has a volume control, which I should have put into start with. This makes it much more practical to use.
As it uses a pair of Stylophone amp boards, I’ve done exactly the same as the Stylophone, and put a 10k log potentiometer at the input – in this case a dual, one for each channel].