Before revision: Other applications Album art for Circuital, featuring a magic eye tube Magic eye tubes were used as the recording level indicator for tape recorders (for example in the ), and it is also possible to use them (in a specially adapted circuit) as a means of rough frequency comparison as a simpler alternative to Lissajous figures.
After revision: Other applications Magic eye tubes were used as the recording level indicator for tape recorders (for example in the ), and it is also possible to use them (in a specially adapted circuit) as a means of rough frequency comparison as a simpler alternative to Lissajous figures.