cliparts/c/c/3/2/clipart-tube-only-please-cc32.svg image/svg+xml Open Clip Art Library Tube only, please! 2011-08-02T09:50:39 Joke sign for apologist of warm tube sound. http://openclipart.org/detail/153253/tube-only-please!-by-boobaloo boobaloo amplification audio circuit circuit diagram clip art clipart electronics lamp pictogram radio symbol triode tube