The Siegmund Micro Tube Doppler Vibe is a tube version of the rotating speaker effect introduced in the ’40s with Leslie speaker cabinets. The Doppler Vibe uses a tuned and musically balanced circuit to get natural response from its micro tubes. It offers a range of speeds and intensity settings, while its Tone and Balance controls give tonal flexibility and allow shifting of phase balance. An optional foot pedal controls speed of the oscillation. The unit has outputs for Mono and Stereo, and is available in a rackmount version. Visit siegmundguitars.com.