Hammond SKX Owner's Manual

Also see for SKX: Quick start guide Manual Introduction Instructions Reference guide

Contents

Hammond SKX Owner's Manual Manual pdf 49 page image

49Setting UpVIBRATO & CHORUSThe Hammond Vibrato & Chorus is another hallmark of the Classic Hammondsound. Vibrato alters the pitch slightly, as a violinist, singer, or guitarist may do. AndChorus combines a detuned signal with the original for a lush tone.[UPPER] buttonPressing [UPPER] button “ON” (red LED lit) will turn the Vibrato & Chorus effecton for the UPPER Drawbars.[LOWER] buttonPressing [UPPER] button “ON” (red LED lit) will turn the Vibrato & Chorus effecton for the LOWER and PEDAL Drawbars.NOTE: Vibrato & Chorus is available on 5 Organ Types; BType1, BType2, Mellow, Vx and Farf.NOTE: The mode, speed etc. of the Vibrato & Chorus effects can be fine-tuned. (P. 81)TO SELECT THE VIBRATO & CHORUS MODEVIBRATO AND CHORUS OF HAM-MOND ORGANSOn string instruments, the vibrato effect is createdby changing the string tension by one’s fingers.On wind instruments, by changing the strengthof breath. On electronic instruments with analogcircuitry, by modulating the oscillator. As the rota-tion of the Tone Wheels of the original B-3/C-3 wasstabilized by the synchronous motor, it was notpossible to provide a vibrato effect. On these mod-els, the vibrato effect was obtained by modulatingthe signal post-generator.The vibrato & chorus system of the original B-3/C-3consisted of a 9 stage delay line using LC phaseshift circuits. This produced a very short delayof about 1 ms. Tones were passed through coils,delaying the phase. Several coils were connect-ed in tandem and when the output of each tapwas passed from the top to the last by turns, thepitches gradually lowered. By taking the outputof each tap from the last to the top by turns onthe contrary, the pitch would gradually rise. Theseoperations were automatically made by turningthe scanner with a motor.The scanner was used to select one of multipleinput terminals by the static connection. As eachterminal was selected by the “blades” which ap-proached each other, a popping noise like that ofa switch did not occur and the signals of neigh-boring terminals cross-faded and switched them-selves.The mode-selection of vibrato effects was made bychanging the range of the connecting tap.As this system modulated the produced tonal sig-nals and not the oscillator, the original sound couldbe heard without the vibrato effect. By mixing thesound with the vibrato effect and the originalsound, the chorus effect was obtained.On this model, the chorus and vibrato effects aresimulated and modelled in the original fashiondigitally, by the DSP, without using moving parts.To select the Vibrato & Chorus Mode instantly, press and hold either the VIBRATO& CHORUS [UPPER] or [LOWER] button, and press any of the six buttons shownabove ([V1] to [C3]) to select the Vibrato or Chorus Mode you want.Vibrato & Chorus diagram of