Differences between version 3 and previous revision of Vibrato.

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Newer page: version 3 Last edited on March 21, 2005 7:31 pm. by
Older page: version 2 Last edited on March 11, 2005 1:02 pm. by
@@ -1,8 +1,8 @@
 !!!Hammond Vibrato 
 (Excerpted from the OriginalHammondLeslieFaq.) 
  
-Vibrato is the periodic ''raising'' and ''lowering'' of the pitch, and is thus fundamentally different from ''tremolo'' which is a variation in only the ''loudness'' of the pitch. The early Hammond organs featured a tremolo system however it was generally considered to not be very effective. The Hammond vibrato was invented by Hammond engineer JohnHanert. This vibrato is implemented using a tapped DelayLine: really a ''low-pass filter''. The signal is applied to the DelayLine and a rotating [Scanner], attached to one end of the [ToneGenerator] assembly, picks the signal off of the DelayLine at the ''tap points''. The [Scanner], a single-pole 16-throw air-dielectric capacitor switch, is wired so that the tap point will traverse the entire delay line twice, once up the DelayLine and once back down, for each [Scanner] rotation. As the DelayLine is traversed ''phase'' is added-to and then subtracted-from the signal. 
+Vibrato is the periodic ''raising'' and ''lowering'' of the pitch (frequency modulation) , and is thus fundamentally different from ''tremolo'' which is a variation in only the ''loudness'' of the pitch (amplitude modulation) . The early Hammond organs featured a [Tremolo] system however it was generally considered to not be very effective. The Hammond vibrato was invented by Hammond engineer JohnHanert. This vibrato is implemented using a tapped DelayLine: really a ''low-pass filter''. The signal is applied to the DelayLine and a rotating [Scanner], attached to one end of the [ToneGenerator] assembly, picks the signal off of the DelayLine at the ''tap points''. The [Scanner], a single-pole 16-throw air-dielectric capacitor switch, is wired so that the tap point will traverse the entire delay line twice, once up the DelayLine and once back down, for each [Scanner] rotation. As the DelayLine is traversed ''phase'' is added-to and then subtracted-from the signal. 
  
 The chorus signal is produced by adding non-pitch-shifted signal to the pitch-shifted signal. 
  
 The three settings each of vibrato and chorus correspond to different amounts of total delay thus different amounts of total pitch shift. 

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