HammondWiki - Diff: Vibrato

Differences between version 2 and predecessor to the previous major change of Vibrato.

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Newer page: version 2 Last edited on March 11, 2005 1:02 pm. by
Older page: version 1 Last edited on April 9, 2001 1:59 pm. by
@@ -1,14 +1,13 @@
 !!!Hammond Vibrato 
 (Excerpted from the OriginalHammondLeslieFaq.) 
  
-Provided on the organs so equipped are __vibrato__ and __chorus__ settings ''V1'',''V2'',''V3'' and ''C1'',''C2'',''C3''.  
-;: ''[SpinetOrgans], at least the __M__ series, have only two vibrato/chorus depths: ''small'' and ''normal'' --- these correspond approximately to the '1' and '2' settings on [ConsoleOrgans].''  
-  
- 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 hammond 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, 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. 
  
 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. 
  
-In addition to the pitch shifting function, the vibrato, as implemented in the Hammond organ, also acts as a ''sweeping low-pass filter''. There is some frequency response and amplitude variation as the tap point of the filter is  
- swept. 
+In addition to the pitch shifting function, the vibrato, as implemented in the Hammond organ, also acts as a ''sweeping low-pass filter''. There is some frequency response and amplitude variation as the tap point of the filter is swept.  
+  
+Provided on the organs so equipped are __vibrato__ and __chorus__ settings ''V1'',''V2'',''V3'' and ''C1'',''C2'',''C3''.  
+;: ''[SpinetOrgans], at least the __M__ series, have only two vibrato/chorus depths: ''small'' and ''normal'' --- these correspond approximately to the '1' and '2' settings on [ConsoleOrgans].''  

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