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Wurlitzer 206A

S/N 127281L
Steve Graham

Service Log

3/23/2020

Continue to Regulate Keyboard Let Off

Adjust regulation capstan screw to have each hammer reach same height relative to bottom of reed before the hammer falls.  This evens out feel of the keyboard and strength that the hammer strikes each reed, evening out tone & note strength.

Voicing

Slightly raise or lower the metal sides of each reeds’ pickup bar to meet with the bottom of the reed.  Lowering pickup emphasizes fundamental while raising pickup emphasizes harmonics.  Also even out volume of notes

Add Vibrato & Auxillary Output

  • Remove piano’s selector switch pot – install new 50k pot w/ 18k resistor across lugs 2 & 3
  • Remove R57 12k from reed bar preamp
  • Change components on amplifier board (203724)
    • Remove C22 1mF
      (used for teacher microphone circuit & adds hiss)
    • Install:
      • R17 4.7k trim pot 1 & adjust to ~ 2:00
      • R13, R14, R15 680k
      • R16 10k
      • R12, R41 27k
      • R18 680ohm
      • R21 & R41 27k
      • R42 120k
      • R43 1.8k
      • R44 15k
      • R46 120 ohm
      • R47 56k
      • R48 180 ohm
      • Q3 & Q4 142083-2
      • Q15 & Q16 (later model versions)
      • C10 22mF 25v
      • C16, C17, C18  .12uF 100v
      • C23 1uF 25v
      • C24, C25 39pF 25v
      • C26 & R59 4.7uF & 25v  in series
      • C27 47uF 10v
      • LDR photoresistor
      • Jumper wire & posts

Image credits Crickers