Understanding the Tone Wheel Generator

The guts of it are this tone wheel generator that has 96 tone wheels on a rod, and they spin in an electric current.

How It Works

• Each time the little cog cuts through the current, a tone is produced.
• Each key has nine contacts which correspond to nine drawbars.
• As you press the key down, you gradually hear a transition from high to low.
  • The contacts engage one by one.

Key Mechanics

• In each key, there are nine contacts going up and down vertically.
• It's a very complicated system.
• I don't know how he came up with it, and it's amazing that they still work all this time later.

Historical Context

• The design is 70 to 80 years old.
• It's different from a church organ in that it's electric, to begin with.

Drawbar Modeling

• These drawbars are modeled on lengths of pipe from a church organ.
• The original idea was to recreate a church organ.

Drawbar Labels

• If you see slightly later models from the late 60s onwards through the 70s, the drawbars had the lengths of pipe written on:

  • This is 16
  • This is 5 and a third
  • This is 8
  • This is 4
  • That's 2 and 1

• Additional notes:

  • These are all kind of one and a third, two and three fifths.
  • I think these are sub fundamentals.
  • The white ones are all fundamentals.
  • That's a fifth, and these are all fifths.

Conclusion

It's an incredible bit of engineering, really. This model was made from 1955 to 1975.