Organ Settings

Tuning of Leslie rotational speed and acceleration

All men are equal – but Leslies are not 🙂 There is no such thing as the true unique real ‘Leslie speed’. Leslies all ‘turn’ differently, depending on the model, ageing of bearings, tension and ageing of belts (friction, slip), the chosen pulley of the horn, etc.

Grosso modo values are: tremolo (fast) speed: 360-400 rpm, chorale (slow) speed: 40-50 rpm.
Setting (slow/fast) speeds of drum and horn to identical values will result in a ‘church like’, rather ‘clean pulsing’ effect as drum and horn will be phase-coherent. Setting them slightly apart results a constant ‘phase shift’ between drum and horn, which makes the sound more vivid.

In real life, rpms of horn and drum always differ to a certain amount (on purpose or by imperfections / ageing) with the horn rotating faster. Changing the ‘pulleys’ of the belt driven horn changes speed about ca. +/- 10 rpms.

VR recommendation:  VR factory settings for VR Leslie speeds are faster than usual. If it pleases you leave it as it is.
If you tune the speeds yourself, one tip: set slow speeds for drum and horn 1-2 units (5-10 rpm) apart nd fast speed 1-6 units (5-30 rpm) apart

The following tables show examples of Leslie setting: ‘value’ is the number set in the VR menu (or CTRLR EDITOR), the braces contain corresponding rotations per minute (rpm) or ‘fall/rise time’ in seconds:

  • VR Leslie Type 2+3 factory setting::
      Woofer SLOW Horn SLOW Woofer FAST Horn FAST
    value (rpm) 12 (56) 23 (108) 62 (392) 99 (467)
      Woofer RISE Horn RISE Woofer FALL Horn FALL
    value (time) 36 (7s) 92 (1.2s) 36 (7s) 80 (1.7s)
  • CTRLR EDITOR default setting:
      Woofer SLOW Horn SLOW Woofer FAST Horn FAST
    value (rpm) 9 (42) 10 (47) 79 (372) 82 (387)
      Woofer RISE Horn RISE Woofer FALL Horn FALL
    value (time) 45 (5s) 91 (1.2s) 45 (5s) 83 (1.5s)
  • ‘Leslie 147’ (measurement by Mr. Fischer):
      Woofer SLOW Horn SLOW Woofer FAST Horn FAST
    value (rpm) 8 (35) 10 (47) 72 (340) 85 (400)
      Woofer RISE Horn RISE Woofer FALL Horn FALL
    value (time) 45 (5s) 91 (1.2s) 45 (5s) 83 (1.5s)
  • Averaged values of a couple of ‘real’ Leslies:
      Woofer SLOW Horn SLOW Woofer FAST Horn FAST
    value (rpm) 9 (42) 9 (42) 78 (368) 79 (372)
  • Neo Ventilator:
      Woofer SLOW Horn SLOW Woofer FAST Horn FAST
    value (rpm) 10 (48) 10 (48) 83 (390) 87 (408)