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SX4 | Specifications | Instructions | Applications | Purchase | Help



  1. Loosen the Captive Retaining Screws (These captive screws will loosen but not come out).
  2. While pulling on the Effects Drawer, release the Safety Latch and pull out drawer from the SX4® Housing.
  3. Push the Tension Roller towards the Drive Roller until it engages the Tension Roller Catch and holds it in the loading position.
  4. Slide the Fixable FX/Loop over the rollers. (Due to the small space between the roller assembly and the inside of the housing, the loading is easier if the housing is sitting on the edge - not resting flat). Some of the more open loops, such as fire and clouds, tend to catch on the shoulder of the roller. Sometimes it is easier to advance the loop around the rollers as you are loading to clear the inevitable snagging of the loop.
  5. Be sure the FX/Loop rests between the brass shoulders of the drive roller.
  6. Release the Tension Roller Catch slowly and allow the Tension Roller to extend fully. (Don't allow the roller to snap out - this could damage the loop). Confirm that the loop is making square contact with the rollers.
  7. Connect Power Transformer to AC Power 120(120 volt, 2-Pin Edison) male, or 230 Volt (European). Then connect 3-pin female XLR to FX/Loop Tray. Power Transformer can be plugged directly into the AC line or into a dimmer. Plug the unit in and confirm proper functioning.
  8. Install the Effects Drawer into the SX4® Housing - The drawer will have a positive snap when the safety catch is engaged.
  9. Tighten the Retaining Screws. Make sure the screws are fully seated.

NOTE: It is important that the screws be tightened
completely, DO NOT depend on the safety latch to hold the Effects Drawer securely.


The unit can be oriented with the FX/Loop running horizontally, vertically or any direction in between. Loosen the retaining screw and knob. The barrel can be adjusted about 25o on either side of vertical. Loosen the barrel screw and knob more to adjust beyond 25o.


The FX/Loop runs in two planes separated by about 1.25 inches. The lens can be adjusted (by sliding the lens tube in and out of the barrel) to focus on one plane or the other or somewhere between the two. Focus on one plane will leave the other plane very much out of focus and gives an unambiguous direction to the effect.

Focus between the two planes leaves both out of focus. Many effects, (even the most realistic) benefit from being a bit out of focus. Other effects yield surprising results when very out of focus. It's worth the time to experiment. Also worthy of experimentation is to use another moving effect (the GAM TwinSpin II or the GAM Film/FX) in the iris/FX slot. This too is on a different focal plane than the film loop, but as you will see, it can offer some unusual effects.



GAM Product #TS6100
Rosco Product #206 36100 0120

Click to view separate spec sheet or download PDF
GAMChek Jr. Spec SX4® LOOP TRAY Instructions

GAM SX4 Loop Tray


The SX4® has a built-in Forward/Reverse Switch for the occasion when the chosen focus effect works well on one focus setting but the effect is traveling in the wrong direction. There is also a two-speed control knob that can be used with a dimmer.

The SX4® has a built-in Forward/Reverse Switch for the occasion when the chosen focus effect works well on one focus setting but the effect is traveling in the wrong direction.

Attach a safety cable to the safety loop on the bottom of the Effects Drawer and to the yoke or light pipe.


  • For longest life and for the most effective image, be sure to adjust the centering and flatness of lamp field - NO HOT SPOT IN THE CENTER
  • Hot spots will cause uneven heating and wear on the FX/Loop and shorten their useful life.
  • Always have the FX/Loop in motion before the light comes on. Don't allow the FX/Loop to be still in the gate with the lamp on as this will allow one section to heat up and will shorten the life of the loop (especially if focused on the seam).
  • Shipping and Storage: To prevent damage to the screws or to the mechanism, be sure the drawer retaining screws are tightened securely.


  • Pin 1 = Common
  • Pin 2 = FAN +12v
  • Pin 3 = Affects Motor /Speed Control +12v


SX4 Connections diagram

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