If you are experiencing a popping or crackling noise after installing the Jaxlight you will need to check the secondary drive belt on the projector. When this belt badly worn or aging, it may cause a crackling or popping sound while playing back the analog sound track. This crackling or popping sound is only noticeable when running film, not during A or B-chain alignments.

GROUNDING: First and foremost the Jaxlight needs to be grounded properly. The negative screw of the exciter lamp bracket must be grounded to the casting of the sound head. This is extremely important; without proper grounding, a hum in the sound may occur.

Certain installations have ground loops in the projector/sound system configuration. A separate transformer (i.e.: wall wart) may be used in these cases to power up the line amp. A 9 vdc at approximately 250-500 mA transformer will suffice.

POWER SUPPLIES: Certain switching power supplies are designed to deliver more power than the Jaxlight consumes. This situation may cause the power supply to become unstable. To solve this, you may try installing a resistor in-line to create a load on the power supply. A 10 ohm, 25 watt resistor (or greater) will put enough of a load on these power supplies to stabilize them. Most switching power supplies, regulated switching power supplies in particular, do not have this problem.

STRAY LIGHT: Stray ambient light on the photo cell is a major cause of noise or hum in the system. Threading light, booth lights or any light source falling on the cell face will cause this. To eliminate the noise or hum, be sure threading doors on the projector are closed and that projection booth lights are off or turned down low. Very often you may be able to minimize this by rotating booth lights away from the projector or using a smaller wattage bulb.

OPTICS: Alignment of the slit lens, in reference to the Jaxlight is critical, and any miss-alignment may cause hum. Lens must be clean and aligned properly. The Jaxlight operates with any size slit lens from thick to narrow.

ROUTING OF CELL WIRES: The routing of the photo electric cell wiring is extremely important. Wires must be shielded, and installed away from any AC lines (as shown in the Jaxlight installation instruction sheet).

The modifications to the Jaxlight that I recommend to eliminate Static is as follows:

Separate Power Supply to power the Jaxlight pre-Amp Box. Suggest a 9-12 volt transformer that plug in to any plug on the console or plug. Eliminate the same Power Source as the Exciter Lamp.

The suggestions above had eliminated all problems of Static, and in fact you did not have to change any belts with Simplexes or Christie's Projectors.

Q: I have an older projector (1972) with a Zicon slit lens and Alton photo Cell , will a replacement bulb work with these optics?
A: Yes, If the slit lens works with your current bulb, (with distortion below 65db) then the bulb will work just fine. If the distortion is greater than this, the lens and photo cell probably should have been replaced already. (duh)

Q: While threading a new test loop, I noticed a high pitched squeal coming from the speakers (the sound rack happened to be on). I had run several movies and had not had a problem, however it continued while running the test loop.
A: You probably had the threading light on and ran the loop with the sound head door open. The Jaxlight system has a high optic boost and picked up the stray light. If you close the door or turn off the light this should solve the problem.

Q: When running a Cyan print there seems to be more distortion than with a Slivered print, is this normal?
A: One of the down sides to the Cyan sound tracks is increased distortion, however if SR is used with the Jaxlight this will reduce it below noticeable levels. All of the red light source systems have this characteristic. To help mitigate this we are offering a reduced price on our SR upgrade cards for Jaxlight users.