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    Working in the industry
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    In what was the greenest theatre in the land until someone painted it blue(Marina theatre, Lowestoft) doing more or less every type of job backstage (though not all at once, obviously).
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    Mark Holford

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gyro_gearloose's Achievements


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  1. Pretty sure that shoving an LED into a moving mirror was my idea from just over a decade ago. Wonder if I can get any royalties? 😁
  2. I should have been a bit clearer. One of the sound ops is mixing for broadcast, so would rather not hear the room at all! The shows run off timecode, so no traditional cues are given by the SM.
  3. At work we've got Beyer DT109 headsets for our sound ops. At the moment they have two headsets, one for comms and one for the desk. What I'd like to do is combine the output from the sound desk with the output from the comms beltpack, to get away from needing to swap headsets. Ideally I'd like a simple box that the comms, sound desk headphone output, and headset wired for stereo all connect to. The headsets mic would simply connect to the XLR4 plug into the belt pack. I don't want to mess about connecting comms to a desk channel, and I want only the sound op to hear the output from the desk. I'm aware that some comms base stations have an aux input, but that's no use for this situation. An off the shelf solution would be great, as long as it's not too expensive or clunky. However I'm not above building one from scratch, if someone could suggest a suitable circuit or two. Thanks in advance.
  4. I don’t work there anymore, but when I was last at the Marina Theatre in Lowestoft there was the old Vision 10 and the backup crate sitting unused in storage. I don’t think we ever had the software on disc, but you could always clone the hard drive. Drop them a message and I’m sure they’ll be glad to be rid of the thing 🙂
  5. We had this exact same problem a few years ago. The projector was powered from the shows distro on stage, while the sound desk and QLab Mac were powered from a different supply at front of house. This is usually fine, especially with the use of Cat5/6 in place of traditional analogue multicores. However as soon as the HDMI lead from the projector was plugged in to the laptop there was buzz from the sound system. In the end we solved the problem by running an extra power cable from their distro to the front of house mix position, thus eliminating the ground loop, and the buzz.
  6. Scroller cable seems to still be available. These guys appear to sell it by the metre.
  7. Acetate gobos in a Selecon Pacific might be more reliable if you need detailed/coloured gobos.
  8. Source four glass gobo holders go in the iris slot, not the metal gobo holder slot don’t they? Maybe the lamp peak needed adjusting because the glass gobo was in a different focal plane to metal gobos?
  9. If the lamps won't be visible, how about making up a flat plate covered in LED tape? You could use RGB or white tape, and there are plenty of low voltage LED DMX-able drivers out there.
  10. Stage Depot have some here. Not cheap though.
  11. If you are 30-40 volts continuously to the fluid pump, then you may have a dead Triac. Have a look at this thread from a few years ago when I was having some similar issues with our Unique.
  12. The CPU, stepper motor drivers, and logic and motor power supplies are all on the same circuit board so the fault won't be with the wiring. The drive current is controlled by four sets of three resistors in parallel for both pan and tilt. If there is a fault with any of these resistors then the driver chip will supply less current to the motor resulting in a loss of torque. To test your resistors you'll need to take the driver chip out of its socket and measure the resistance between ground and four other pins. There are four ground pins you can use (pins 5, 6, 17, and 18), and you'll need to measure the resistance from any one of these to pins 9, 10, 13, and 14. You should get about 0.5 Ohms. Anything higher than that means you have a problem. This method only works for the pan and tilt circuits as they use the PBL3772N driver chip. All other stepper motors use the PBL3775 chip which has the same ground pins, but you only need to check the resistance to pins 2 and 21, which should be 2.2 Ohms. Its well worth signing up to lightspares.com as they have part and circuit diagrams for all sorts of fixtures. They have the circuit diagram for both versions of Mac600s, for example, which will help you with troubleshooting your lights.
  13. Don’t bother getting your belts from Martin. They are a standard size/tooth profile, so you will be able to get them cheaper from engineering supply companies. These guys have probably got what you need. Are you sure it’s a mechanical problem? If the motor drive circuit develops faults, the motor will still turn but it will have less torque. This will make the motor lose steps if it’s trying to move the head too quickly, and will sound like the belt is slipping.
  14. If an otherwise perfectly working older Mac started having pan/tilt issues, I’d suspect the electronics if the mechanics all seem fine. I know from experience that the pan/tilt stepper motor driver circuit can develop faults with the current sensing resistors. Fixing those kinds of faults requires you to replace surface mount components, so I hope you’ve got a good soldering iron and a steady hand! @knightdan - what problems are you having with your Macs? Do pan and tilt work at all, or only at slow speed? Given the age of your Macs problems can arise for any number of reasons, such as motors being worn out, wiring looms breaking, faulty motor drivers, or the optical sensors failing.
  15. As and when travel is allowed again you should head over to Southwold pier near my home town of Lowestoft. They've got a mechanical clock that Tim made as well as the 'Under the pier show'. The chips are rather nice too.
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