my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Sound issue with a Jax lite (Page 2)

This topic comprises 2 pages: 1  2

Author Topic: Sound issue with a Jax lite Josh Jones Redhat Posts: 1207 From: Plano, TX Registered: Apr 2000 posted 11-17-2003 07:27 PM                        you may also want to see if you are experiencing microphonics, that is noise induced by mechanical vibration, usually manifesting itself as a 'ringing' noise. Is the noise audible with no film in the machine and its running? When its not? if there is a difference, you've got microphonics, and the cure would be to tighten down all the parts in the optical assembly, the cell, the lens tube, lamp socket, and make sure none of the optics are loose in their holders, like a lens in the slit tube being loose or something. Also if the pre-amp is oscilating, try better seperating the input and output leads, as capacitance could theoretically cause it to oscillate. Josh  |  IP: Logged Matt Zeiner Expert Film Handler Posts: 146 From: Windsor, CT USA Registered: Sep 2003 posted 11-17-2003 09:45 PM                     You probably already did this, but - did you try the projector 2 input? Swap the NR card? Look for cold solder on the main board? Does sound like arcing is going on somewhere, tho... ("The processor was all the way up and so where the amps. As I got through the first reel and half way through the second, the sound kicked in to where I had to turn it down")  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 11-18-2003 12:46 AM                     To eliminate the question of mechanical vibration (microphonics) and/or AC appearing at the output of the exciter supply run the projector with no film, turn on the sound system and stick a piece of paper or a business card into the path of the light beam and block it. If the problem goes away when the beam is blocked you know what the problem is. If it doesn't you have eliminated all question on that front.  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 11-18-2003 08:06 PM                     Possibly the Rubber isolation gromets are dried out and transmitting vibration into the slit and jax light  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 11-18-2003 08:20 PM                     Good Lord guys, this isn't even worth dwelling on..... get rid of the thing and just go back to a regular solor cell and exciter light and your problems will go away! Mark  |  IP: Logged John Eickhof Jedi Master Film Handler Posts: 588 From: Wendell, ID USA Registered: Jan 2000 posted 11-18-2003 09:48 PM                        Actually, I have only had two simular problems to this one with the JAXLITE, (I have at least 3 dozen in use) Bothwere with a RCA, the lens on the jaxlite had loosened..On one, the customer simply took a liitle hobby cement and re-glued the lens to the JAXLITE, The other I did myself, the trouble was gone! I have discussed this with Jack Cashin and since his LED array develops a hight temperature they had trouble with the glue failing on the plastic lens. Give it a try! Good luck!  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 11-18-2003 09:48 PM                     I had a projector in North Carolina that made a "Ping-Ping-Pingity-Ping!" sound as it was running. No film. Motor running. Sound processor on. Jax-Lite running normally. I could even see these spikes in the scope. I worked on it for HOURS trying to figure it out. I took the whole thing apart and reassembled it at least two times. Turn out that the drive belt between the motor and the sound head was worn out. The little threads hanging off the edge of the worn belt were hitting against the edges of the drive sheave, making a high pitched "Ping!" sound as each one struck metal. I replaced and ensured proper alignment of the belt and the problem was solved in minutes what took me hours to figure out. Yes, I would vote for the complete abolition of Jax-Lites but face it. They are here. Theaters are never going to get rid of the damn things. SOMEbody's got to know the tricks to fixing them!  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 2 pages: 1  2

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.