Film-Tech Forum ARCHIVE: Ultra Stereo JS 5/95 surround problem

This is topic Ultra Stereo JS 5/95 surround problem in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Dan Lyons (Member # 1454) on 02-06-2007, 08:32 PM:

I've had a problem with the surrounds from this unit for quite some time. Sometimes they work, sometimes they sputter and hiss. (this happens in both non-sync and SVA mode)

Is my "surround eq and delay" card dead? I've tried re-seating it dozens of times and have since completely pulled it out since no surrounds are better than ones that sputter and drop out.

It's not the amp, i've switched them around, and all wires are securely tightended down.

Cheap fix for this or do I need a new card?
Unfortunately, throwing the Ultra Stereo unit out the window and getting a real processor isn't an option.

[uhoh]

Posted by Mark Gulbrandsen (Member # 72) on 02-06-2007, 08:43 PM:

The first place to start is to replace the Audio bypass switch on the format card unless its been done recently... bad audio bypass switches account for at least 65% of the problems I have with USL format cards. Also... look at the pins that make up the switch... if they are gold then its probably ok... if they are not gold pins then replace the switch no matter what, the switches contacts cannot be reliably cleaned no matter what!! We stock them by the bag full and they are cheap. E-mail me for easy instructions on how to do this without damaging the card. I just did one today and could have done a "quick how to"... thats a pisser. Next to go are the output delay relays... just remove them and jumper the audio track right on through. Almost all modern power amps have a delay on so you don't really need the O.P. relays in the USL. I am now beginning to have failures of the later versions of the O.P. relays(Aleph type) too so I am just eliminating them in booths where the power amps have a delay on. Beyond that you could have a bad card someplace anywhere from the decoder on out. Also remember that the signals pass through the format card twice!! 80% of the issues I have with the JS Series is always something in the format card.

Mark

Posted by Michael Schaffer (Member # 1204) on 02-06-2007, 11:29 PM:

The channel level trimpot?

Posted by Gordon McLeod (Member # 33) on 02-07-2007, 03:52 AM:

Also the bypass relays on the surround eq card caan cause issues