Film-Tech Forum ARCHIVE: CP-65 Multifader

This is topic CP-65 Multifader in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Steve Guttag (Member # 268) on 05-13-2000, 07:13 PM:

Hello all. I'm interested in your input/ideas...

I have a customer that wants us to make a fader system for his CP-65s such that Non-Sync gets it's own fader.

The reasoning is...whereas the music he plays in his theatres has a relatively constant level, the film vary widely. As such, he wants to be able to set the non-sync level and the feature level but have no interaction between the two.

I am considering takeing things a step further to make it a bit more universal...add yet one more fader for trailers (though it isn't needed or desired in this situation) so you would have three volume knobs (with tally LEDs to let you know which was active).

My question is, would anyone here also want such a device and what features would you want on it? (and please be serious).

We have also considered doing one for the CP-500 (having 4 preset fader settings that are cue selectable depending on how loud the trailer is but this one is loosing enthusiasum as trailers seem to be getting better.

Steve

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"Old projectionists never die, they just changeover!"

Posted by Brad Miller (Member # 2) on 05-13-2000, 09:00 PM:

Look at "battling loud trailers" in the tips section. That should suffice for his purpose. Just cue it a bit differently.

Posted by Steve Guttag (Member # 268) on 05-13-2000, 09:33 PM:

Brad,

Thanks, I already looked at your tip. For the bulk of our customer's that isn't robust enough (chance of it coming out of sync since it is a toggle). If I were to do something like that I would have it checking the formats to ensure the correct fader is in use at all times.

This is not to detract from your excellent idea...after all it IS a $5 solution to an annoying problem!

Steve

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"Old projectionists never die, they just changeover!"

Posted by Mark Gulbrandsen (Member # 72) on 05-13-2000, 09:41 PM:

Steve,
Its actually a good idea. I always thought that not having a non-sync level pot on a processor was stupid in the first place. I used to install 100K input level pots in the rack on the input of the non-sync all the time. This is not the best way to go with this but as long as lead length was kept short it worked fine.
Mark

Posted by Steve Guttag (Member # 268) on 05-13-2000, 09:51 PM:

Mark,

Which idea is a good idea? The $5 solution or just the idea of a separate non-sync fader.

The advantage of the separate non-sync fader is that the music would not suffer from the variances of the feature films.

Steve

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"Old projectionists never die, they just changeover!"

Posted by John Walsh (Member # 168) on 05-13-2000, 11:19 PM:

Copy the schematic from a Cat. 123 pcb and put it on a 1RU high panel. Do this three times. So, the panel will three volume controls with a led next to each one.

Instead of push button switches to activate each fader, have relay contacts. Configure it so each relay coil can be connected (via a jumper) one of two ways:

1. Connect the coil to the CP65's ID 'automation indicator' output. The idea is when one of the CP65's front panel format button is pushed (or the automation pulses,) one of the three faders becomes active. Jumpers select which format (mono, A, SR, Aux, NS, etc.)

2. Another jumper allows the relay coil to be controlled directly from the projector automation. That way a fader can be also selected by the cue reader or some external pulse.

I think if you press a format button on a CP65's front panel, it will automatically activate the local fader. So you would have to 'bang' the 'activate remote fader' line for each of the three.

A button to activate each of the faders could be placed next to each, for a 'just in case' possiablity.

If you can get at the fader ref. signals in the same way has a CP200, then you don't need to fuss with remote fader switching. Don't know a CP65 that well. Otherwise, set the CP65's wake-up to remote faders...
Also, when I say to connect the coil to the ID output, I know a transistor might be needed to beef it up.

Posted by Mark Gulbrandsen (Member # 72) on 05-13-2000, 11:41 PM:

I like the idea of the seperate non-sync fader. Its really a necessity if you are going to run anything in through it. I don't think the seperate trailer fader is a must though. Lets face it trailers usually suck no matter what.
Mark

Posted by David Johnson (Member # 173) on 05-14-2000, 05:03 AM:

You can do this with a CA21.
David

Posted by Steve Guttag (Member # 268) on 05-14-2000, 08:54 AM:

John thanks for your reply but....

Copying another's circuit design is illegal, if I came up with it independantly is one thing but to out and out take the circuit is just plain wrong.

Futhermore, I wasn't asking how to do it, just what features others might want in it besides the driving issue, that is, a speparate non-sync fader that is active whenever the non-sync source is selected (by any means) and a main fader for all other formats.

Steve

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"Old projectionists never die, they just changeover!"

Posted by Scott Norwood (Member # 30) on 05-14-2000, 09:51 AM:

I will point out here that the trailer-level issue points out one of the few advantages of the design of the SDDS system--you can run the trailers in SR (or DTS or Dolby Digital) and set the fader on the processor to something less than "7" while still leaving the SDDS fader at the normal position ("0") for the feature. (Though this does have the problem of making digital faults more obvious.)

I would say more, but it's almost 12:00 and I need to take time out of my busy schedule to go listen to Movie Tunes.

Posted by Gordon McLeod (Member # 33) on 05-14-2000, 10:53 AM:

I have done this same thing just using the tally LED to switch an opto isolater in the wiper of a set of faders so each format has it's own fader
But Steve Smart alredy has that in the Mod5 every format has its own level trim. Just replace the CP65 with a mod 5 noproblem

Posted by Joe Redifer (Member # 3) on 05-14-2000, 10:42 PM:

Tell him to get the CA21 automation with programmable remote fader. That way he doesn't have to deal with you at all

Posted by Steve Guttag (Member # 268) on 05-15-2000, 08:53 AM:

Thanks Joe! Why didn't I think of that? Oh wait...he doesn't want to change automations. Furthermore, I think I can come up with a cheaper solution. Not to mention, we would be his dealer for the CA21.

Also thanks to Gord for another SMART suggestion, but I think I will pass on that one too.

Steve

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"Old projectionists never die, they just changeover!"

Posted by Bill Purdy (Member # 202) on 05-15-2000, 11:11 AM:

Steve,

I did this one time. I used the format information outputs to select the appropriate fader. In my case the panel had a master along with 5 individuals. The individuals had a range of about +/- 6 dB. At the next ShoWest I had the thing in my booth along with a CP-55 (or maybe a 65) for people to play with. The front panel was lettered "Work in Progress - Comments Invited". I never got a single comment, pro or con. This is why it is not in our catalog.

Even though it was strictly a hand wired prototype on perf board, if you want it I'll send it to you for your amusement. It probably will still function.

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Bill Purdy
Component Engineering

Posted by Steve Guttag (Member # 268) on 05-15-2000, 09:29 PM:

Bill, that unit sounds pretty cool (and similar to SMART's Mod VI concept, ok Gord?) I don't think it is what the customer wants. But thanks anyway.

Steve

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"Old projectionists never die, they just changeover!"