8mm Forum: ELMO ST-600 M Projector Sound Problem

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Posted by Thomas Beiter (Member # 470) on October 03, 2005, 08:42 AM:

All,

I'm new here, but ready to post my first plea for help. I recently purchased an Elmo ST-600 M Super 8 sound projector. The sound on the projector is extremely garbled. I've tried about 7 or 8 different films to make sure it wasn't the film. I searched this site for any answers and have tried the only answer I found (which was to create some slack in the pick up reel; didn't help). I've looked for adjustment screws to adjust the sound head, but didn't find any. The film is making good contact with the sound head, I've cleaned the sound head and all rollers with alcohol. I have the manual for this model, but it doesn't offer much in the way of troubleshooting this issue.

I'm out of ideas, anyone have any additional suggestions?

By the way, does anyone have any opinions on this model, good or bad? If I can't get the sound working myself, would it pay to have someone fix it or just get another projector?

Thanks in advance for any help,

Tom Beiter
St. Louis, MO

Posted by Craig Hamilton (Member # 258) on October 03, 2005, 11:42 AM:

Hi Thomas, this sounds very familiar to me. I had a similar problem last week on my ST-600 and had to resort to Kevin Faulkner for help. Below is what I done and it cured the problem.

With no film in the projector, set it running in forward motion with the lamp on. On the rear panel is a small square red button. Press this button in and then with it still pressed, press the record button below the UV meter. Then let go of the rear red button. The record button by the UV meter should now be locked in to the record mode. Press the rear red button again to release the record switch.

Repeat this process about a dozen times in quick succession. You do not have to leave it in record for long.

Apparently the bank of switches tarnishes with age and interferes with the sound playback. All you are doing with the above process is self cleaning the switch contacts. Since doing this on Friday I have had no problems with sound playback and my ST-600 has had a right hammering over the weekend with two continuous nights of film shows.

With regards to your question on the performance of these machines they are excellent little workhorses. Don’t despair if what I have said does not cure the problem. This forum is full of Guys with far more technical knowledge than me and I am sure they will have the answer to your problems. [Wink]

Craig

Posted by Kevin Faulkner (Member # 6) on October 03, 2005, 04:56 PM:

I think the thing for us is if you could tell us exactly what you mean by garbled. Does it go on and of or is it sounding like its coming through bubbles of water or the like.

Craig, glad that sorted your machine for you. [Smile]

Kev.

Posted by Thomas Beiter (Member # 470) on October 04, 2005, 06:25 AM:

Craig, thanks for your suggestion, unfortunately, it didn't help. I tried your method about 50 times, so I would think that would have been enough. I should tell you that the record button seems to be a little floppy. It doesn't lock in place with the push button. I can move it back up without pressing the button and pressing the button alone doesn't seem to want to pop it back up. Not sure if that has anything to do with anything.

I got bold and started messing with the 2 set screws on the sound head and by loosening and readjusting the sound head, I was able to get it clearer, but still very warbly. At least I can understand what's being said. There's not much adjustment that appears can be done, just up and down.

Kevin, it does sound like it's under water. More noticeable on the higher frequencies than the lows, it seems.

Thanks again for your help. I'm open for any more suggestions!

Posted by Kevin Faulkner (Member # 6) on October 04, 2005, 07:04 AM:

Thomas, I certainly wouldnt play with the sound head settings as that is quite a critical setup. Garbled sound could be due to insufficiant pinch roller pressure so that the film movement from the imtermitancy of the claw is not getting smoothed out correctly.
While the machine is running push down on the black plastic assay which houses the rubber pinch roller and see if that clears the problem. This is what normally gives this sort of grabled sound and not the position of the head. It's also possible the little head presser asay may not be pushing down on the heads so you should check that is moving down onto the heads in play. Its the 2cm black square assay with 4 small fingers which pushes the film onto the record/playback and erase heads.

Hope this all helps, Kev.

Posted by Thomas Beiter (Member # 470) on October 04, 2005, 08:26 AM:

>Thomas, I certainly wouldnt play with the sound head settings >as that is quite a critical setup.

Oops, hope I didn't do any permanent damage.

>While the machine is running push down on the black plastic >assay which houses the rubber pinch roller and see if that >clears the problem.

I will try that tonight.

>It's also possible the little head presser asay may not be >pushing down on the heads so you should check that is moving >down onto the heads in play.

That wasn't making real good contact which is why I thought adjusting the head would help. After making better contact, it does sound better, but still warbly.

>Hope this all helps

Definitely. I appreciate all the advice. I really want to get this projector working.

One thing I noticed on one of my films; I don't think it was the projector: the sound track was a good second or two behind the picture. Is that a common problem with Super 8 movies? All of the other movies played in sync with the pictures.

Tom

Posted by Thomas Beiter (Member # 470) on October 05, 2005, 07:02 AM:

Kevin,

I tried you suggestion of pressing down on the arm that holds the pinch roller. By applying *a lot* of pressure, I was able to remove a lot (but not all) of the warbling. So what's my next step?

Thanks,

Tom

Posted by Kevin Faulkner (Member # 6) on October 05, 2005, 07:43 AM:

Before we start to look at adjustments etc now would be a good time to make sure that the rubber pinch roller and capstan are clean. Use Isopropyl Alcohol on a cotton bud to do the cleaning and see if that helps.
Its has been known for some super 8 prints to have their sound out of sync with the picture. This is bad setting up by the lab who made the print at day one.

Kev.

Posted by Thomas Beiter (Member # 470) on October 05, 2005, 08:54 AM:

I have cleaned everything I can get to with alcohol and a swab prior, but I will try again. Would it help if I provide pictures of the sound heads/rollers/etc. or even a sound clip of what I'm hearing?

Posted by Kevin Faulkner (Member # 6) on October 06, 2005, 07:51 AM:

Thomas, Thats a brilliant idea. i will wait to hear from you.

Kev.

Posted by Brad Miller (Member # 2) on October 06, 2005, 11:10 PM:

Look carefully at the pinch roller too. Odds are it has one or more flat spots on it.

Posted by Dan Lail (Member # 18) on October 07, 2005, 12:30 AM:

Sounds like the heads need to be demagnetized. I've head tape recorders sound just like what you're describing. Do you have a demagnetizer. You can pick one up at Radio Shack for a couple of bucks. Just make sure the projector is unpluged while demagnetizing. It can hurt it. [Smile]

Posted by Thomas Beiter (Member # 470) on October 07, 2005, 10:42 AM:

Dan, the only demagnetizers I see at RadioShack.com are for a cassette player (where you run a cassette through it) and one for magnetizing/demagnetizing screwdrivers. What does a projector sound head demagnetizer look like?

Thanks,

Tom

Posted by Dan Lail (Member # 18) on October 07, 2005, 12:00 PM:

Thomas, I guess they don't stock them anymore. Here's one on eBay;

http://cgi.ebay.com/VINTAGE-REALISTIC-TAPE-RECORDER-HEAD-DEMAGNETIZER-MIP_W0QQitemZ5816432047QQcategoryZ15000QQrdZ1QQcmdZViewItem

Here's one with a Buy-It-Now of $24.95. I think that's a bit much;

http://cgi.ebay.com/New-DM-10-Tape-Head-Demagnetizer-for-Studer-Revox_W0QQitemZ5813742805QQcategoryZ15000QQrdZ1QQcmdZViewItem

I may have an extra one, but it wou;d take some time to find it.

Posted by Kevin Faulkner (Member # 6) on October 07, 2005, 06:08 PM:

From the recording of the soundtrack that Thomas sent me it sounds like a bad case of flutter on the sound track. Its the sort of thing you would get if the loop under the lens was too small or the pinchroller wasnt smoothing out the motion of the film very well.
I would say form what I heard that the heads are sounding ok and dont need demagnetising.
I have asked Thomas to do some other checks so we will see what he comes up with.

Kev.

Posted by Thomas Beiter (Member # 470) on October 20, 2005, 07:04 AM:

With Kevin's excellent guidance, the Elmo Sound problem has been resolved. As it turns out, the flywheel on the backside of the capstan was missing, along with the spring tensioner, washer and pin that holds it in place. I contacted the seller and he said he had removed it to look at the gears and forgot to put it back on. He shipped it to me and I put it on last night. Everything works beautifully now. Thanks for everyone's suggestions, while only one answer solved the problem, they all lead to the solution and were all appreciated. I know a lot more about Super 8 projectors now.

Tom

Posted by Jan Bister (Member # 332) on October 20, 2005, 06:59 PM:

Amazing... I've heard a few things, but the flywheel missing? Glad it's all sorted out for you now, though you surely must have wondered why your projector seemed so lightweight at first. [Big Grin]

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