ST1200 optical sound repair

[Mark Mander]

Hi Àll,
not sure if you've ever had problems with the optical sound on the Elmo ST1200, I have several of these machines and one in particular is such a quiet runner that today was the day that I was going to take a look at the non working optical part of the machine,all the components seem to be working so I knew somehow the alignment must be the problem , it sounds an easy fix but after taking the optic lens out for a clean I realised that the two screws that hold the optic lens bracket on had a third screw for left and right movement, that's where the fun starts, it's either going to align in a few turns with luck or it's going to take a while. I was somewhere in the middle of this, first of all nothing ,no sound at all but just a buzzing from the speakers, then finally some sound from the film so I knew it worked, wooohoooo! After many turns of each screw we were getting close as the sound was there but not loud enough yet, a few more turns and the sound burst into life, this is where to get perfect sound/alignment you have to lock the 3 screws at the right point at the same time. Loud and clear sound after very fine tuning so I am very pleased, it will probably end up an optical sound only machine as it runs so nicely.

It's a shame I cant load pictures as reading it back pictures would have helped explain things clearer. Hopefully it's understandable as it's not the easiest thing to do, Mark

[Paul Adsett]

Hi Mark, it seems to me that optical sound design was an afterthought on both the ST and GS projectors. As you have pointed out the optical sound lens system is mounted by 3 screws. But adjustment is totally hit and miss because the screws are not at right angles to each other, so adjustment in one axis also affects the other axis, so you cannot adjust up-and -down and in-and-out alignment independently. So it makes alignment of the optical lens an absolute nightmare. Now that you have somehow achieved proper alignment I would lock the screws and leave it alone. No doubt Elmo had special equipment to align the lens correctly.

[Mark Mander]

Yes well and truly locked now Paul, just glad it's working, the holiday break has been put to good use repairing and servicing my machines.

I've just ran 600ft of Over the Top and a 200ft World on Parade and both sound really good, I must try magnetic now!!!

The optical sound on the ST1200 is much better than the GS1200, I'd say more of an afterthought on the GS, they all vary though maybe due to age and use?

Mark

[Lee Mannering]

Well done Mark!
Still got my old Over the Top as well its a great film on Optical as is Goldfinger.
Started collecting Opt late 80's when the old airline prints became available and the shorts. Particularly enjoy the 200ft Disney shorts and probably had 80+ films back in el day. One of the best sound tracks is on the 200ft German railway film ideal for sound testing. Deucherbahn.


For me and only my view in order of preference the Eumig M/O which is getting to be a rare little beast now. It has a wide capstan and virtually zero wow. A versatile machine.

2nd goes to the Fuji SD-AUTO. The optical sound is excellent on this machine very clear indeed.
3rd place for me goes to the Elmo GS800 with Optical sound and 800ft reel capacity. Lots of volume.
4th goes to the Fuji SH9 which I got from Gerald Mcnee way back. A handy little projector which has kept going and easy to maintain.

Each machine of course has plus and minus points but if you are looking for JUST OPTICAL the Fuji SD-AUTO is excellent and a quite modern machine thanks to Derann selling them in the UK. It'll do mag as well.

[Mark Mander]

I have a few other optical machines too Lee, Sankyo 800 opt/mag, Fujicascope SH30 which has very good optical playback but the lamps are getting harder to find and expensive compared to the Elmo's. A few more ST1200s plus the two GS1200s but the ST I repaired earlier is as new with barely any use hence feeling guilty it sat unloved for a few years, if I couldn't get the optical working it didn't matter but kept me busy today and pleased its done, 1.1 lens in now and looking good as it sounds, Mark

[Bill Phelps]

The last time I ran an optical film through my ST1200 the sound was barely audible....sounds like I need to do the same as you Mark and make some adjustments. I have 3 features and a couple shorts that are optical.

[Mark Mander]

Yes give it a go Bill, I had no sound at all so your closer to sound than I was to start with, try a clean first of the optical lens as it may help but if not very small adjustments is hopefully all you'll need, Mark

[Osi Osgood]

I had a heck of a time adjusting that darned lense, but it was worth it, but I never even thought of adjusting the brackets! Yay! Another project! Question, does these adjustments also correct wow or flutter with optical track?
.

[Mark Mander]

Osi
I think if the lens is aligned correctly then the sound should be clear and loud, wow and flutter might be another issue, fine tuning mine gave a flutter noise but I think it was picking up the sprocket holes so your issue could be that, Mark