8mm Forum: Eumig Sound Head

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Posted by Martin Parker (Member # 4966) on July 23, 2015, 05:36 AM:

Hi all, My first post and already asking for advice - hope thats ok..
I have recently purchased a Eumig Mark S 802 D which has muffled sound. I have taken the head assembly out of the projector and removed the spring steel cover which allows the pressure pad and track to come away exposing the heads. I gave them a clean with servisol - they were actually pretty clean - and manually ran some sound film passed the heads which sounded ok . I reassembled the unit and again pulled some film through and got a reasonable response from the heads. When I put the unit back in to the projector and ran film through it was exactly as before - very muffled and virtually inaudible. I haven't touched the locked screws which adjust azimuth etc and they are still locked from manufacture so I am reluctant to touch them, although I am tempted. The fault is the same in super and standard 8 mode so it must be something common to both sets of heads. Any one have any ideas? Thanks in advance, Martin

Posted by Andrew Woodcock (Member # 3260) on July 23, 2015, 07:23 AM:

Hello Martin and a warm welcome to the film forum from myself and us all, I'm sure.

I haven't owned your model but I knew Eumigs heads were never deemed the most durable.
Silly question, but are you sure the head isn't just worn out?

Also I have never heard of Servisol being used as a head cleaner,not if it is the type I'm thinking of.
Isopropyl alcohol cleaner is generally what is used unless your can of servisol is this type of substance?

Posted by Martin Parker (Member # 4966) on July 23, 2015, 07:51 AM:

Hi Andrew, thank you for your kind welcome and reply. I too have heard that Eumig heads can wear out , but my gut feeling is that in this case they are ok. When i manually pull some film through I get a good frequency response although you can't actually make out anything because its not being pulled at a constant speed, it only seems to go muffled when back in the projector. I have looked at the mechanism that engages with the pressure pad when loading at that seems to retract the pressure pad correctly although it does sound as though the film isn't properly tracking over the head which makes me wonder if the azimuth adjustment is out. I am reluctant to adjust it because it is factory set.
I have used servisol before and it works quite well for head cleaning, it is essentially a contact cleaner and is great for scratchy volume controls and headphone jacks, I have had a couple of cans for years , I don't know if you can still get it, but it has served me well. I may try some isopropyl alcohol as well just to be sure.

Posted by Andrew Woodcock (Member # 3260) on July 23, 2015, 08:02 AM:

You could try demagnetizing the head and your switch cleaner is the one I use for circuit boards and switch cleaning etc.
Try using Isoclean also Martin, this is purpose built for head cleaning.

I'd do both these before adjusting the head angle as it is from the sound of things still at factory setting.

Try to visually inspect the head by using a dentist mirror if you cannot remove it easily.

Beyond that I'd try side to side alignment and checking the pressure pad setting and pressure applied and alignment before altering the azimuth.

Posted by Maurizio Di Cintio (Member # 144) on July 23, 2015, 04:35 PM:

In addition to the four front sealed screws on the head mount for adjusting tilt, azimuth etc of the sound heads, there is another tiny screw to adjust the relative position of the sound pressers. This particular screw sits on its own, just a few millimiters behind the head housing: it is yellow (possibly made of brass?) and faces downward. If you look at it carefully, you'll note it is slightly eccentric and this enables it to move the whole sound pressers assembly so that the pressers can be fixed in order that they press exactly where they are supposed to press, e.g not too before and not too past the heads' gaps. Check if the seal on this very screw is stil present: if it's not, perhaps turning it in a way or another might solve the problem.

Posted by Martin Parker (Member # 4966) on July 24, 2015, 05:41 AM:

Hi Andrew and Maurizio, thanks for your help and advice I found the little screw and adjusted it "live" while running a film but sadly it didn't seem to make any difference, I really thought it would as it sounds like an alignment issue. It almost sounds as if the film is running backwards ( I put the projector in reverse and it sounds the same ) The heads look clean under a magnifying glass , it is almost as if the pressure pad is not pushing the film up onto the heads. I don't have a service manual for the Eumig and have looked on the website but I can only find a user manual , I wonder if one exists anywhere?
Thanks again, Martin

Update: The problem is caused by not enough pressure being applied to the film. I pressed a screwdriver up against the exit of the head on the plastic pad and got clear sound ! it required quite a lot of pressure so I will take the unit apart again and see how to improve the pressure on the film. The pad is retracted by a metal tag when loading the film so I will investigate that to see if it is closing properly .

Posted by Maurizio Di Cintio (Member # 144) on July 24, 2015, 10:08 AM:

Yes MArtin, with the added info it sounds like the system to retract the pressers during film loading, is not permitting sufficient pressure strength during regular projection. You should check for dirt in/around/across the pressers block and that the pressers retracting system moves freely all the way through. Also check the metal arm in the projector, which is linked to the main rotary selector and to the loop former: it should have a movemt wide enough to enable proper dinsengagement of the pressers restraint; perhaps there is something hindering this... I hope you can fix it and ledt us know/keep posted.

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