Aunt Em


AUNT EM'S PROBLEM PAGE

Aunt Em is here to try to provide answers to the questions that experts generally take for granted, leaving the

novice floundering because basic building blocks of understanding are missing. Aunt Em is always glad to be

corrected or to get extra info from smart Alecs.

 

More on the Vox, with an excursion into an Elf conversion to 9.5

Q. I was wondering if you might have a couple of answers relating to a VOX. While I have been playing with the Elf, I have a couple of complaints.....The focus seems extremely touchy and never really blows me away for a modern projector and I have heard that they are not the most forgiving on shrunken film, so I pulled out my VOX having finally solved my frequency issue by purchasing an equally expensive beast of a converter that weighs about 90 lbs. Basically I could carry the VOX or the converter but not both so it probably won't ever leave the house.....

1 - I just realized that when I bought it I got a speaker cord  that is severed on the end....My question is are the three  1) brown 2) blue 3) yellow/green  wires standard and if one was to try and attach a female 1/4 inch jack to the end what wires might be attached to what?
My thinking - which you may just laugh at - is to hook up a speaker jack kind of like found on most modern projectors so I can just plug in the speaker I usually use when watching films.....

2 - I am having an issue with the take up reel randomly stopping, which my assumption is just built up gunk inside not allowing the belt or belt pulley to spin appropriately....What do I need to remove first to safely remove that side plate that is covering the gears...It looks like I might have to remove the amp, the motor, and more and I just don't want to do anything that is going to come back and haunt me, since you know how limited my skills are...I know you have taken these apart often as there used to be pics with the side plate removed on your site.

Oh and I noticed there are two sets of gears controlled by a turning knob, does that mean you can run silent films on the VOX as well? I never really knew that.....Hmmmm...


A. I never cease to be amazed at the things you don’t know. The Vox was introduced first as the S, ie silent, with the amp made available later as an add-on when the sound version was introduced. Problem is, it’s a fixed 16fps for silents and as such a bit too slow.

You are right in thinking a lot of dismantling is needed to get inside to the take-up pulley. If you remove the motor, you risk damage to the wires where they enter the motor due to their great age, so I advise against.

Start with the belt itself. If it is too slack, or has stretched bits in it, or the join is long, all of these things can cause what you describe. Or if the belt is too oily.

If the take up pulley on the spool arm is stiff it can also cause problems – have you cleaned that up? Even a bent reel can cause trouble – if the width is reduced at one point it can be impossible to get a smooth take-up.

Now and only now can we consider the pulley inside the machine. There should be an internal guide which allows you to thread the belt thru and back out without problems. You could try a pipe-cleaner or even use a bit of spring belt to pull thru a narrow strip of cloth which you can hold at both ends and to and fro it to clean the pulley. However, I think your problem is much more likely to be outside.

Re Elf, it mite be that your focus problem is the lens. Short-throw lenses are notoriously difficult to get in focus all across the pic and are very easily de-focussed, and of course film focus can change too. Lenses with very low f numbers are the worst I suspect – summat to do with depth of field. You could experiment with a sleeve to hold an old B&H lens and find a slow one with a higher f. As for shrunken films, most 9.5 sound films should not yet be much shrunken, and if you are showing silents on the Elf you have left the path of wisdom. If you do not have a Specto, I can provide one.

Re speaker lead, I am not sure what you mean. What is it that is severed? Is it a lead emerging from the projector? A speaker lead for a transistor/solid state amp should have just two wires – it could be that Keith had used standard mains cable of live (brown), neutral (blue) and earth and only used two of the wires. You should have no problem doing what you suggest if, as I assume, your amp has been converted – valve amps are a bit more difficult. I use several B&H speakers permanently set up by the screen with the DIN-type speaker plugs and sockets for the cables, and all amps use one or other of these, with a short jack-to-DIN converter lead for the likes of the Elf. Basically, you just need to identify which two contacts inside the amp you need to connect to your jack socket.

Pl let us know how relevant this advice was to your needs by completing the following Customer Survey ………..

Q. First let me at least address the what I don't know part...I of course knew that the Vox came on the heels and design of the "S", but I just did not know they made it a 2-speed. I thought they simply changed the pulley and it was a single speed sound projector...Luckily I was able to deal with the belt without taking the machine apart. It definitely began seeming like the belt might be too loose, so I unhooked it and took it off, then cleaned the pulley inside and re-attached the belt but not before breaking off about half an inch. So far I have run a number of reels and it has not stopped since...

Now back to the amp......First off, how is the amp supposed to work? I am still puzzled by the whole twisty volume control (like the Home Talkie) I have yet to figure out on either machine if the amps are not working or I just don't know what I am doing....I tend to believe I am the problem, which I am sure you are on board with....... VOX specific.....I know when I open the amp cover there is some sort of crank switch that clicks and turns, but I have heard that you must have the speaker attached for the amp to even come on.....It feels like parts of it heat up, so my guess is it is on, but is it working? I never even hear speaker crackle, which causes me suspicion Perhaps if you could tell me how things are supposed to work, I might be able to see what "isn't"  and I will take some pictures of the 3 wire connection to see if you might spot an issue there........ Does anything need to plug into the pick up or is that just for some microphone thing....I have played with the optical light adjustment back and forth but never a sound, same thing with the volume twisty......................I like how gentle it seems on the film, and how even damaged film seem to pass through it without even losing a frame., but no sound...

As for the Elf, I have had better luck, and actually found an original Eiki 25mm lens that improves the focus considerably, now I need to find an original 38mm Eiki lens and I will be set.

PS.  Is the sound on 9.5 ever good? Everything I have just bounces between passable and almost unintelligible in the same reel.
 

A. Glad you got the take-up working – no need to thank me for the advice – oh, you didn’t.

1. Getting an original Vox amp working is far beyond my ken.

2. I have no idea what you mean by a crank switch.

3. The so-called volume control simply cuts off part of the light bounced from the sound telescope via the mirror. Less light = less sound. Trouble is it also affects the quality.

4. An original Vox amp was, I believe, wired so that the speaker plug incorporated a short across two pins which completed the circuit for the amp power supply – in effect an on-off switch. I am not sure, but it is quite possible that the valve heaters were on as soon as power was connected to the projector, but not the amp circuits themselves. And who knows what changes may have been made over the years? It’s no use trying to run the amp; it is almost certain that the output capacitors have long faded and you will do more harm by running the amp before these are sorted. But there is so much that can be wrong with a really old amp. There is incidentally some stuff on amps under care and repair on my website.

5. Pick-up is just for a non-synch record deck.

6. Re Elf focus, even with an original Elf lens there can be problems if the little rubber bit on the focus wheel shaft inside the lens barrel is perished – it could make the lens just a tad loose and so harder to keep in focus.

What I would strongly recommend is leaving the amp alone for now, and not plugging in the speaker. Fit a diode/cell in place of the mirror under the sound telescope, lead the wire away via the arm supporting the sound drum and plug it into the microphone input of a 16mm projector amp – I used to use an old-style B&H for this (now I use a transistor replacement designed for one of the same machines, but as a stand –alone). This way you get the full benefit of an amp and speaker specifically designed for cine. Non-cine amps will not give you the best results from 9.5 optical which can, at its best, rival 16mm.

There are many other things in the long chain of things involved in producing sound, eg the stability and smoothness of the sound drum in its rather basic bearings, the free-running of the roller that holds the film onto the drum (ensuring also the groove it runs in is clean), the cleanliness of the telescope optics and the width of its internal  slit, the exact position of the lamp (if you are not using original Vox lamps), the presence or absence of the little cover inside the lamphouse that stops extraneous light getting down onto the film and the cell/mirror and etc. A lot of this is in the piece on my website under 9.5 sound called In Search of the Lost Chord.

I am happy to field supplementaries, but pl remember that pix can help – I would especially like to see inside that amp cover.