Film-Tech Forum ARCHIVE: 16mm amplifier static

This is topic 16mm amplifier static in forum Film Handlers' Forum at Film-Tech Forum ARCHIVE.

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Posted by Damien Taylor (Member # 4255) on 04-06-2008, 05:31 AM:

Yesterday I turned on my Ampro Stylist Major, only to have the speaker put out nothing but static, not even a little bit of film sound came through. I looked inside and i'm pretty sure all the tubes were lit, although apparently this just means the heaters are working.

Does anyone know the fix for this problem, I'm really hoping its something easy like some 50 cent capacitors or something, i'm a sucker for the stylists retro good looks and I dont want to replace her just yet.

Any help would be greatly appreciated!

Posted by Steve Guttag (Member # 268) on 04-06-2008, 08:08 AM:

You really need to get the tubes checked with a genuine tube checker. Odds are, that will correct your problem once a proper replacement tube(s) are installed. However, as you suspected, there are other components that can indeed fail, like capacitors...especially the older ones that can dry out.

Steve

Posted by Jim Cassedy (Member # 4115) on 04-06-2008, 10:43 AM:

I love the Ampro's. Especially the various Stylist models!

Great retro-look, built like a tank and weighs about the same. [Big Grin]

I agree with previous post in that the 1st thing you need to do is locate some place, or some one, with a working tube tester.
(I think I'm one of the few people in San Francisco who still knows where to find one in this city!)

Questions:
>Is the exciter lamp lit?

>Does the static happen regardless of if the motor is on or off?

>If you have an old microphone with the proper plug, try connecting it seeing if it works.

>Try removing the photo-electric tube and see if the static goes away.
(Caution: old photo-tubes are 'fragile' and repacements are almost impossible to find. Do this in a semi-darkened room, the darker the better, with no sunlight and no flourescent lights. Bright sun and flourescent lighting can de-sensitize these old tubes)

Getting answers to these questions could help you or someone here better diagnose your problem.

The scan of the amplifier schematic I'm looking at is pretty bad. I assume that execpt for the power transformers and maximum capacitor voltage ratings ( due to the difference in US and Australian power) your amp is basically the same design as the diagram I'm looking at.

Posted by Damien Taylor (Member # 4255) on 04-06-2008, 11:20 AM:

It's a Stylist Major Mk II, the exciter lights fine, and the static occurs when the motor is off. I haven't checked the solar cell yet but I'll give it a try. I'm not quite sure what voltage I'm on since I run the projector through some rectifier looking box it came with, I never bothered asking what it was.

Posted by Bruce McGee (Member # 131) on 04-07-2008, 06:00 PM:

My first 16mm projector was a Stylist. Nice little machine.

The photocell is available for your Stylist: www.tubesandmore.com has them. Look on the cell itself and you will find the type that it is.

Check the smaller tubes on a checker first. The 3 tall ones are for the exciter, and push-pull output. I believe they are 35C5's.

Possibly, the tube sockets have corroded a bit. Try rocking the tubes in their sockets and see if the noise goes away.

How long since you last ran this Ampro?