FAIRCHILD 541A-312 CUTTER HEAD

[Alfred]

Hello everyone, I am Alfred form Barcelona (Spain) and new at the forum ...
I've been looking for some post about the cutter head FAIRCHILD but I can not find anything to talk about the problem I have ...
A few weeks ago I bought the model 541A-312 because I wanted more quality in the recording and leave my old Astatic magnetic head.
The situation is the following. FAIRCHILD gives me 4.2 ohms and plugged to the amplifier the sound is fine, but I do not feel vibration in the needle as if I feel with the astatic. So I think if there is no vibration in the needle will not be able to cut the disc.
Someone would kindly explain me what happens to the cuter head ?. It is broken somewhere inside? What I can do ?.
Thanks for the answer that you can give me.
Alfred

[Soulbear]

Hi Alfred,
If this works I'll be amazed but I'll try to post some specifications for you to look at, and maybe they will be of help to you.

Fairchild541-1.pdf

I Hope this in some small way helps, Regards Soulbear

[EmAtChapterV]

Is the armature centered between the polepieces? What condition are the damping cylinders in? Is the coil bobbin properly secured and not moving around on its own? If any of those are out of adjustment, the armature won't move well or at all.

Once you do get the armature free and moving, you'll be able to cut ridiculous recording levels, but nothing whatsoever above 8.5 kHz. Believe me, I tried. Get used to cutting at two-thirds or half-speed if you want any sort of fidelity.

[Alfred]

Hi Alfred,
If this works I'll be amazed but I'll try to post some specifications for you to look at, and maybe they will be of help to you.

Fairchild541-1.pdf

I Hope this in some small way helps, Regards Soulbear

Hi,
many thanks for this info you sent me...I will study carefully..

Regards

[Alfred]

Is the armature centered between the polepieces? What condition are the damping cylinders in? Is the coil bobbin properly secured and not moving around on its own? If any of those are out of adjustment, the armature won't move well or at all.

Once you do get the armature free and moving, you'll be able to cut ridiculous recording levels, but nothing whatsoever above 8.5 kHz. Believe me, I tried. Get used to cutting at two-thirds or half-speed if you want any sort of fidelity.

Hi,

many thanks for your reply.
I understand that I will not have the quality of an original recording, but I think I can get better results than with the old Astatic
I've checked all points you informed an all seems all right. I have some question about it. I see there is insufficient gap for movement the armadure
Also is fastaned by a holder with screws....and this makes it impossible to have movement.. It may be that this is so?
If you are not inconvenient, I attched photos of the cutter head. Your feedback are welcom for me

[Alfred]

Is the armature centered between the polepieces? What condition are the damping cylinders in? Is the coil bobbin properly secured and not moving around on its own? If any of those are out of adjustment, the armature won't move well or at all.

Once you do get the armature free and moving, you'll be able to cut ridiculous recording levels, but nothing whatsoever above 8.5 kHz. Believe me, I tried. Get used to cutting at two-thirds or half-speed if you want any sort of fidelity.

Hi,

many thanks for your reply.
I understand that I will not have the quality of an original recording, but I think I can get better results than with the old Astatic
I've checked all points you informed an all seems all right. I have some question about it. I see there is insufficient gap for movement the armadure
Also is fastaned by a holder with screws....and this makes it impossible to have movement.. It may be that this is so?
and if it is all right.
I read that this cutter head works with 500 ohm impedance..¡¡¡¡¡¡, when in my tester gives me 4.2 ...I do not understand anything..it has something for no to feel vibration in the needle ?. And if it turns out that's how works FAIRCHILD normally
If you are not inconvenient, I attched photos of the cutter head. Your feedback are welcom for me
Alfred

[Soulbear]

Hi Alfred,
Looking at your uploaded photos, it looks very much like Em hit the nail on the head with the Armature/Stylus Holder adjustment tips. It certainly looks like there is no space between the pole faces that the Armature could freely move into. Check out the photos and video on my "There Once was an Ugly Duckling" thread and you will see that initially I had the opposite problem. The gap between the pole faces and armature on my head was excessive, and this resulted in the armature not being centred and sticking to one or the other pole faces when no Audio was being fed to the head. When audio was fed to the head, because of the excessive gap, the armature would then clatter or chatter. My remedy, though not yet proven by actual disc-cutting, was to improvise reducing and DECREASING the gap by closing up the very limited spring plate adjustment and fitting square rubber which also helped to centre the armature. I think your solution may be by INCREASING the gap, giving the armature freedom of movement, whilst still ensuring that the armature remains centred. It's fiddly, tricky, perplexing, but keep at it and I'm sure that eventually you'll find the "Sweet Spot" on your Cutterhead. Regards Soulbear

[Soulbear]

Hi Alfred,
I forgot mention it in the above, but a good read of section III (3) in the Fairchild PDF I posted should get you on your way. Soulbear

[Alfred]

Hi Alfred,
I forgot mention it in the above, but a good read of section III (3) in the Fairchild PDF I posted should get you on your way. Soulbear

Hi Soulbear,
I have disassembled the head and no way to give it more space. The magnets have such force that kept the armature completely fixed. Is stiff...
Really I do not know how to gap more. ...I do not know how to do it......
Also as you can see armature is caught with a holder and four screws. I do not understand how this cutter head could really have movement at the exit of factory.
I think your situation was more easy to solve than mine. I have not range to act. You are knowledgeable, Do you have any idea more?

Regards, Alfred

[Soulbear]

Hi Alfred,
I do not own a Fairchild Cutterhead, although twice in recent times I appear to have been the underbidder at auction. I searched out the information on the Fairchild 541 in anticipation of becoming an owner only to miss out on the purchase of the same. I am aiming in the dark here, and if any 541 owners want to step in to correct me, and put me wise, it would be appreciated. If i've read the literature correctly it seems that the Armature is centred by loosening the locknut marked as number 4 on the illustration in the PDF file I've posted, then turning the adjustment screw marked as number 3. Usually to loosen one would need to turn the locknut and adjustment screw in an anti-clockwise direction. I read an article somewhere about somebody having the same difficulty as your goodself in making adjustments to the armature. I think the upshot of the article was that it was fairly easy to close up the gap by means of the aforementioned adjusters, but it was the Devils Own Work trying to open up the gap again, once the adjuster had pushed forward the dampening/centering rubber "Slug" that fills the Tubes to which the adjusters are fixed. It may be the case that this centering adjustment has been overdone by a previous owner, and/or that with age that this rubber has somehow fused itself to the tube, making adjusment impossible. If that is the case you may have to think of finding a method to press/drill/burn it out/ remove it. Then replacing this centering/dampening with the correct diameter Nitrile/Silicone/Rubber as used for industrial seals etc, and which should not prove too difficult to obtain, though if it was me doing this, I think I would obtain the replacement rubber first. I think that would not be far off what may need to be done, but hopefully other Fairchild 541 owners may step in and offer an easier, or more elegant solution. Regards Soulbear

[EmAtChapterV]

What I used to do to adjust the armature on mine: first back off and remove the rubber damping slugs and their holder entirely. Then unscrew and remove the magnet. With the magnet removed, you'll find two screws through the top of each polepiece - one holds the polepiece to the body, the other allows it to be adjusted. Loosen them both slightly, and place two or three pieces of regular printer paper between them and the armature. Then, squeezing both polepieces against the armature with the paper in between, tighten all the polepiece adjusting screws back down. Then remove the pieces of paper one at a time. The armature should be centered between the gaps left. Reattach and fasten the magnet, and the armature will stick to one side or the other. Reattach and fasten the damping slugs, then adjust them so the armature is centered between the gap again.

Three pieces of paper between the gaps gives enough space for cuts as ridiculous as these. Resonance and frequency response always left something to be desired, though.

[Alfred]

What I used to do to adjust the armature on mine: first back off and remove the rubber damping slugs and their holder entirely. Then unscrew and remove the magnet. With the magnet removed, you'll find two screws through the top of each polepiece - one holds the polepiece to the body, the other allows it to be adjusted. Loosen them both slightly, and place two or three pieces of regular printer paper between them and the armature. Then, squeezing both polepieces against the armature with the paper in between, tighten all the polepiece adjusting screws back down. Then remove the pieces of paper one at a time. The armature should be centered between the gaps left. Reattach and fasten the magnet, and the armature will stick to one side or the other. Reattach and fasten the damping slugs, then adjust them so the armature is centered between the gap again.

Three pieces of paper between the gaps gives enough space for cuts as ridiculous as these. Resonance and frequency response always left something to be desired, though.

Hello, I tried to put the paper between the armature and the pole pieces and the truth I've gotten some gap. I have plugged into the amplifier and finally moves. But I have two problems, the gap closes again slowly and the armature is fixed and more worrying yet, the cutter head heats up and smells like burnt ..... ..
Moreover.....what / where is the rubber damping slugs?. I do not find anything rubber in my cutter head...Is there a littel metal platen with four screws?.

Thanks for your feedback.
Alfred

[Alfred]

What I used to do to adjust the armature on mine: first back off and remove the rubber damping slugs and their holder entirely. Then unscrew and remove the magnet. With the magnet removed, you'll find two screws through the top of each polepiece - one holds the polepiece to the body, the other allows it to be adjusted. Loosen them both slightly, and place two or three pieces of regular printer paper between them and the armature. Then, squeezing both polepieces against the armature with the paper in between, tighten all the polepiece adjusting screws back down. Then remove the pieces of paper one at a time. The armature should be centered between the gaps left. Reattach and fasten the magnet, and the armature will stick to one side or the other. Reattach and fasten the damping slugs, then adjust them so the armature is centered between the gap again.

Three pieces of paper between the gaps gives enough space for cuts as ridiculous as these. Resonance and frequency response always left something to be desired, though.

Hello, I tried to put the paper between the armature and the pole pieces and the truth I've gotten some gap. I have plugged into the amplifier and finally moves. But I have two problems, the gap closes again slowly and the armature is fixed and more worrying yet, the cutter head heats up and smells like burnt ..... ..
Moreover.....what / where is the rubber damping slugs?. I do not find anything rubber in my cutter head...Is there a littel metal platen with four screws?.

Thanks for your feedback.
Alfred

Certainly I thought it might downgrade one millimeter on each pole piece to more gap. That could be a good option?

[Soulbear]

Hi Alfred,
I wouldn't start removing any metal from the pole pieces that you have dismantled. Can you remount the pole pieces but insert the spacing paper as Em has advised, re-tighten the pole piece mounting screws with the paper spacers in-situ, once re-tightened then remove the paper? I know it's a little oxymoronic but the pole piece mounting screws should be Loose/Tight-Tight/Loose if you understand? I've also included here, a little illustration of the damping. The tube at the base of the cutter is what I was refering to. On the ends of the tube Highlighted (1) you will see the locknut and adjusting screw, these need to be loosened anti-clockwise. When you have set the gaps between the pole faces and armature as per Em's instructions, you can begin the process of centering the armature.

Fairchild 541A Cutterhead Damping.jpg

The rubber "Slugs" Highlighted (2) are adjusted with the screws (1) onto the Armature/Stylus Holder by first turning the adjustment screw to the optimum position, so that, there remains a suitable length of travel of the Armature/Stylus Holder, then retighten the locknut. If my experience with "Ugly Duckling" is anything to go by, it may take you many, many, many, many!!!Attempts before you get it just so. Regards and Happy Cutting Soulbear

[Alfred]

Hi Alfred,
I wouldn't start removing any metal from the pole pieces that you have dismantled. Can you remount the pole pieces but insert the spacing paper as Em has advised, re-tighten the pole piece mounting screws with the paper spacers in-situ, once re-tightened then remove the paper? I know it's a little oxymoronic but the pole piece mounting screws should be Loose/Tight-Tight/Loose if you understand? I've also included here, a little illustration of the damping. The tube at the base of the cutter is what I was refering to. On the ends of the tube Highlighted (1) you will see the locknut and adjusting screw, these need to be loosened anti-clockwise. When you have set the gaps between the pole faces and armature as per Em's instructions, you can begin the process of centering the armature.

Fairchild 541A Cutterhead Damping.jpg

The rubber "Slugs" Highlighted (2) are adjusted with the screws (1) onto the Armature/Stylus Holder by first turning the adjustment screw to the optimum position, so that, there remains a suitable length of travel of the Armature/Stylus Holder, then retighten the locknut. If my experience with "Ugly Duckling" is anything to go by, it may take you many, many, many, many!!!Attempts before you get it just so. Regards and Happy Cutting Soulbear

Hi Soulbear,

I followed one by one the guidelines you mentioned me.....and I've got it ¡¡¡¡¡ ......My FAIRCHILD it works correctly¡¡¡¡
Problem it was I am obsessed that the operation of FAIRCHILD would be like my Astatic...., when it comes to working with the amplifier I see that is not so.
It was really unadjusted the armature and so the needle is not moving..... and by default the coil and the magnet is heated because it was always in contact with the the armature polo pieces ..
Now I only need to try it with a lathe that I still can not get it ..
You are a good knowledge on the subject, you've helped me a lot...

Greetings from Barcelona..Alfred

[Soulbear]

Hi Alfred,
I'm glad that it worked out for you, my input was intuitive, rather than being based on ownership and experience of a Fairchild CutterHead, although as I've previously said, I really would have liked to own a Fairchild but I ain't gonna be payin' Silly Bollocks Prices to become an owner. In truth it was really down to the wonderful insight and great input from Em that you've managed to nail it down, and it's to her you should be offering thanks as my input was minimal. I just think it's great that we can bring our problems to a forum such as this, and get help from other wiser and more experienced Trolls. I myself have recently benefited greatly from input by Markrob and Kiss The Groove. The posts by Bryan, Todd, Aussie, Mossy and many other contributors, only further helps to develop our understanding of this mutual area of interest. Now start makin those Grooves and Happy Cutting Soulbear

[Alfred]

Hi Alfred,
I'm glad that it worked out for you, my input was intuitive, rather than being based on ownership and experience of a Fairchild CutterHead, although as I've previously said, I really would have liked to own a Fairchild but I ain't gonna be payin' Silly Bollocks Prices to become an owner. In truth it was really down to the wonderful insight and great input from Em that you've managed to nail it down, and it's to her you should be offering thanks as my input was minimal. I just think it's great that we can bring our problems to a forum such as this, and get help from other wiser and more experienced Trolls. I myself have recently benefited greatly from input by Markrob and Kiss The Groove. The posts by Bryan, Todd, Aussie, Mossy and many other contributors, only further helps to develop our understanding of this mutual area of interest. Now start makin those Grooves and Happy Cutting Soulbear

Hello..
of course ¡¡¡ thank you very much to EM that their contribution was providential to obtain this happy ending ¡¡¡