J.A. Michell Prisma restoration

AngrySailor

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The finger lift is broken off of the SME headshell... I found a replacement headshell but didn’t like the £296 price tag... found these guys on crapazon which will mount to the cartridge bolts... figured worth a shot. Also ordered an anti skate test record for final set up. Just another thing to add to the long list of jobs when I get home... DF378638-99B1-4FB3-8341-AA0A35263C84.png
 

62vauxhall

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The finger lift is broken off of the SME headshell... I found a replacement headshell but didn’t like the £296 price tag... found these guys on crapazon which will mount to the cartridge bolts... figured worth a shot. Also ordered an anti skate test record for final set up. Just another thing to add to the long list of jobs when I get home... View attachment 42824
For what you get, that's expensive. Last year I ordered one of same for an SME headshell. It seemed like dozens of Chinese vendors (or the same one dozens of times) were offering those on E-bay for two or three bucks and same for shipping.

I've still yet to install mine - still in the plastic bag.

Granted, I'm in BC and took about a month to get. I could not bring myself to spend more than what I did for a small piece of metal like that. It only cost pennies to make in the first place.

The one I got goes underneath the headshell therefore the V bend. The picture you posted looks like it goes on the top. That works and I have an SME headshell where a finger lift from a Hitachi (or something) headshell was installed that way. Doesn't look too strange.

IMG_4546.JPG
IMG_4548.JPG
 

J!m

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I'm planning to buy a bunch of the top mount ones.

I like the shorter length to reduce resonance as well as weight.

I'll probably dip the end in "tool dip" to deaden it and make it "fancy"...
 

AngrySailor

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For what you get, that's expensive. Last year I ordered one of same for an SME headshell. It seemed like dozens of Chinese vendors (or the same one dozens of times) were offering those on E-bay for two or three bucks and same for shipping.

I've still yet to install mine - still in the plastic bag.

Granted, I'm in BC and took about a month to get. I could not bring myself to spend more than what I did for a small piece of metal like that. It only cost pennies to make in the first place.

The one I got goes underneath the headshell therefore the V bend. The picture you posted looks like it goes on the top. That works and I have an SME headshell where a finger lift from a Hitachi (or something) headshell was installed that way. Doesn't look too strange.

View attachment 42825
View attachment 42827
Yeah they’re not worth $20 for sure but I didn’t see any on eBay any cheaper. Also by the time I get around to making one I’ll have forgotten about the $20! Any I saw on eBay were $30US for one. If I wins sure it would fit, I might have gone with the under mount. As it is the over mount doesn’t cover the SME logo and I’m wondering about the cartridge to headshell contact with that between them also???
 

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Someone on this forum should have access to a water jet cutter and some aluminum stock, say .0625" (1/16") and then we could all have one for a few pennies.
 

AngrySailor

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Someone on this forum should have access to a water jet cutter and some aluminum stock, say .0625" (1/16") and then we could all have one for a few pennies.
Now you’re talking. Being aluminum it would be simple enough to make a set of dies to bend them to shape consistently. Something you smack with a hammer or attach them to a pair of snips or vide grips...
 

J!m

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I have a good water jet source but he’s booked out five weeks currently.

Could make them from shim stock as thin as you like.

Someone send me a print and I’ll get a quote.

I’m still finishing up my tonearm drawings or I’d draw it up. Maybe next week I could draw it. I think I’ll use stainless shim stock. Light in a small size and reasonably strong.
 

mlucitt

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Jim,
Could we use a SME or Pioneer finger lift as a model and maybe a CAD machine could do the measuring (an exact copy)? I like 7075 aluminum alloy for strength (almost as strong as steel in the same thickness), lighter weight, and nonmagnetic. I can get a 12" x 12" sheet of .063" 7075 for $21.55. We could make 288 finger lifts (2" x 1/4") from that piece.
https://www.onlinemetals.com/en/buy/aluminum/0-063-aluminum-sheet-7075-t6/pid/12659
If the water jet cutting costs $100, and the material costs $30, shipped; each lift would cost $0.45. I'd bend them for free. If we sold them for $50.00 each, we could advertise them as having more "air" and "bringing the front of the music to the listener", or even "expanding the stereo soundstage" like all the other audiophile products...
 

J!m

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Not sure how well 7075 cold forms...

Water jet guy can supply material. So once i have a drawing I’ll get a quote. The more that are made the less they cost per piece. Could stack several types of shim stock and cut them all in one go...
 

J!m

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More good news I forgot about: he’s out 8-10 weeks as of Friday.

BUT sometimes he can squeeze in small jobs between the big ones...
 

AngrySailor

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Picked up one of these blank discs to set up my anti-skate. Seemed to be way out as the tone arm would drift when you dropped it. It didn’t take much adjustment to fix it. Very sensitive adjustment but the blank disc was the cats ass. 9BDE41F5-B000-406E-B1B1-95198EAD56D0.jpeg
 

J!m

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Those get you in the ball oark but stylus in a modulated groove is different than a blank disc.

Observe the cantilever from the front while it plays and fine tune it such that the cantilever stays straight, and not favoring one side or the other.

I used the Rega glass platter for set up and then fine tune by eye. Currently set at zero...
 

AngrySailor

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Those get you in the ball oark but stylus in a modulated groove is different than a blank disc.

Observe the cantilever from the front while it plays and fine tune it such that the cantilever stays straight, and not favoring one side or the other.

I used the Rega glass platter for set up and then fine tune by eye. Currently set at zero...
I can hardly see the cantilever even with my glasses on...:oops: need some lab magnifiers for that
 

mabrow

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Figured I’d post this in the turntable section... If you’re new to this project, I am working on (I believe) an early Prisma. I bought it from my Uncle and it was working aside from needing a belt and stylus, (possibly the stobe needs work?) however for some reason he removed the lid and replaced the original legs with rubber feet.

I am in the process of having a plastics fabricator make a reproduction cover for me and I plan to fabricate reproduction legs. Attatched are some factory drawings I’ve come across but I wondered if anyone here has a Prisma that they would post some photos of and maybe even some measurements?

I am after the details of the leg mounting arrangement and how the thumb screw leveling is fabricated. Also details of the prop rod and hole location as I plan to machine a replica.

I am away at work so for now I am gathering information and details required to proceed with the lid reproduction but also wondered if someone can identify the tone arm? I know it’s SME, but what model/series? The cartridge is Shure V15 type IV, I have a spare Shure stylus but am told it was dropped and bent :/ so I ordered a new replacement from Jico. Did I make a mistake there or are their products reasonable quality?

Thanks guys!
Hello AS,

I'm a newbie to this site. I was internet researching the Michell Prisma turntable that followed me home last week and found your post. See attached pictures.
This will be a new project for me (like I need another one!) and I was hoping to pick your brain on it. I'm 71 and just getting back into vintage audio.

I noticed your mention of sourcing a new dust cover and wondered how you made out? The cover on mine is cracked. Also wondered if you found any good sources for parts as mine will need some.

Have you contacted Michell support/service and if so were they helpful?

All for now and thanks,
Dennis
 

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AngrySailor

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Hello and welcome. Nice score! Yes I did have a new dust cover made by Hank at P&A plastics in Hamilton Ontario, Canada. https://paplastics.com/

He did a very nice job of it. I’m quite happy with it. Michel was receptive to making a replacement cover also however the UK is a long ways from me and I can only imagine what they would charge. They were helpful with information and small parts. Belts are readily available and the same across most of their turn tables. I think the belt was $30?

let me know if I can be of any help.
 

mabrow

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Hello and welcome. Nice score! Yes I did have a new dust cover made by Hank at P&A plastics in Hamilton Ontario, Canada. https://paplastics.com/

He did a very nice job of it. I’m quite happy with it. Michel was receptive to making a replacement cover also however the UK is a long ways from me and I can only imagine what they would charge. They were helpful with information and small parts. Belts are readily available and the same across most of their turn tables. I think the belt was $30?

let me know if I can be of any help.

Thanks AS I appreciate your reply. This will be a slow process I'm sure trying to source parts, if available etc. If I can be of any assistance to you with your table, let me know.
Is yours up and running now?

Thanks,
Dennis
 

AngrySailor

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Thanks AS I appreciate your reply. This will be a slow process I'm sure trying to source parts, if available etc. If I can be of any assistance to you with your table, let me know.
Is yours up and running now?

Thanks,
Dennis
Yes, mine is in use now and working flawlessly. I still haven’t reproduced original style legs but it’s otherwise complete. What parts are you missing? Yours looks very complete by your photos but then again I’m on my phone and can’t blow them up real big... looks like your sweep brush is even intact, I had to source a horse to repair mine!
 
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