J.A. Michell Prisma restoration

[mabrow]

Source a horse..LOL. Figure this will be a drawn out refurb. Not really in a hurry though I would sure like to hear it.

Sweep brush is there but missing the underside locking mechanism. Tonearm main shaft, guess that's what it's called is loosely goosey like parts are missing inside there, power cord has been cut and patched. Tried plugging it in but unit is not turning on...what did I get myself into!!

If you want, I can send you the leg set so you can get duplicates made. Just pay for shipping back and forth. Up to you.

Out of here. Reforming a speaker.

Dennis

 

[mabrow]

Oh, just in case you didn’t see it back in the thread, are you aware of where the coarse speed adjustment pot is? You must remove the switch cover and expose the motor top, there is a small hole through the top of the motor case (maybe 3/16” hole”. Insert a 1/8” slot blade screw driver very carefully until you engage the potentiometer. I made this adjustment with my fine pots set in the middle and have had no issues since. (Mine was running slow).

Have to get the power cord replaced 1st to see if the motor even works.
Thanks!

 

[AngrySailor]

Source a horse..LOL. Figure this will be a drawn out refurb. Not really in a hurry though I would sure like to hear it.

Sweep brush is there but missing the underside locking mechanism. Tonearm main shaft, guess that's what it's called is loosely goosey like parts are missing inside there, power cord has been cut and patched. Tried plugging it in but unit is not turning on...what did I get myself into!!

If you want, I can send you the leg set so you can get duplicates made. Just pay for shipping back and forth. Up to you.

Out of here. Reforming a speaker.

Dennis

Thank you for the offer of the legs for a pattern but I think with the Michel drawings I have and maybe some good pictures of yours we can probably get by without shipping parts around...

the power switch is a magnetic actuated reed switch. Once you get your power cord replaced check the switch is working. Good luck!

 

[mabrow]

Ok and thanks again!

 

[mabrow]

Hi AS,
Been awhile since we've conversed. I have slowly been going through this TT to try and see what all is there, what may be missing etc. I had a local plastics shop make a new dust cover since the original was cracked and they did a very nice job.

I've tried emailing Michell in England on several occasions. They finally replied to my 1st email saying "hey, we are real busy here" but offered no help. The other emails to them have been ignored, so basically they are saying F off.

Have you been in contact with other Prisma owners while going through your refurb? If so, kindly let me know their contact info. The tonearm on mine is puzzling and I've not found a thing on it to see how it is assembled. Apparently something is missing as the lower and upper main body of it aren't solidly joined together.

I've attached pictures of the arm and the last picture shows the separation from the upper/lower assembly. It really just flops around. Perhaps someone else has experience with this arm and can provide some guidance.

Thanks much,
Dennis

 

[AngrySailor]

Hi AS,
Been awhile since we've conversed. I have slowly been going through this TT to try and see what all is there, what may be missing etc. I had a local plastics shop make a new dust cover since the original was cracked and they did a very nice job.

I've tried emailing Michell in England on several occasions. They finally replied to my 1st email saying "hey, we are real busy here" but offered no help. The other emails to them have been ignored, so basically they are saying F off.

Have you been in contact with other Prisma owners while going through your refurb? If so, kindly let me know their contact info. The tonearm on mine is puzzling and I've not found a thing on it to see how it is assembled. Apparently something is missing as the lower and upper main body of it aren't solidly joined together.

I've attached pictures of the arm and the last picture shows the separation from the upper/lower assembly. It really just flops around. Perhaps someone else has experience with this arm and can provide some guidance.

Thanks much,
Dennis

Hello Dennis, glad to hear you’re still working at it. I did get some helpful responses from michell but that was pre CoronAIDS. I think they basically shut down due to the ‘rona. I do not know any other Prisma owners and my tone arm is different than yours, however I do have the original prisma manual which might cover your tone arm. I can check later this evening when I get home.

 

[mabrow]

Thanks A.S.

I have a few manuals/diagrams that I've found here and there, however none of them cover the tonearm in detail. Hope what you have might be the proverbial missing link.
Dennis

 

[AngrySailor]

Thanks A.S.

I have a few manuals/diagrams that I've found here and there, however none of them cover the tonearm in detail. Hope what you have might be the proverbial missing link.
Dennis

I got roped into working late but I’ll see what’s in there and probably just post the whole thing. It will be late or tomorrow though.

 

[mabrow]

Appreciate it AS and don't work too hard.

 

[J!m]

I not know that tonearm specifically but it might be a single point, which are a bear to set up...

 

[mabrow]

Thanks Jim. As there were not many of this turntable models made, info is hard to come by.

 

[J!m]

What gets posted here may become the reference site for that arm when we're done...

 

[mabrow]

Could be. I'll keep digging around for info.

 

[AngrySailor]

Let me know if this is of any use and I can mess around more for better scans or pictures.

 

[AngrySailor]

And the last few pages.

 

[mabrow]

Thanks AS. I do have those pages. I did find additional instructions on the artech-electronics.com website and some info from a Florida gentleman selling Michell parts on eBay. Years ago this eBay seller bought many "new-old stock" parts directly from John Michell, however thru the years he has sold off just about everything he had.

I'll keep looking for tonearm info and also any info concerning the motor. Broken wires in/around the motor. Also just found that the motor circuit board is cracked, some cracked resistors. The more I dig into this, the more issues I find., and I'll need to source a capstan as the one for this table is AWOL.

Thanks again and take care,
Dennis

 

[AngrySailor]

Thanks AS. I do have those pages. I did find additional instructions on the artech-electronics.com website and some info from a Florida gentleman selling Michell parts on eBay. Years ago this eBay seller bought many "new-old stock" parts directly from John Michell, however thru the years he has sold off just about everything he had.

I'll keep looking for tonearm info and also any info concerning the motor. Broken wires in/around the motor. Also just found that the motor circuit board is cracked, some cracked resistors. The more I dig into this, the more issues I find., and I'll need to source a capstan as the one for this table is AWOL.

Thanks again and take care,
Dennis

Sorry that wasn’t of any help. I believe I have seen some of his ads for NOS parts also. There was a fella on Canuck audio mart a while back who listed/sold a Prisma which had a replacement (non original motor) but came with the original, not working motor. I reached out to him asking if the table sold and the new owner wasn’t interested in the motor, that I would be interested for parts. I never heard back but I may still have his email and might put me in touch with the new owner? Can you post some pictures of the motor damage? It may be repairable with some jumper wires depending where the crack is. I would guess it’s not cracked under the clamshells where the motor windings are? I would think if the windings are fine there not much else there... what do you mean by capstan? The spindle bearing? There’s another member here machining and fabricating parts for a custom table/tone arm, think it might be Jim?

 

[J!m]

I can make stuff from prints and/or reverse-engineer from old parts.

I did some of the bushings that go on the base of the PL face handles for someone here a while ago…

I interpret capstan as the drive pulley for the belt. It’s probably crowned to keep the belt in place, similar to how Micro does it.

 

[AngrySailor]

I can make stuff from prints and/or reverse-engineer from old parts.

I did some of the bushings that go on the base of the PL face handles for someone here a while ago…

I interpret capstan as the drive pulley for the belt. It’s probably crowned to keep the belt in place, similar to how Micro does it.

Round belt in groves pulley. Possibly means the strobe idler? You can eliminate the strobe with a shorter belt. Also it seams many parts are interchangeable between michell models. Parts might be available new still. The belts are all the same length also.

 

[Nibeling06]

Hi AngrySailor,

I have carefully read the story of your restoration: really interesting. Thank you for documenting the entire restoration process, it is very generous of you and instructive.

I have a Prisma too that I am in the process of refurbishing. I have a problem with the 45 rpm pots not working. I wonder how you removed the piece of white plastic. Is it just screwed on?

Thank you !