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Manticore Mantra repairs

cj66

cj66

pfm Member
Following in from digging out my Mantra, sorting the wiring on the arm and then finding it plays a little slow, with a "ticking" from the motor.

New belt has not arrived yet but I've checked the cap n resistor for controlling the motor and found the resistor to be charred.

My best guess from the bands is a 2kohm 1w? jobby required and probably worth changing the cap while there.

Does anyone know the ratings for these? My googling didn't help.
I was also surprised to see the motor marked as 110v. This has run happily on 230v.

20220819-015954.jpg


20220819-015737.jpg
 
here are the "instructions" for the motor.

https://www.farnell.com/datasheets/1685512.pdf

Now branded premotec but it's the exact same one.

It's unlikely to be of any benefit to change either of the components on that board. The speed of the motor is down to mains frequency so it won't make any difference to that and they look to be in OK condition.
 
It hasn't blown or the TT wouldn't work. Unlikely be the cause of the above issues.
I have a Mantra as it happens.... haven't used it for years...
 
I was vey tempted to buy one but I saved up a bit more and bought the Linn.

At the time Doug was demonstrating it with a Linn Basik plus arm and hadn't yet seen the light of putting the Rega arm on it.
 
colasblue said:
I was vey tempted to buy one but I saved up a bit more and bought the Linn.

At the time Doug was demonstrating it with a Linn Basik plus arm and hadn't yet seen the light of putting the Rega arm on it.
Click to expand...

It being basically only usable with Linn arms is one of the reasons I stopped using it actually.
 
The ticking might just be down to the fitted thrust bearing cap on bottom of the motor. Suggest pulling this off and cleaning it out followed by applying a bit of grease. These are not an original Philips part; some are just an interference fit, others glued on, not sure about the Manticore.

BTW, most all UK TTs with AC sync motors historically employed a 110V motor (Rega has gone over to 24VAC across the board nowadays). It is the burnt resistor that drops the circa 220 - 240V down to (usually) less than 100V (for best noise performance), hence the heat. Rega, for example, started out using 15kOhm here then dropped these down to 12kOhm UK, 10kOhm Europe (before going over to using a second 0.22uF cap as voltage 'filter' in place of the resistor). If replacing this, look for a metal oxide type with a higher heat tolerance.

P.S. The phase cap is 0.22uF, same as originally specified by Philips (in fact, it looks like it might be a Philips).
 
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That thrust bearing cap looks like a ferrite ring with a brass insert, which in turn ( not visible in my pic ) has a screw within it. Not noticed that before.

After seeing the motor spec. sheet I had deduced the resistor was only there to drop the voltage. Thanks for the extra info though.

I also realised the pulley could be removed without much resistance. I have added a tiny sliver of very fine material into the pulleys spindle hole and refitted it, now it grips the motor spindle properly.
Added a drop of oil from the pulley end and worked that in.
Pretty late here so will continue tomorrow...
 
The motor is sounding far more healthy today. I can only hear it with my ear right up close to it.
I've ordered the new resistor and cap, to be on the safe side, and will test it again after the new belt arrives.
 
cj66 said:
That thrust bearing cap looks like a ferrite ring with a brass insert, which in turn ( not visible in my pic ) has a screw within it. Not noticed that before.
Click to expand...
Interesting. There are not many Mantra motor pics about, however, it appears that Doug Hewett may have been a pioneer in adjustable turntable motor thrust bearings. This one looks as though it could be Nylon (or, perhaps, Delrin) with a threaded brass insert within...

16-896299c5.jpg
 
On a closer look, yes it could be plastic of some sort. I also agree that it must be an adjustable thrust bearing.

20220820-005037.jpg
 
A 10k resistor will be dissipating almost 2W here, I would use a 5W. My STD 305 had a resistor using one of those gold finned packages
 
Whilst waiting for the "bits" to arrive, the next thought is an inexpensive cartridge. Just to get decent quality sound for my remaining records, I'm not going to be buying any more ( he says ).
First thought is the much lauded AT-VM95ml to work with my XLPS.

Screenshot-20220821-202338-Xodo-Docs.jpg


My usual preference is MC ( F5stilton, OC9mlii, Lyra Lydian ) but open to suggestions below £200.

davidsrsb said:
A 10k resistor will be dissipating almost 2W here, I would use a 5W. My STD 305 had a resistor using one of those gold finned packages
Click to expand...

That was my initial thought as well, then I considered how long that 2.5w basic R had been there, charred but not dead. I've ordered a 3w metal oxide.

Craig B said:
Doh! Too many cartridge loading posts yesterday, David. Now corrected.
Click to expand...

Too easily done but the link had the correct value anyway :)
 
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