pdcman wrote: ↑2023-03-21 15:03 With anything other and water and a cloth, time alone will tell of any damage done.....

It’s too bad it’s not cleanable like the pulley, Cleaning the pulley alone made a significant improvement. Cleaning the subplatter a few days later also made a significant improvement and I can’t recall when my drive system operated as well as it’s doing now. I suppose you would have to go back when all those components were brand new, which was 1986.

I’m not convinced I did anymore harm to the subchassis other than cleaning the debris that accumulated over the years.

This is not my subchassis but this shows a used Cirkus subchassis. I would assume the condition of this one is typical for a subchassis that’s been used for several years. I doubt water and a clean cloth is going to remove the belt grit that has accumulated over the years.



It baffles me that Linn would apply lacquer to a part of the drive system where keeping it clean is so important to the turntables performance. I’m also thinking that ThomasOK might be correct that the vertical surface in not lacquered though he did say to check with the Linn Helpline. I still question the Helpline response.

Given Linn Helpline's suggestion, would a dampened Mr Clean Magic Eraser be worth a try? I don't know if that's less or more aggressive on a lacquered surface... I can see how Brasso could be detrimental if used too often and with too much pressure, but I'd say it's a deficiency if that surface can't be cleaned effectively to maintain performance.

I went at the subplatter this morning with 17 more Q-tips and Brasso followed up with IPA to make sure I got any leftover Brasso residue. Here’s the result which I’m pretty satisfied with as far as cleanliness goes. It was much worse before I began the cleaning process last week. The subplatter looked more like the one in the photo above.



To be clear, it is the US version of Brasso that I’m using which I understand is a different formulation to meet US environmental regulations.

https://www.homedepot.com/p/Brasso-8-oz ... 42#overlay

tokenbrit wrote: ↑2023-03-22 14:15 Given Linn Helpline's suggestion, would a dampened Mr Clean Magic Eraser be worth a try? I don't know if that's less or more aggressive on a lacquered surface... I can see how Brasso could be detrimental if used too often and with too much pressure, but I'd say it's a deficiency if that surface can't be cleaned effectively to maintain performance.

The “black oil” bearing came out in 1987, the Cirkus in 1993. Those matching sub-platters are now as old as 36 years. The Linn owners manual makes no mention of doing any maintenance on sub-platter surface though I’m pretty certain after a period of time belt shed accumulates and adversely affects performance.

I have no doubt that part of the improvement heard from the upgrade to Cirkus or Karousel was due to the nice and new sub-platters provided with the bearing.

Here’s a LP12 startup video I made with the outer platter upside down. You can see how the belt drops down on the pulley at startup setting the suspension in motion. It takes a few moments for the suspension to settle down and the belt to align on the pulley and sub platter.

https://youtu.be/53bkqJP7tc4

John wrote: ↑2023-04-02 21:59 .. see how the belt drops down on the pulley at startup...

Interesting - I don't see as much suspension movement as I do vertical movement of the belt on the motor pulley... Or am I seeing it wrong :?
I wonder if the belt drops lower on the motor pulley, onto the smaller circumference, due to the startup torque... the smaller part of the pulley would have a very slightly better gear ratio to help spin the platter up to speed, wouldn't it?

tokenbrit wrote: ↑2023-04-02 22:46

John wrote: ↑2023-04-02 21:59 .. see how the belt drops down on the pulley at startup...

Interesting - I don't see as much suspension movement as I do vertical movement of the belt on the motor pulley... Or am I seeing it wrong :?

I focused on the pulley with the camera and seeing that movement is easier. The belt movement does set the suspension in motion which might be less obvious. You can see the platter movement if you focus on it on a larger screen than an iPhone.

I wonder if the belt drops lower on the motor pulley, onto the smaller circumference, due to the startup torque... the smaller part of the pulley would have a very slightly better gear ratio to help spin the platter up to speed, wouldn't it?

I think you’re right.