Rega Planar 3 Upgrade(?) path

[derek92994]

AC motors are very accurate in speed, provided that the hertz from the supply is stable. I hear its difficult to change the speed of AC motors because it involves changing the hertz, requiring an expensive speed box. At least to my limited knowledge. Correct me if I'm wrong.
The Thorens TD 160 Super, 165 and Pioneer PL-31D tables I own are all AC motor and I had to resort to changing the size of the platter or motor pulley to slow them down, because they were all slightly fast. I'm told this was done to compensate in case the hertz coming from the power socket was slightly out. The increase in speed drove me nuts, as I am very pitch sensitive.
I can relate with having to remove the platter and manually move the belt onto the larger part of the pulley to change speeds, the Thorens tables are very stubborn if the belt is not 100%, they simply will not change speed if this is the case. Sometimes the belt will throw itself off if you try to start it from a dead stop at 45rpm speed, so a gentle turn of the platter will be required on startup.

 

[derek92994]

Nice work on the upgrade path by the way, it has been a good read.

 

[J!m]

The belt did not want to stay on 45 and kept walking down to 33 on mine. Sort of annoying when trying to copy a rare record to digital that is at 45 rpm and the speed changes mid song. It was amusing the first time; not after that…

And now my Kenwood thinks it’s a land based gas turbine and running as fast as it can. So, I have no vinyl action until further notice.

 

[derek92994]

And now my Kenwood thinks it’s a land based gas turbine and running as fast as it can. So, I have no vinyl action until further notice.

That is unfortunate, I would go stir crazy without a functional table, or maybe just listen to the digital rips done from the collection.

 

[J!m]

I’ve got plenty of CDs to listen to, and usually no time to listen anyway these days, so it’ll be in the car and in work on the boom box.

 

[J!m]

Found a nicer power switch. It’s like $50 however. I wanted metal and it has a blue LED indicator. I’ll have to work out dropping resistors but it’ll be classier than the plastic switch secured with duct tape.

 

[NeverSatisfied]

Jim if you polish the platter, are you going clear coat it or leave it raw?

 

[J!m]

I’ll probably polish the chamfer only, and scotchbrite the other surfaces while it spins in the lathe.

Finishing is a bit poor on this. The record surface is immaculate but the aluminum doughnut and the mating surface for the doughnut are rough. Just because it won’t normally be seen, is not a reason to slack off.

The OD is a bit rough too. Not as bad as the unseen areas. I’ll get it all sorted out and post after pictures.

 

[J!m]

Okay. Here we have the current state of the doughnut:


As you can see, this is not high-grade material. I suspect not heat treated, or not alloyed (6061)... Not sure, but it's very gummy and gets blotchy when worked. This will not be as easy as predicted (is it ever???).


This is where I conceded defeat. This turd was not taking any more polish!


After very thorough cleaning (acetone, then electrical cleaner), she's ready for clear coating.

I think there is enough difference between the polished chamfer and brushed top, bottom and OD to look good. (inspired by the vintage Pioneer knobs and Kenwood platter)

 

[NeverSatisfied]

I can see an improvement, polished turds still look better than unpolished turds.

 

[J!m]

The first photo I had already went through scotchbrite after polishing the chamfers. I switched to emery paper after that.

Stock was not polished anywhere and pretty grungy.

 

[J!m]

When I applied the clear, the orange peel sort of ruined my work, but I'm tired of turd polishing (I do it all day).

I may re-think the lighted switch. I am going to add a bullseye level to the top, because, why not? I thought I'd set it next to the power switch, in an aluminum bezel. Then I thought... hmmm... wouldn't it be trick if the power indicator LED also illuminated the level? So, that's where my troubled mind is at now.

What do we think?

I also picked up an (overpriced) piece of aluminum angle, to add connectors to the back. Rega runs the earth line along with one channel's shield, which I don't care for. And you're stuck with their cables (not that they're that bad). So, I am going to add a pair of mini XLR connectors, a ground binding post, and then make up cables (with Mogami Neglex quad) that terminate with an RCA. But, it will have the future "upgrade path" of running properly balanced from the 'table to the preamp, if I ever upgrade the preamp from the WP-1 (which is honestly not likely). But, it's supossed to be an "upgrade" right?

Back to searching for switches...

 

[J!m]

Important question (for those of you who actually know stuff):

Earth grounding and signal shield.

I think that I want to have the shield floating at one end, between the table output and the RCA input at the other end. Actually, it will have to float at the RCA end, so I guess that's answered... Should the shield at the table end be connected to A/C ground, or connected to the tonearm drain (and ground lug)?

The earth grounding: Should I combine the A/C ground with the tonearm earth line? I am considering a change to an IEC power input connection. Originally it's just a polarized two-wire cord. Maybe the A/C should be left out (no A/C earth) and the tone arm only connected to the ground lug? Maybe a ground from the main bearing well and tonearm to the ground lug? (static drain)?

What do we think is the best route to take? This is confusing, yet important... Signals are so low that minor changes can have an audible impact.

 

[J!m]

Just ordered connectors, the switch etc. to finish this up.

 

[NeverSatisfied]

When I applied the clear, the orange peel sort of ruined my work, but I'm tired of turd polishing (I do it all day).

I may re-think the lighted switch. I am going to add a bullseye level to the top, because, why not? I thought I'd set it next to the power switch, in an aluminum bezel. Then I thought... hmmm... wouldn't it be trick if the power indicator LED also illuminated the level? So, that's where my troubled mind is at now.

What do we think?

I also picked up an (overpriced) piece of aluminum angle, to add connectors to the back. Rega runs the earth line along with one channel's shield, which I don't care for. And you're stuck with their cables (not that they're that bad). So, I am going to add a pair of mini XLR connectors, a ground binding post, and then make up cables (with Mogami Neglex quad) that terminate with an RCA. But, it will have the future "upgrade path" of running properly balanced from the 'table to the preamp, if I ever upgrade the preamp from the WP-1 (which is honestly not likely). But, it's supossed to be an "upgrade" right?

Back to searching for switches...

On my platter I am wet sanding between clear coats, will probably end up with a least 3 coats to get a perfect deep finish.
I like the lighted bullseye idea, a little extra bling is always nice.
No idea about the grounding question, other than are you fixing a problem or just want the best theoretical connection?

 

[J!m]

I can’t find an 18mm ID ring terminal so I guess I’ll make one from brass shim stock. (Cuz I don’t need a 0 gage ground lead)

I think it’s better to ground the platter than keep it isolated. But, with a non conductive bearing ball and non conductive tip on the platter shaft, I’m not sure what good it’ll do.

 

[J!m]

Here's the switch and level bezel design:

 

[J!m]

I got the quote for the switch and level bezel, so we are moving forward with that.

I am also making up the connection interface for under the new plinth. I have a ground binding post as well as mini XLR jacks for the output. It will be true balanced at the jacks but dumbed down to typical single ended wiring by the cables I'm making up. But it will be easy to convert it to balanced down the road if I want to.

 

[J!m]

Tripped over this on the way out tonight:


Looks like it’s coming together!

But, (there’s always a but), the underside is raw Baltic birch. I could stain or paint it, maybe cover with some black plastic, but I’m thinking a plate of aluminum with beveled top edges would look trick. Muck more expensive than the aluminum “cheeks” idea however.

Veneer looks nice enough so no point covering the sides. A bottom plate could be directly threaded for the main bearing well, and also act as the motor cover. Great RF shield too but not good for EMI.

It would add a good bit of mass too, but that’s not always a good thing. New plinth seems heavier already (I’ll weigh them both tomorrow) and seems to decay quickly but is far from “dead”.

I’m going to set brass machine screw inserts for assembly rather than wood screws. I’ll probably keep the wood screws for the dust cover but it’s easy to upgrade to inserts later if I want to. Or I may just do it all now…

I don’t know if I mentioned it but I ordered one of those cheap arm lifters for the end of the side so it’s not grinding away on me.

The new switch is in hand so I can be sure everything fits correctly with the bezel.

I have a small rectifier (and some large ones too), but if I run AC direct to the LED won’t I get it flashing at 60 hz? I have the correct resistor worked out to drop from 120 to 2 but I thought I had heard that since it’s a diode it rectifies itself?

Oh, the mini XLR connectors are not going to be fun. I may order the slimmer quad cable because I can already hear my colorful metaphors without even having the cable in hand…

 

[NeverSatisfied]

Coming together nicely, it is going to be gorgeous.