Rek-O-Kut Turntables - ROK

Article - Which ROK TT Shall I Buy?

See attachment for a discussion on the Rondine Deluxe, Rondine, Rondine Jrs.
Ah ha! This answers a question I was just about to ask. Does anyone know where the b-12GH fits into this hierarchy? And has anybody actually heard all of these decks and have an informed opinion about the relative quality of all three? I've heard some love for the Rondine Jr because you can mount the tonearm separately from the metal plinth, but I'm not totally sure how the motor factors into that equation.
Thanks
 
I would say the B12GH is probably the best of the bunch. I have a B-12H which has a bigger motor, but in this case it might be a bit too big to the point that it's a lot of vibration to handle. It's working out on my table but I suspect the Pabst motor of the GH is a little smoother and easier to deal with, and reports from those who have them seem to corroborate that.
 
Can anybody tell me the specs on this spring from the B12? Mine somehow got bent up over the years. It goes in the little well on the background picture to keep the arm coming off the motor assembly in contact with the speed selector gear (though it's not really a gear, it's the wavy part that the speed slector know attaches to.) It's labeled as part 50 on the exploded diagram earlier in the thread, but I don't have the specs to go with it. Of course, I could just go buy a bunch of springs and see what works, but I'd like to save time and money and just get the right thing the first time.
 

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Do you have the wooden spacer that goes in the rectangular well the spring goes in? It's #84 in the diagram. I think its purpose is to keep the spring from kinking that way. If so, you might be able to take most of the kink out of that spring and go on using it. You're not likely to make broadcasting demands of it. If you don't have that piece, someone might be able to give you the dimensions.
 
Do you have the wooden spacer that goes in the rectangular well the spring goes in? It's #84 in the diagram. I think its purpose is to keep the spring from kinking that way. If so, you might be able to take most of the kink out of that spring and go on using it. You're not likely to make broadcasting demands of it. If you don't have that piece, someone might be able to give you the dimensions.
That piece, the wooden one, is still there. The spring arches up without it. Something about the kink is making it difficult to get the tension right so that it goes into all gears, even with the adjustment screw. If it's loose enough to get into the last speed, it doesn't engage on the first. And if it's tight enough to engage on the first, it's too stiff to get it into the last. I tried to turn it around but that didn't work. I definitely need a new screw, but it might just come down to getting various springs and seeing which one will make it work.
 
You can mount the tonearm off the metal plinth in any B12 model, just rotate the metal plinth so that the speed control is on the upper left.
 
You can mount the tonearm off the metal plinth in any B12 model, just rotate the metal plinth so that the speed control is on the upper left.
I might also go mad scientist and get some uncut gasket to try to make something to isolate the tonearm from the rumble. I might have to get a slightly bigger ball bearing to make it work, or I might just end up taking it out.
Also, I found some odd odd washers that are cardboard or plastic on one of the primary bolts holding the motor to the plinth. DEFINITELY replacing that with neoprene or rubber to isolate that noise. Seems like a major oversight.
 
Can anyone explain how snubber capacitors work? I've bypassed the capacitor in the switch assembly in my B12H, and I'm wondering if I should be putting one into the circuit I have. Is it just a small value capacitor across the positive and negative of the AC power?
 
The snubber is installed as you explained in the circuit., a low value cap to keep any nasty arcing out of the switch.

FWIW, I'm relaunching on my ROK table. The size of the new DIY plinth kicked me to the curb, previously.. It is a good design but hard to execute (at least, I made it difficult). I have a nice Decca arm that seemed to fit the aesthetics well so that's what's going on there. I did most of the typical maintenance years ago so it should be ready to go.
 
I've now received most of the stuff to bring my old K33H back to life. New grommets, belt, 4uf cap, 5/16" ceramic ball, empire stylus from VM and I splurged on some 1/8" thick sorbothane rubber strip tape to replace the worn out foam where the top deck sits into the wooden cabinet. And 4 sorbo feet to replace the nylon jobs. I'm up to about $100 about half of which was the sorbo stuff <sigh>. Hopefully it wasn't money wasted. Printed a copy of the manual and have the wiring diagram in front of me.

A couple questions:
1. Is there any advantage of wiring the ac line with a 3 prong grounded plug with the ground attached to the metal structure and motor body? The original line cord is in good shape.
2. A previous owner ran a ground from the rca jacks over to the motor housing. I think that's a bad idea. The upper deck is wood so it's easy to isolate the tone arm from the motor drive unit and run a separate ground wire attached to the tone arm back to the amp. I haven't looked at the cartridge wiring yet in detail. Is just using the ground side of the rca jack sufficient if one channel ground is attached to the cartridge housing?
3. My objective is to get this back running close to original and listen to it for awhile before moving on so I'm way ahead of myself here, but I'll ask anyway. I've spent the last several hours researching possible motor upgrades that could be used to convert it to run multiple speeds and that won't break my bank. The Premotec 9904-120-18105 DC motor is used on a similar belt (string) drive turntable I found and looks like a possible candidate for the K33H. The spec sheet says it's available with ball bearings. All I can find are sleeve bearing versions. I'm not certain, but this might be the same motor Esoteric is using in their variable speed upgrade kit? The motor costs around $80 and would require fabricating a housing or mounting plate and making a new belt pulley on a lathe or a lot of work on a drill press with files and emery cloth. I've already got a variable regulated DC power supply to test it and with my free labor I think I might be able to do it for around $100 or so. Any other mods or ideas for doing this el cheapo?
 
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I've now received most of the stuff to bring my old K33H back to life. New grommets, belt, 4uf cap, 5/16" ceramic ball, empire stylus from VM and I splurged on some 1/8" thick sorbothane rubber strip tape to replace the worn out foam where the top deck sits into the wooden cabinet. And 4 sorbo feet to replace the nylon jobs. I'm up to about $100 about half of which was the sorbo stuff <sigh>. Hopefully it wasn't money wasted. Printed a copy of the manual and have the wiring diagram in front of me.

A couple questions:
1. Is there any advantage of wiring the ac line with a 3 prong grounded plug with the ground attached to the metal structure and motor body? The original line cord is in good shape.
2. A previous owner ran a ground from the rca jacks over to the motor housing. I think that's a bad idea. The upper deck is wood so it's easy to isolate the tone arm from the motor drive unit and run a separate ground wire attached to the tone arm back to the amp. I haven't looked at the cartridge wiring yet in detail. Is just using the ground side of the rca jack sufficient if one channel ground is attached to the cartridge housing?
3. My objective is to get this back running close to original and listen to it for awhile before moving on so I'm way ahead of myself here, but I'll ask anyway. I've spent the last several hours researching possible motor upgrades that could be used to convert it to run multiple speeds and that won't break my bank. The Premotec 9904-120-18105 DC motor is used on a similar belt (string) drive turntable I found and looks like a possible candidate for the K33H. The spec sheet says it's available with ball bearings. All I can find are sleeve bearing versions. I'm not certain, but this might be the same motor Esoteric is using in their variable speed upgrade kit? The motor costs around $80 and would require fabricating a housing or mounting plate and making a new belt pulley on a lathe or a lot of work on a drill press with files and emery cloth. I've already got a variable regulated DC power supply to test it and with my free labor I think I might be able to do it for around $100 or so. Any other mods or ideas for doing this el cheapo?
I think it would be nuts to replace the motor on that as it's one of the great motors in history, plus it would be a major pain. There are plenty of multi-speed players to work with if that's what you want or if you're going to make the whole thing from scratch better to make a motor pod or something like that than to make it fit an existing mounting setup. Less work and better result.
 
hehehe....sounds like I struck a nerve, lol. The advantage of modifying a k33h vs building a new table from scratch is $$$$ and if it improves performance as Esoteric claims then why not? I do appreciate originality to a point. When I restore an old amp I don't save the wrappers from the old wax caps and try to masquerade their appearance if they're under the chassis. And I'll rip out every selenium and maybe even modify a circuit if it improves performance. I might cut a twist lock electrolytic in half and re-stuff it though. This mod is in the same vein. It could be reversed, nothing gets ruined or damaged, and it's invisible except for the variable power supply needed to run the motor. I might be able to make an adapter plate that mounts the new DC motor to the existing shift plate and continue using the Lords grommets setup. Or in the worst case make a new shift plate like Esoteric did. BTW I did find another version of that same motor I quoted that has a tach sensor attached on the non-drive end and discovered it is used on a Linn turntable. There was a listing on ebay France last year from a seller with a quantity of them for only 8.8 Euros each!...that's like $10. If I find some that cheap I'm loading up. Regarding building a whole new table: A good platter from diy hifi with a spindle bearing goes for over $450. Using a thinner platter might get your costs down to $250. Making one on my own isn't cheap either. A nice chunk of 1.5" thick acrylic is expensive and you still need the services of a big lathe to turn it into a platter. It's easy to rationalize the prices charged by some of these outfits when you contemplate building one from scratch and in this State you can't open your doors for business without coughing up substantial taxes and fees every time you take a breath. I doubt any of these guys are getting filthy rich even selling tables at $2400.
 
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Rondine Jr. L-34
I didn't set off looking for a new project, but it looks like I have one!
I kind of forgot that I had this stored away, until I saw a wanted ad on barter town. I was apprehensive about selling it to anyone because of the unknown condition that it was in.
The AK member looking to buy found something local, so I figured I would at least go through it and have a idea of what shape it was in.
The tonearm and head shell are hacked up badly. The motor mount looks to have been dissembled and possibly reassembled wrong.
My biggest concern was the wire at the motor, the insulation was cracking all over the place and I could see exposed wire at the opening to the motor case.
I took the motor case apart hoping to get better access to the wire and I used liquid electrical tape to coat the exposed wires.
I cleaned and re-lubed the inside of the motor and it looks to be in pretty good shape.
I have placed an order for new rubber mounts, a ball bearing and Teflon washers.
I'm not sure if spending any more time on the tonearm is just a waste. It was originally a mono 120 that was rewired for stereo, like I said it is hacked up.
The head shell and tube connection plugs were removed and the tone arm wires are going directly to the cartridge.
My plan is to get the table and motor relatively quite using the original pith and idler wheels before spending a lot more time and funds on the pith, wheels and tonearm.
I would be interested in good tonearm options for this table, if anyone has ideas.
Is there a pictorial guide for this table anywhere? It would be helpful getting it back to the original setup.


Rek O cut L34 _2.jpg_DSC0842.jpg_DSC0851.jpg_DSC0841.jpg_DSC0844.jpg
 
You can download the instruction manual at vinylengine.com. Free registration and then you can download.

The idlers can be serviced by Gary @ voiceofmusic.com. Clean the inside of the platter rim, there might be buildup from the idlers over the years.

Looks like someone added an on / off switch and indicator lamp.

If you have any pictures of the process or insides on the motor it would be helpful for folks down the road if you can post them. Also, a picture of the tag on the inside of the plinth. I've never seen that one.

Good luck with your project.

Edit: Some links on other rebuilds:

http://jelabsarch.blogspot.com/2012/06/rek-o-kut-tips.html

https://www.stereophile.com/content/listening-120

https://www.stereophile.com/content/listening-121

https://www.stereophile.com/content/listening-122-part-2
 
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You can download the instruction manual at vinylengine.com. Free registration and then you can download.

The idlers can be serviced by Gary @ voiceofmusic.com. Clean the inside of the platter rim, there might be buildup from the idlers over the years.

Looks like someone added an on / off switch and indicator lamp.

If you have any pictures of the process or insides on the motor it would be helpful for folks down the road if you can post them. Also, a picture of the tag on the inside of the plinth. I've never seen that one.

Good luck with your project.

Edit: Some links on other rebuilds:

http://jelabsarch.blogspot.com/2012/06/rek-o-kut-tips.html

https://www.stereophile.com/content/listening-120

https://www.stereophile.com/content/listening-121

https://www.stereophile.com/content/listening-122-part-2

Thanks for your reply!
I don't need a operating manual, as much as I need a parts list/diagram like this one for the B12.
Mine is missing some parts when it was put back together and I would like to figure out what it needs.

REK006.jpg

I want to make a bit more progress before I decide about sending out the idler wheels for service.
The wheels don't seem to have much wear, they measure close to the original diameter and are not rock hard or glazed. I would like to hear what they sound like as is.

Sorry, I didn't think to take pictures of the inside of the motor when I had it apart. The label is for the wiring of the replacement stereo cartridge.

I have checked out the links, lots of good info there.

Any thoughts on 120 arm or a good replacement?
 
I want to make a bit more progress before I decide about sending out the idler wheels for service.
The wheels don't seem to have much wear, they measure close to the original diameter and are not rock hard or glazed. I would like to hear what they sound like as is.

The idler wheels don't "wear out", so to speak, but the rubber does get hard over time.
 
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