help needed! / Technics SL-1300 tonearm counterweight

jpciii

I like pizza
I recently picked up a clean Technics SL-1300. The counterweight was held on to the tonearm with scotch tape... hmm strange. I brought it home and figured out why. The counterweight has nothing to secure it to the tonearm. It just slides around freely on the arm. I found a little plastic bit that seems to have broken off of the tonearm. It was just laying there, luckily! **see pics for the broken part** There is also a threaded hole on the end of the tonearm. **see top pic** Am I missing a part that screws in there?

What do I need to do to fix this? I see new replacement tonearms listed, but they aren't cheap and nobody seems to stock them. Hopefully there is an easier way (assuming a new tonearm would actually fix this problem.)

THANKS:thmbsp:



technics_sl1300_ab.jpg


technics_sl1300_u.jpg
 
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I would say that you are very fortunate that you found that broken part. That looks like the kind of thing that you would never figure out if it wasn't found. It looks like the part that is broken, may put a friction (pressure) on the inside of the counterweight, giving it a positive resistance, kind of a grip on the shaft, that extends past the pivot. You may try superglue to stick it back on. I would assume with the semi circular ball facing out. Otherwise I don't know how much that tonearm can be dissassembled, to minimize the amount that you would have to purchase. You may need the whole arm. If available Good luck. CC
 
Yes, there is a groove inside the counterweight that takes a coil type path. The little nipple on the plastic bit fits inside the groove. When you spin the weight, it rides on the sprial groove and the weight moves along the tonearm.

I thought about trying to superglue it, but I would have to dissasemble the arm. I can't find any instructions on tonearm removal... I've searched. Anyone have a link?

thanks again:thmbsp:
 
for quick use of the tt i would messure the trakingforce and fix then the weight (ductape)
but u need a trackingweight scale these are cheap to buy from ortofon
 
From my experience with other s-arms, I'd bet that the black cylindrical part unscrews off. There may be a set screw somewhere that would have to be loosened first--not sure. Then just a matter of finding a junker and replacing it. You shouldn't need to replace the entire tonearm. Also need not be a 1300; the 1400 and 1500 would also work, and maybe others, but alas a great site that had all the pics of Technics turntables exists no longer, so no fast way to check.

Of course if Cosmic Charile's repair suggestion works, then wonderful.
 
In your second pic it looks like a set screw directly inline w/ the short shaft, on the round pivot, on the bottem. removal of the tonearm would be necessary to acess the screw tho. Altho there may be an easier way. It may unscrew like hakaplan suggests. good luck let us know how you make out. CC
 
It is very common for the counterweights to lose "grip" on their shafts and to just hang loose.

Often I will thread lengths of rubber band between the shaft and the hole in the counterweight. I will then adjust the counterweight to spec and trim the excess rubber band with a sharp knife or diagonal cutters.

I use the Shure stylus force gauge to do the adjustment.

Other times, the counterweight is so loose that the rubber-band trick doesn't work. Then I'll use a silicone-type glue -- and I'll apply this behind the counterweight so it's not plainly visible. This requires that, before applying the glue, I set the stylus force for one or two tenths of a gram too heavy to compensate for the mass of the glue itself.

Best,

Fred Longworth
 
The threaded hole at the end of the arm is to add more weight for balancing the arm with heavier cartridges like the Denon 102 mono cartridge.
 
Ahh. Thanks.

I don't have any updates for this. I'm thinking I'll just get a cheap tracking force gauge and use a dab of silicone sealant to secure the counterweight... you know, "set it and forget it". That means I have to spend money on a gauge, though...
 
The threaded hole at the end of the arm is to add more weight for balancing the arm with heavier cartridges like the Denon 102 mono cartridge.

Yes.. My SL-Q2 has that same threaded hole for that purpose, whereas my SL-DD22 does not and has a screw that passes through the back of the weight into that hole. The plastic bit locks the weight at different "stops" further forward or back on the arm for compensation when using different cartridges and/or heads, or the extra weight Stanton681EEES described as well as provide tension for dialing in the tracking weight.

slq2weightsm4.png

Typically, I've seen that type of wear more often when the table was in commercial service. The SL-1300 was a favorite among DJ's in the disco heyday, which is when this model was produced. If precise tracking is important to you, consider replacing the tonearm. The retail on your table in 1976 was $350 so a tonearm upgrade would definitely be justified.

Here's a link to an exploded view of the SL-1200 tonarm:

http://technics.junglist.pl/schemes/M3D_tonearm.jpg

Yours should be similar if not interchangeable. New Technics replacements are available for as little as $60, even less on auction sites. Check with a few DJ supply houses for the best price.

use a dab of silicone sealant to secure the counterweight.

Never tried this.. but perhaps a couple thick dabs of silicone in the slot behind the plastic bit might hold it in and build it up enough so that the play in the silicone restores the tension you need to keep the weight in place and adjustable. I'd let it dry in a more protruding position before putting the weight back on.
 
I have the same problem with my 1300 but have no idea where the piece is. I added material to the arm to create friction and used my Shure gauge to set the weight. You might try a piece of masking tape around the back of the tonearm. Patrick
 
I just attempted a repair... I put Blu-Tac in the cavity, and super-glued the piece back on. So hard to get to with the arm still assembled! The Blu-tac helped position it while trying to get it back where it goes, and hopefully will keep the pin at the correct spot to do its job. I'll post after it drys, and I feel brave enough to twist on the counter weight!
 
OK, so 4 years later, I see in my photobucket account's 'stats' that these pics are getting a bunch of hits...

I never did actually fix this. I have been using and enjoying this table for years, however. I wrapped enough tape around where the weight goes to *sort of* hold it in place. I'm still able to move the weight with some effort and I can set tracking force using a gauge. It's a ghetto situation, but hey... that's just part of the charm of vintage audio, right?
 
Hi jpciii , 7 years after your original post I came through exactly the same situation with my SL1300.

I found a fix, so I decided to register to this nice forum and post the idea.

A piece of high density foam , or natural cork is needed. I found the right stiffness after trying some nice vintage wines.

Now, seriously, take a piece of a cork stopper, or the new silicon made stoppers from a wine bottle, cut it in a shape that will go through the hole in the arm (that is basically the same shape as the broken plastic piece) and make it tall enough as the arm gap inside, plus 1mm. This will act as a spring.

Glue the plastic piece to the bottom of the cork 'spring', put the assembly it into the tonearm hole. Cut the upper side to adjust the height, more height on the front side. Try the counterweight now.

The nice thing is that you will not need to glue the piece inside the arm, and you can trial and error for the cork size (or silicon equivalent)

I have made no pictures yet but if anyone is still interested I can upload them.

Greetings.
 
Hi jpciii , 7 years after your original post I came through exactly the same situation with my SL1300.

I found a fix, so I decided to register to this nice forum and post the idea.

A piece of high density foam , or natural cork is needed. I found the right stiffness after trying some nice vintage wines.

Now, seriously, take a piece of a cork stopper, or the new silicon made stoppers from a wine bottle, cut it in a shape that will go through the hole in the arm (that is basically the same shape as the broken plastic piece) and make it tall enough as the arm gap inside, plus 1mm. This will act as a spring.

Glue the plastic piece to the bottom of the cork 'spring', put the assembly it into the tonearm hole. Cut the upper side to adjust the height, more height on the front side. Try the counterweight now.

The nice thing is that you will not need to glue the piece inside the arm, and you can trial and error for the cork size (or silicon equivalent)

I have made no pictures yet but if anyone is still interested I can upload them.

Greetings.

I am very interested in the pictures.

My girlfriend has an SL-1300 with this problem. I "fixed" it by wrapping blue painters tape around the arm to increase the friction between the arm and the counterweight. Then I used my Shure stylus force gauge to set the VTF --- there is no easy adjustments once the VTF is set. This is a brute force method.

Unfortunately, I cannot follow your desciption. The missing nub on mine is long gone I assume you are calling this the "plastic piece"? What do you mean by "tonearm hole"?

Pictures would be a great help!

There are probably a lot of people looking for a solution to his problem.

Thanks,

Bob
 
Hi jpciii , 7 years after your original post I came through exactly the same situation with my SL1300.

I found a fix, so I decided to register to this nice forum and post the idea.

A piece of high density foam , or natural cork is needed. I found the right stiffness after trying some nice vintage wines.

Now, seriously, take a piece of a cork stopper, or the new silicon made stoppers from a wine bottle, cut it in a shape that will go through the hole in the arm (that is basically the same shape as the broken plastic piece) and make it tall enough as the arm gap inside, plus 1mm. This will act as a spring.

Glue the plastic piece to the bottom of the cork 'spring', put the assembly it into the tonearm hole. Cut the upper side to adjust the height, more height on the front side. Try the counterweight now.

The nice thing is that you will not need to glue the piece inside the arm, and you can trial and error for the cork size (or silicon equivalent)

I have made no pictures yet but if anyone is still interested I can upload them.

Greetings.

This picture illustrate what I did, also suggest how to substitute the plastic broken piece , if missing, with a pin. You just need to find a pin with the right head shape.

@bobins8 . for a pic of what I meant when I referred to the hole under the tonearm rear plastic section please see the second pic at the beginning of the thread.

corcho%20sl1300.JPG
 
I have to say, it seems like a trivial problem, but in my experience I have had to replace the tone arm to make it an acceptable fix. I have tried to use epoxy and JB weld to glue the set piece back into the slot, but it doesn't seem to work or last.
 
This picture illustrate what I did, also suggest how to substitute the plastic broken piece , if missing, with a pin. You just need to find a pin with the right head shape.

corcho%20sl1300.JPG

Nice work! A marvelous solution! Welcome to the site and thank you for posting.

I still listen to my SL-1300 and have been enjoying it with a Grado Red. Trying different cartridges is a big hassle - always have to use the gauge, and the counterweight is difficult to adjust. I would like to play around with different carts, so I will attempt your method of repair... as soon as I find the little plastic piece! I've been looking but haven't found it yet. Perhaps when I added tape to the tonearm to create friction for the weight, I may have stuck the plastic piece up into its slot for safe keeping. I will be annoyed if I tear apart my "repair" and the plastic piece is not there.

I will try to post updates soon...
 
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