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In part one of my How to rewire a Technics tonearm I displayed some pictures of a broken part requiring replacement.
I demonstrated how to melt back the Cardas tonearm wire insulation efficiently and without waste with a standard soldering iron.
There was a picture showing some concealed damage to the stock arms main horizontal bearing piece.
In this edition I have some fun new pics for you to digest.
First, you have at least a dozen or more ways to approach the rewire. This is a friend's tonearm. We decided to rewire the arm tube with Cardas 33awg tonearm wire from the bayonet to the base.
John wanted to evaluate some very slick looking Belden cable from the base to the phono section. The best thing for John is that we can easily change the base to phono wires should he not enjoy the Beldin cables.
This first picture shows how the tonearm works. The main tonearm assembly consists of four basic structural components. The outer casting is the piece that screws down to the table. Its primary job is to act as a solid back bone. Its extra functionality is to supply a mechanism to allow vertical tracking angle variation on the fly.
The second assembly is a precision machined brass ring that allows extremely precise vertical adjustment due to its fine pitch threads. It will allow 6 millimeters of vertical adjustment which should be plenty more than most cartridge swaps will require.
The third piece shows a broken arm retainer. This piece is the tonearm base which provides the tonearm lift, retention and bias adjustment.
The final piece is the main horizontal tonearm bearing assembly. This one is uterly destroyed. On the other two arms John sent me the bearings are precise and effortless.
Picture two shows the actual damaged lift piece that plugs into the base and provides for arm lift and bias control. The anti skate mechanism utilizes a spring assembly which allows excellent and repeatable bias adjustment and you can accomplish it on the fly.
Picture three shows the bayonet assembly. The pins are spring loaded. I used a head shell during the solder removal and replacement steps to provide a heat sink. Remember to remove the cartridge before doing any soldering.
Picture four shows the fully assembled technics arm with the stock PCB for the tonearm wire mounting. You can see the stock wires coming from those big bulbs of factory solder.
On the upper right side you can see the slot where the stock wire looms through providing important stress relief.
The Beldin wire we are running from the base to the phono inputs is huge. Even a single wire would not fit in this slot without extensive modification. The stock piece is secured in only two spots. The Beldin wire is too heavy for long term use with this board. So off it came.
Picture five shows the new fabricated tonearm wire board.
First it picks up three mounting positions which provides a more stable platform. Second I drilled it for a precision fit to the upper right and left mounting points that offer positive capture points to prevent rotation.
DrLowMu mentioned he hates PCB traces for tonearms. One big benefit of building a custom piece is the ability to directly solder the Cardas wire to the Beldin Wire. This should allow superior sound transmission.
On the finalized custom board I drilled holes to fit the Beldin wire and secured each wire with a nylon tie strap. I then secured the two wires with a third tie strap. This wire is going nowhere.
After soldering the Cardas wires to the Beldin wire I used some hot glue to provide stress relief.
The wires are superb and should last a lifetime.
The Technics arm is both simple and elegant. It has world class engineering and sounds great stock. Rewiring is fairly simple and straight forward. Use a heat sink, prepare all the wires before making final solder connections and use heat shrink to eliminate any possibility for shorts.
Follow Ups:
Tubes ,
Thanks for sharing ...
Do you have any experience in rewiring a SME tonearm. Plan to re-wire my SME3009 S2 detacheable headshell but no reference on how to do it. Hope you can share some infos.
Cheers,
jm .
Worked really well. I also did an adaptation for the Pete Riggle VTAF on the SME main vertical bearing assembly. Here is a picture.
Again, the important thing is to use a heat sink on the spring loaded bayonet assembly. Otherwise you get fresh wires and cooked connectors.
You can select the tonearm wire of your choice. Your SME is fairly easy to rewire. If you have the RCA pick ups on your base you are lucky. If not you might want to buy an RCA adaptor for the arm or run the wire continuously from the clips to the phono section as my project was designed.
The first edition shows how to clean up the wire so you can easily solder it to a pin or post.
Any reports yet on how well it works?
Ken
All you need is love, a good steak, and a good alignment protractor!
The cable is Belden 1505F. Here is a link to the specs.
The arm will be going on a Technics SL1800MKII. I wanted to prime and paint the plinth before installing the arm but we have had such crappy weather here in Ohio, plus I was waiting to get the main board back as it needed some parts replaced.
I'll post sometime next week on how it sounds.
I've often wondered how well that would work as a phono cable. The main differences I see between the 9259 and the 1505F are the 1505 has a double tinned copper shield where the 9259 has a single bare copper braid shield. The center conductors seem to be slightly different as well. I'm not sure what difference that makes, but it is different.
Ken
All you need is love, a good steak, and a good alignment protractor!
Three GHZ HD coax cable. Multistranded copper center and some of the best braided shielding I have seen on a coax cable.
Hopefully John can post about the sound in the future.
I did a SL-1200 arm a while back. Decided to run the Cardas wires all the way to the phono. I still picked up grounds from the PCB to bring out to the phono stage.
The SL-1200 provides stress relief with the bracket that mounts to the bottom of the arm.
BTW, thanks for providing this info. When I did mine details were sketchy at best. The disassembly of the table and arm removal kind of fell into place. The removal of the headshell mount was where the adventure began. Mine was stuck. It would not move. Took some real work to even get it to budge. Finally got it out. Polished it a little to get it to go back without a hammer. Then added a little Locktite to lock it in as solid as stock.
Results are great. The arm is definately a weakpoint sonically.
George
From a purist stand, I think a single run should give you excellent sound with repeatable results.
On a variety of high quality tonearms you will have a DIN or JIN connector at the tonearm base. This lets you spin tonearm cables and system match your sound.
I have enjoyed the sound of many tonearms. Some tonearms employing multiple connectors can sound better than my project arms utilizing a continuous Cardas run. For example the Magnepan Unitrac arm has many connection points but still beats any of my current project tonearms.
Most of my DIY projects utilize continuous wire runs.
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