The Technics SL-1200 Tonearm
KAB Audiophile Times
June 2011 - The Mod Process - Page 3

Table Of Contents
Page 1......The Drive System
Page 2......The Tonearm
Page 3......The Mod Process
Page 4......Power Delivery
KAB Main 1200 Page

Building the Hot Rod Technics
  It is rare indeed that one is handed such a gem to work with. This state of the art, laboratory standard turntable would seem to have everything. True enough, yet even more performance can be coaxed from the 'table. And it can be done by improving the stock elements. There is no reason to strip and replace any of the well designed original parts.

The modification process should be approached by evaluating the main elements and understanding what comes from each improvement.

A tonearm rewire is the most noticeable mod you can do.

KAB SuperFlex Rewire
Let's start with tonearm rewiring. You already know that the stock arm is quite good mechanically. The stock wire however is another story. It is a low grade tin plated copper in a pvc insulation. Over time the chloride in the insulation attacks the strands literally turning them black in color. The oxidation creates semiconductor effects between the strands and this has the affect of darkening the treble response. By replacing the wire with KAB SuperFlex Litz 34 ga phono wire, correct sonic definition is restored to the arm. In Litz construction, each wire has 40 strands of pure 50 gauge copper and each strand is separately insulated. There can never be inter strand reactions of any kind with this type of wire design. This is perhaps the single largest, most obvious improvement you can make to your 1200. KAB SuperFlex uses a super flexible silicone insulation. SuperFlex is completely free of the static noises common with Teflon and Nylon insulations used in other brands of tonearm wire. We also dampen the arm tube at both ends with cotton. 'Tables can be terminated in RCA or DIN style connectors. Tonearms are available pre wired with Cardas.

KAB PC1200 Phono Jack Plate

Getting into the thick of it
  Fluid Damping all but eliminates wild low frequency arm/cartridge resonance. This lets the arm mate with a wider array of cartridges. It also prevents the wild and often destructive loudspeaker cone movement that can occur on warps. It also reduces rumble and acoustic feedback to speakers. It improves dynamic range and extends the bottom bass response to 15hz. Fluid Damping is a good thing.
KAB TD1200
Sonically, there is a slowing down of the entire acoustic event. There seems to be more "time" to listen. Fluid damping should be the second mod you consider. It is very easy to install. Here is a great A'gon review of the Fluid Damped 1200 Tonearm.

With the KAB TD-1200 the acoustic event seems to almost stand still. Allowing more "time" to listen.

Strobe Magic. Now you see it, now you don't !
That big red strobe lamp wow! Lets you see the speed accuracy at a glance true. But you know it's a quartz locked motor, so do you really need the strobe to tell you that? Well, perhaps at start up, but surely not all the time. So what's so bad about leaving it on all the time? That strobe lamp is powered with a sharp square shaped waveform and draws over 84 mA of current from the power supply. If you hold an AM radio close to the strobe you will see what that means. Lots of radiated EMF. You can actually see these current pulses on the main power supply which means that they are polluting the power lines throughout the turntable. Our SX1200 Strobe Disabler circuit lets you control the lamp; turning it on or off by holding the start-stop switch.
KAB SX1200 Strobe Disabler
This way, for the most serious listening sessions, you can keep the strobe lamp off. Eliminating sources of EMF is believed to make for quieter, blacker backgrounds. The SX1200 is available with pigtail leads or solder terminals.

Clean Green Power
Inside the 1200 is an AC power transformer. Though well shielded, it still allows between 10 and 50 Miligauss of EMF to envelope the phono cartridge. This is the low frequency kind of EMF that can induce hum into unshielded cartridges. In general it is a good idea to eliminate EMF wherever you find it.

  The KAB PS1200GX is our lastest external power supply design. It meets all the standards of the 2007 US Energy Independance Act while providing a source of power that is as clean as running the turntable on batteries.
The design uses a unique noise cancelling regulator that reduces residual noise to the microvolt level. By cancelling noise you don't waste gobs of power as you would with a conventional linear voltage regulator.
Using the PS1200 eliminates the EMF radiated by the internal power transformer as well as providing a very clean power source to the turntable. The PS1200 can be hard wired into the table, or we can install a socket in the base of the turntable that lets you instantly switch between the stock original power supply by unplugging PS1200GX.

In general it is a good idea to eliminate EMF wherever you find it.

Other things to consider.
To set cartridge VTA successfully, your mat or mat system should be at least 3/16" thick. A good mat is the technics original MK2 mat. We call it the super mat - 17oz and nearly 1/4" thick. Sculptured on one side for 7" 45's and flat on the other side. I think the flat side is best for LP's. The thinner version of this mat which comes with the MK5 and M5G is useful as a top mat for the SDS Isoplat mat. That 2 mat system is great at eliminating all platter resonance. Lightweight mats alone will not dampen the internal platter resonance. And don't forget about isoloation feet and record clamps. These items can help in certain situations and enviroinments.

KAB stocks Cardas headshell wires and KAB now makes interconnects using Cardas shielded phono cable. Now you can have Cardas Litz wire from cartridge pins to the preamp input.

I hope you find this information useful as you contemplate the next step in improving your Technics SL1200 turntable. It has taken many years to turn popular opinion, but the proof is in the many audiophiles that now embrace this laboratory grade marvel of mass production. Get started here: Modding Your Technics 1200.

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