SL1200 upgrade tonearm or replace cartridge?

I read somewhere, and maybe someone else can speak more definitively, that the servo circuit within the SL motor is constantly hunting for the proper rpm. While looking at the strobe it appears to be visually stable but the motor is continuously compensating.

I believe that's a widespread myth, and am pretty sure I even read it in Stereophile once. However, I've never seen any evidence that it's true, such as measured speed or pitch variations. Some people feel that the SL12x0 series has an upper midrange glare or resonance, and since the servo operates at 3500 Hz, some audio journalists *theorized* that the servo frequency caused the glare, but then passed it on as fact.

I've read on the KABUSA.com site that this is false, and he has the 'scope captures to prove it. In my personal experience with my SL1210 M5G (and AT150MLX for that matter), I set about to neutralize all resonances and vibration I could find. There *was* a persistent subtle glare in the upper midrange; when I flicked the tonearm with my fingernail it seemed to ring at the same pitch. The tonearm is an undamped aluminum tube, which by its nature is very resonant. I wrapped the tonearm in inexpensive lightweight Teflon pipe thread tape and the resonant peak disappeared.

Most of the complaints about the Technics lack of clarity can be readily and cheaply addressed with damping and vibration control. I upgraded the headshell to a pretty inert LPGear ZuPreme, installed KAB's fluid damper, wrapped the tonearm, swapped in a sorbothane platter mat, replaced the stock feet with brass cones situated on inverted Vibrapod cones sitting on Vibrapod isolators sitting on a 3.5" thick heavy butcher block cutting board isolated by some silicone gel pads. It sounds convoluted but cosmetically it actually looks OK and every tweak I mentioned incrementally improved clarity, musicality, lowered noise floor, improved dynamics, etc.

Yes, the Technics has some resonant peaks and some clarity problems out of the box, but they have nothing to do with the servo frequency and are inexpensively neutralized.

Don't forget that all the damping and wrapping come at a price. These are fixes to tame resonant frequencies, to move towards a more musical and less analytical presentation. I would love to put my 10' vpi tonearm from a Traveler on my KAB 1200 deck, I just can't seen to get past this gastly Technics tonearm. It just seems to take some of the life out of the music.

02-07-13: Zenblaster
Don't forget that all the damping and wrapping come at a price. These are fixes to tame resonant frequencies, to move towards a more musical and less analytical presentation. I would love to put my 10' vpi tonearm from a Traveler on my KAB 1200 deck, I just can't seen to get past this gastly Technics tonearm. It just seems to take some of the life out of the music.

I don't get what you're trying to say. All the damping tweaks I mentioned improved the sound. It didn't just reduce midrange glare, it improved inner detail, linearity, microdynamics and macrodynamics. The sum total is that with these tweaks the music is more lifelike and involving.

The only place I encountered overdamping is if you put too much silicone goo in the KAB damping trough--then the dynamics flatten out and the music turns lifeless. This is the universal symptom of overdamping. This is easily fixed by filling the damping trough only one-third full.

Each tweak fixed something different. The record grip damps spindle and surface noise. The mat damps platter ringing; the tonearm wrap damps tonearm ringing. The brass cones/vibrapod/cutting board drain extraneous vibrations out of the chassis; the gel pads under the cutting board isolate the turntable from room vibrations. Each tweak addresses a different set of vibrations and resonances.

As for "coming at a price," it was $150 for the KAB trough, $10 for a used sorbothane mat, $50 for the headshell, $20 for brass cones, $56 for Vibrapods, $25 for a rubber record grip, $89 for a big, heavy cutting board and $30 for two computer keyboard gel wrist pads. The results were improved musical reproduction in every way with no subtractions.

I'm saying that I made the error of putting too much effort and modifications (and money) into a, relatively speaking, poor tonearm. Any of the aftermarket tonearms that the op mentioned will get you further up the food chain, by far, than any modification and tweak you can make to a $50 tonearm. I know I may be stomping on hallowed ground but I have owned and used a Kab 1200 for years. Ease of use, quick cart changes,great sound, I love it, I even have an Ortofon 2mBlack on it as I speak. The VPI Traveler that I've been trying out is just in a different league and most of that difference comes from the tonearm.
It's the law of diminishing returns.

Has anyone tried a VPI tonearm, such as a JMW 9t on a SL1200?

I kind of share zenblasters view why put money and effort into something that is fundamental flawed.

Johnny I've tried the Teflon wrap, the improvement was marginal at best.