SL1200 upgrade tonearm or replace cartridge?

Original arm.

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 this function was accomplished with regulation independent and outboard of the motor in the SP-10 whose subsequent versions improved on those electronic controls and its power supply.

Back in the day most of the radio stations my wife worked at as well as others I visited the SP-10 and 15 became the mainstay in the last days of vinyl. The arm most often used was an older Ortofon RMG 309 (I think), with an Ortofon SP cartridge. I'm sure there is a newer more elegant and expensive version.

These things were a very long dog leg and were also used in conjunction with the older idler tables. With the table off the disc jockey would spin and queue the track, hold the queued record while he turned the table on and the felt topped plater would spin under the queued record then let go.

Try a Audio-Technica AT150MLX MM cartridge on your Technics. I use one, and it's a great combo. Highly recommended.

Vic, I think the "life being sucked out" effect you describe is most likely due to the stock tonearm more than the table as whole.

As for the speed searching, this is not my experience. My 1200 is absolutely stable, quartz locked at the correct speed. Maybe if you add additional weight to the platter, with copper mats and heavy clamps, such as TTW, then you may run into some torque issues.

Dave as I mentioned above, I find the at150mlx intriguing but I am totally satisfied with Benz Glider homc. I have not intention of going back MM at this time. If I did, I would probably like to try a Grace f9 ruby first.

I would like to redirect this thread back to my original questions.

1- Should I replace my cartridge which is nearing (but not yet there) it's end of useful life before upgrading my tonearm? The logic, is that new cartridge may provide sufficient improvement in performance thus putting into questions the need for a tonearm upgrade. However, a having a new cartridge may limit my selection of compatible tone arms, thus putting off the replacement cartridge until I have upgraded the tonearm would allow me full flexibility to change to an optimal cartridge for the tonearm selected. What came first the chicken or the egg?

2- I am leaning towards an SME arm, who has experience with these arm on the sl1200, at which would be best 309, IV or V, and are there any to avoid? Yes I realize that conventional wisdom would suggest that these arm may be overkill for the table.

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.