suitable tonearm for audio technica AT-150mlx

IMHO option, either arm will work very well with that cartridge. I've used my AT150MLX on a Rega RB600, Audioquest PT9 and a Zeta(van den Hul) all with excellent results.

The AT-150MLX is not a relatively high compliance cartridge.

12-23-11: Audiofeil
The AT-150MLX is not a relatively high compliance cartridge.

You are correct, sir. The AT150MLX has a dynamic compliance rating of (x 10-6 cm/dyne, 100 Hz): 10.0. The Ortofon 2M series is about a 20, the Grados a 25 and the Shure M97xE a 30.

The AT150MLX makes for a 10.89 Hz resonance on a 12.5g arm, which is close to ideal; on the 14g arm the resonance drops to 10.53 Hz which is theoretically better, but probably insignificant. I'm using a Technics SL1210 arm with an AT150MLX mounted on a 14g (or thereabouts) headshell making for a total effective mass of about 18.5g (plus the 8.3g cartridge) and the resonant peak is also a near-ideal 9.62 Hz. So as you can see, with 10 Hz being the ideal resonant peak, the AT150MLX comes very close to that with a tonearm whose effective mass ranges from 12 to 19 g.

While the 150MLX is not a high compliance cartridge, you might have problems with a 19g arm. 100Hz cu figures are not directly comparable to standard 10Hz numbers. The equivalent 10Hz figure for the 150MLX is around 18cu.

Many people seem to get good results using an arm heavier than recommended. Much depends on set-up, physical and acoustic isolation and the particular arm and cartridge in question. Also, resonance estimators are just an estimator and results often vary. Sometimes an arm heavier than ideal can sound sluggish with a higher cu cartridge. Because of other factors such as electrical loading, results seem to vary widely. By all means try it. With that cart it's recommended that you keep the total capacitance load as little as possible. < 200pF is recommended for most ATs.
Regards,

you've all been very helpful - thanks very much from "old" England. I do actually have a spare unused stylus so if anyone happens to have an unwanted body or a body with a worn out cartridge perhaps you could let me know. Then I could have an AT-150 mlx on both arms (having unfortunately had an accident with my OC-9).
Thanks again
Alan