Rabco SL-8E Tone Arm

Is having equal vertical and lateral mass a part of the definition of a linear tracking tonearm? I would not think so. I guess you meant that it is one of the best SLs you've used, because of the low lateral mass, as opposed to any air-bearing SL tonearm which will have a high lateral mass. I have seen the issue of lateral mass argued both ways, high is good; high is bad. I have no dog in that fight. I think high vs low has to do with whether you use a high or low compliance cartridge, but could be wrong.

But as I have pointed out other posts you can minimise cantliver flex in tangential air bearing arms by employing electromagnetic damping. I used a Shure V15Vmr on an ET2 for about 6 years and the cantilever is still as straight as a die. A small ( nickel size for you guys ) ring magnet under the beam accomplishes this.
Servos are like Digital, they are only a little bit out all of the time. Sitting in the listening chair, with a Goldmund Studio, watching the servo lights go on and off constantly with a $10k cartridge on the end is not my idea of relaxing to music.

The question is- not is the cantilever straight now, but is it straight the whole time the cartridge is tracking? If you can see it flex side to side even a tiny bit, then a radial tracker or the Rabco will have lower 'tracking distortion'.

Atmasphere, yes I get that and I dont think there was any difference in deflection on eccentric records between a conventional arm and the ET ( with the dampening applied). The amount of deflection will vary depending on the horizontal compliance of each cartridge. The Dynavector arms use the same electromagnetic horizontal damping to counter the high horizontal mass in their biaxial design.
Possibly a case here for low compliance cartridges if we assume many records are off centre.

all technical things aside these arms when setup + working like they did when new... play music period! most others can only dream of...top to bottom they are excellent IMO...I have several including a highly modified balsa wood armwand one that has censor switch instead of the mechanical one...

Lawrence
Musical Arts