Rabco SL-8E Vs Top Quality Pivoted Tonearms


I am very curious to find out your opinion on the following question……is a Rabco SL-8E linear tracking tonearm (in top operating conditions) as good as a top quality pivoted tonearm such as Graham 2.2, VPI JWM 9, Triplanar, etc., etc. while concidering the following parameters.
The Rabco is not the top quality linear tracking arm ever made but it has the inherent advantage of being linear tracking (as similar as possible to the cutting tool) where the Graham, VPI, Triplanar, etc. are top quality arms in built quality and design but have the shortcomings of a pivoted approach.

So, given the lower quality but better methodology for tracking of the Rabco against the higher quality but less accurate approach for tracking of the pivoted arms which one do you believe will render, all else being equal, the better sound reproduction the Rabco or the Graham, VPI, etc?
ruben1

Showing 2 responses by notbananas

If anyone is interested, here is a link to a detailed history of linear tracking arm designs and manufaturers, including the Rabco:

http://www.soundfountain.com/amb/ttrabco.html
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I owned one in the early seventies running on a Techniques SP10 turntable. It was a fun toy, but the mechanism made so much noise that even at 15ft. from the arm, I could her the chain drive motor when it was activated to move the arm and the bead chain noise. it uses the same type of bead chain as you have on your house keys (real high tech).

Also there is a mechanical switch which has to make contact in order for the arm motor to advance. This obviously presents a lateral force against the needle in the cartridge since this switch has to make contact, thus defeating the reason to have a linear tracking arm. Because of this, it has a small amount of distortion as the arm is pressed against this switch before it's closed, but the needle is trying to move the arm without success. Also, there's always a small amount of tracking angle offset because the arm does not move continuously. It moved only when the angle of the arm is sufficient to activate and close the motor switch. This, according to the manual, is "only" about 1/6th degree of arm movement.

Aside from these issues, the actual arm is just a U shaped bent piece of metal which I can imagine has a resonant frequency well within the audio range. This arm is ompletely un-elegant in design and funtionality.

Rube-Goldberg would have been proud of this contraption.

BTW, you can Google the arm and find the manuals and several pictures.

Fortunately I sold it after several months of screwing with it trying to be more responsive to the mechanical actuator switch.