No. Rabco had a proportional drive.The Rabco ST-4/5/6/7/8 arms all used this principle (by mechanical means, not electrical) and work very effectively.
Yes. What do you think proportional means?No. Rabco had a proportional drive.
The arm carriage will move across the record of it's own accord In @ 20 minutes (assuming correct adjustment) if the needle is lifted out of the groove.
Proportional means proportional to the deviation from tangential.Yes. What do you think proportional means?
The arm carriage will move across the record of it's own accord In @ 20 minutes (assuming correct adjustment) if the needle is lifted out of the groove.
An ST7 dropped into my lap about three years ago. It is what it is, neither a spectacular deck nor a terrible one. Once you've had the, er... "pleasure" of setting one up you'll understand why later manufacturers dropped that linear tracking scheme like a red-hot stove in favor of servo drive.
My impression was that it wasn't particularly robust once adjusted, either. To say that f**ting in its general direction would knock it out-of-whack is only slight hyperbole. Perhaps it worked much better when new and that the then-current performance had been compromised by the age of the rubber components, different lubrication, etc. I really don't know. The Rabco arms do have their followers though, and each system and its environment is different - so maybe there's something I'm missing.
I had fun messing about with it, but at the end of it all I came to realize that I'd experienced vastly better performance from my "conventional" turntables. Your mileage may vary, etc. & etc...
My impression was that it wasn't particularly robust once adjusted, either. To say that f**ting in its general direction would knock it out-of-whack is only slight hyperbole. Perhaps it worked much better when new and that the then-current performance had been compromised by the age of the rubber components, different lubrication, etc. I really don't know. The Rabco arms do have their followers though, and each system and its environment is different - so maybe there's something I'm missing.
I had fun messing about with it, but at the end of it all I came to realize that I'd experienced vastly better performance from my "conventional" turntables. Your mileage may vary, etc. & etc...
Attachments
Last edited:
I agree with your findings, and will add that that "type" of design didn't last long.
And indeed, the change to electronically-maneuvered linear arms is miles ahead in performance, stability, and reliability.
My Kenwood only needed a new cartridge in all the years/decades that I've owned it, it never gave me grief.
Of course, I did provide some pro-active maintanance to insure peace-of-mind for decades to come.
And indeed, the change to electronically-maneuvered linear arms is miles ahead in performance, stability, and reliability.
My Kenwood only needed a new cartridge in all the years/decades that I've owned it, it never gave me grief.
Of course, I did provide some pro-active maintanance to insure peace-of-mind for decades to come.
Last edited by a moderator:
That's f..g genious.Thank you for sharing the idea.Never heard about it before.
- Home
- Source & Line
- Analogue Source
- Approximate linear tracking arm idea.