The Sonex SX 500 turntable was designed and manufactured in Switzerland by Werner Eglauf AG, Forch/Zurich Switzerland.
3 versions existed, most had the SME 3009MKII or sometimes SME 3009 improved tonearm installed.
Very few the Ortofon AS212 tonearm.
All had a precision bearing for the long 8mm shaft of the subplatter
a) Simple version with black plastic subplatter + very light aluminium platter
b) Precision machined metal subplatter + very light aluminium platter
c) Precision machined metal subplatter + heavy ca 3kg precision machined aluminium platter
Version c) is the one to go for, b) isn't bad but the light platter is not recommended, almost impossible to find
the heavy platter as it never appears on the 2.nd hand market.
The motor is a special 48-pol synchronious motor.
This motor runs with 110V with a simple R/C phaseshift powersupply.
It can be bettered with an electronic powersupply or a Naim Geddon Clone or Naim Armageddon.
The Linn Valhalla was sometimes uses with success because the mechanical speed change allowed 33/45 rmp with a pulley
made of aluminium precision machined.
The motor is fixed to the chassis with 3 scews. Two of the fix, one of them with a strong spring which can be adjusted from the top.This
Soundquality was very good but with an electronic PS it thrilled.
The rare version with an Ortofon AS212 tonearm was the best. This tonearm was used in Switzerland as well on the Thorens TD124MKII
and is known to be an excellent tonearm.
Those 3 versions had the knob for speed-change on the left front side. In the middle front was the On/Off switch
d) "Revised" 4th version came on the market with a slighly different design:
The knobs for speed change and On/Off were now on the right side below the SME 3009, all the other parts remained the same, but it was only delivered with the light aluminium platter.
So version c) is the most desired one, particular if with Ortofon AS212.