EternalArts turntable motor control TMC


The EternalArts OTL motor control transfers the ingenious Futterman idea of ​​a transformerless tube amplifier to a high-precision power supply for motors in high-end turntables. It is a 2-channel OTL tube amplifier based on 11 tubes for the two speeds 33 and 45 rpm with sensitive fine adjustment and display of the speeds via Nixie tubes. There is nothing that drives a turntable more smoothly than this OTL.

  • Compact control module for the connection of a 2-phase synchronous motor implemented in a two-part powder-coated sheet steel housing with a high-gloss black acrylic front, solid nickel-plated feet and buttons turned from solid metal

  • Separate fine adjustment for speeds 33 and 45 rpm

  • Optimized for all Transrotor drive motors

  • Display of the speeds with Nixie tubes

  • Can be converted to operate with other 20V motors

  • Circuit design with a total of 12 tubes plus 2 Nixie display tubes

  • Board-supported structure with gold-plated, 70μ double-sided laminated conductors

  • Cast multi-voltage transformer using toroidal core technology

  • High quality selected components

  • Multiple secured, absolutely stable circuit for maximum safety and a very long tube service life

  • Made in Germany

  • Warranty 1 year (tubes limited)


Technical data

Input / driver stages 2 x EF 184, 2 x EF 94
Power amplifiers 4 x 6CJ6 (EL 81) je Kanal

Display tubes

2 x Nixie NH 125


22 (width) x 20 (hight) x 30 (depth) cm

Temperature range

10° to 35°C  =  50° to 95°F

Humidity range

20 – 80%

Black high-gloss powder-coated sheet steel chasis and hood; high-gloss acrylic front, buttons and feet high-gloss nickel-plated or black anodized


Foil-shielded high-end power cable

Mains voltage

Power consumption

230 V ~ 50 / 60 Hz

76 VA (unloaded)
127 VA (loaded)


8 kg net = 17,6 pounds 

Subject to change without notice

Circuit description

A 2-channel OTL amplifier with 4 x EL81 per channel is configured in such a way that it outputs two phase-shifted voltages of approx. 20V. A generator generates the control voltages required for speeds 33 and 45 rpm, which are fed to the two OTL amplifier channels. The aim was to generate absolutely uniform voltages for a turntable motor. For the assembly, new tubes from old stock were used, which are still available.


  • Mains toggle switch, 2-pole

  • Nixie tubes for displaying the speed

  • Fine speed regulation for every speed

  • 6-pin Amphenol Tuchel socket

  • Foil-shielded high-end power cable

Classical High End