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)

More information about the EternalArts turntable motor control TMC

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
Dimensions	22 (width) x 20 (hight) x 30 (depth) cm
Temperature range	10° to 35°C = 50° to 95°F
Humidity range	20 – 80%
Material	Black high-gloss powder-coated sheet steel chasis and hood; high-gloss acrylic front, buttons and feet high-gloss nickel-plated or black anodized
Equipment	Foil-shielded high-end power cable
Mains voltage Power consumption	230 V ~ 50 / 60 Hz 76 VA (unloaded) 127 VA (loaded)
Weight	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.

Specifications

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