Spartacus 300

PURE 300B POWER AMPLIFIER

Spartacus 300 is a statement.
A masterpiece demonstrating how modern thinking applied to Directly Heated Triodes with advanced magnetic materials and a classic concept eclipses all other approaches. It is an engineering overkill in all aspects based on the legendary Western Electric 300B tube. It used six 300B tubes in 2 stages to deliver 50W of pure class A triode sound.

Custom current production tubes for long life
50W for ample power reserves
Low noise for subtle dynamics
Auto bias for compensation of tube ageing and correct operation of any 300B

Current sourced 300B Shunt regulator for stable power allowing explosive dynamics and transparency even on the hardest loads
Transformer input and output for galvanic isolation

Microprocessor controlled operation for safety
Special filament heating circuit for harmonic richness and tube protection
Highest quality torque binding posts protecting your cables

The Spartacus 300 employs Directly Heated Triodes (DHTs) exclusively in its signal path, utilizing only two amplification stages to preserve signal purity and sonic character. To maintain consistency and excellence, we chose a single tube type for this implementation: the legendary 300B.

The input stage features a 300B tube with transformer coupling on both the input and output. The input is a step-up silver/permalloy transformer, which adds gain, while the output is a phase-splitting transformer that drives the output stage. Notably, there are no capacitors in the signal path. While the design appears simple, achieving optimal performance requires extensive auxiliary circuitry to ensure the tube operates at its best, isolated from power supply fluctuations and mechanical vibrations.

The output stage consists of four 300B tubes operating in parallel push-pull configuration, centered around a custom transformer wound on a unique core material and biased in pure Class A. The power supply is based on a shunt regulator design, utilizing yet another 300B tube. This ensures any current imbalance in the output stage passes through the 300B, with no capacitors in the path. The result is instantaneous clipping with no modulation, stable power rails, and virtually no noise. For the first time, you can truly hear what a 300B tube is capable of—prepare to be amazed by its clarity and speed. Complemented by a nano-crystalline choke power supply filter, the Spartacus 300 redefines tube amplification.

Despite its simple signal path—wire-vacuum-wire-vacuum-wire—the Spartacus delivers exceptional performance with zero negative feedback. Each component in the signal path is meticulously selected to be the best for its purpose, achieving both simplicity and excellence.

The 300B tube was chosen for its legendary status, widespread availability, and exceptional linearity. It is one of the most linear amplifying devices ever made and among the finest audio tubes in existence. Triode vacuum tubes like the 300B produce distortion levels orders of magnitude lower than solid-state devices, and the distortion they do generate is primarily a consonant 2nd harmonic. To further minimize distortion, we employ a technique that runs two tubes out of phase, effectively canceling each other’s distortion.

A microprocessor manages the startup sequence and monitors the operation of each tube, ensuring optimal performance. It oversees the regulated power supplies and the auto-bias system, making tube replacement effortless. The modular design allows for easy in-field servicing through module exchange.

The generously sized chassis encloses the tubes for safety and to reduce airborne microphony, while also acting as a giant heatsink.

Look no further—there is no commercially available product that comes close to the Spartacus 300.