Thrax SPARTACUS 300
The Thrax SPARTACUS 300 pursues the spellbinding immediacy of pure 300B triode sound with 50 watts of Class A authority. Its six-tube, capacitor-free architecture, zero-feedback signal path, and nanocrystalline magnetics aim for vivid harmonic richness and exceptional directness. Best of High End regards this lavishly engineered design as a genuine redefinition of tube amplification.
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Nicely Roasted
Sound Quality
82/100
Build Quality
91/100
Value for Money
85/100
Pros
Authentic, harmonically rich 300B presentation with 50W of pure Class A triode output.
Exceptionally ambitious construction, including nanocrystalline-core transformers and choke-based power supply.
Ultra-simple, capacitor-free and zero-feedback signal path supports a highly direct presentation.
Cons
Available review coverage offers little direct evidence on bass grip, dynamics, imaging, or performance with difficult loudspeaker loads.
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What Reviewers Are Saying
SOUND QUALITY PERFORMANCE 82/100
The available coverage is enthusiastically positive about the amplifier’s pure 300B presentation and unusually direct signal path. It offers little detailed listening commentary on resolution, bass control, or spatial performance, so the finer aspects of its sound remain less fully documented.
Transparency Resolution
81/100
The review describes the Spartacus as revealing what a 300B can really sound like and calls the result amazing. However, it gives no specific listening examples concerning fine detail, low-level retrieval, background silence, or freedom from grain.
Tonal Balance Musicality
88/100
The strongest praise concerns its “pure class A triode sound” and the promise of an authentic 300B experience. That points to a highly appealing, harmonically rich presentation, though the review does not discuss tonal balance across different recordings or speakers.
Dynamics
80/100
The 50W Class A, parallel push-pull 300B output stage suggests meaningful capability for a triode design. Still, the review provides no direct observations about transient impact, bass grip, loud-level ease, or behavior with difficult speaker loads.
Soundstage Imaging
79/100
The review does not offer direct comments on image focus, stage width, depth, or layering. Its enthusiasm for the amplifier’s purity is encouraging, but spatial performance is not specifically described.
Assessments of Build Quality, Usability, and Overall Propositions.
Build Quality
91/100
The review characterizes the Spartacus as engineering overkill, highlighting its nanocrystalline-core output transformers, choke-based power supply, and carefully selected signal-path parts. Its transformer-coupled, capacitor-free architecture, regulated supply, sealed chassis, auto-bias control, and modular serviceability indicate unusually comprehensive execution.
Value for Money
85/100
At roughly 71,000–90,000 in the stated price range, the Spartacus is positioned firmly as a no-compromise specialist amplifier. The available review celebrates its engineering and performance but does not compare its asking price with competing high-end tube amplifiers or directly assess value.
Reviews & Sources
Professional reviews and sources for this product's Watt'n Potatoes analysis.
Online Reviews & Mentions
YouTube Reviews
Forum Mentions
No forum mentions found yet
Specifications
- Weight
- 55kg
- Dimensions
- 430x650x300mm
- Power
- 380W 115/230V 50/60Hz
- Max. input level
- 4Vrms
- Output Power
- 50W
- Gain
- +16db
- Input impedance
- 1.5k Ohm
- Output impedance
- 0.5 Ohm
- Signal to Noise
- 112db
- Frequency response
- 20-20,000Hz +/- 1db
- THD @1W
- 0.05%
- Specification
- Exclusive use of 300B tubes for consistent, captivating sound.
- Specification
- Two-stage amplification with transformer-coupled input and output for maximum fidelity.
- Specification
- No capacitors in the signal path—just pure, uncolored sound.
- Specification
- Parallel push-pull output stage with custom transformer for 50 watts of Class A power.
- Specification
- Shunt regulator power supply with 300B tube for stable, noise-free operation.
- Specification
- Auto-bias system and microprocessor control for ease of use and reliability.
- Specification
- Special filament heating circuit for harmonic richness and tube protection.
- Specification
- Modular design for easy in-field servicing and upgrades.
- Specification
- Sealed chassis for safety, reduced microphony, and thermal management.
Manufacturer's Description — Thrax
The Spartacus 300 is not just an amplifier—it’s a celebration of the legendary 300B tube, reimagined for the modern era. Combining the timeless warmth of Directly Heated Triodes (DHTs) with cutting-edge engineering, the Spartacus 300 delivers a listening experience that is both powerful and pure. With its minimalist signal path, innovative power supply, and meticulous craftsmanship, it stands as a testament to what tube amplification can achieve.
The Legendary 300B Tube, Perfected
At the heart of the Spartacus 300 lies the 300B tube, renowned for its exceptional linearity and harmonic richness. This iconic tube is used exclusively throughout the amplifier, ensuring a consistent and captivating sonic character. The Spartacus 300 employs only two amplification stages, preserving signal purity and delivering a sound that is both transparent and emotionally engaging.
Minimalist Signal Path, Maximum Fidelity
The Spartacus 300 features a transformer-coupled input and output, with no capacitors in the signal path. The input stage uses a silver/permalloy step-up transformer to add gain, while the output stage is driven by a phase-splitting transformer. This design ensures that the signal remains pure, free from the coloration and distortion often introduced by capacitors.
The output stage consists of four 300B tubes operating in a parallel push-pull configuration, centered around a custom transformer wound on a unique core material. Biased in pure Class A, this configuration delivers 50 watts of power with exceptional clarity and control, even on the most demanding loads.
Innovative Power Supply for Explosive Dynamics
The Spartacus 300’s power supply is a masterpiece of engineering. Based on a shunt regulator design, it utilizes another 300B tube to ensure stable power rails and instantaneous clipping with no modulation. This design allows the amplifier to deliver explosive dynamics and transparency, even under the most challenging conditions.
A nano-crystalline choke power supply filter further enhances performance, reducing noise and ensuring that the amplifier operates at its absolute best. The result is a level of clarity and speed that redefines what a 300B tube can achieve.
Auto-Bias and Microprocessor Control
The Spartacus 300 is designed for ease of use and reliability. A microprocessor manages the startup sequence, monitors tube operation, and oversees the regulated power supplies. The auto-bias systemcompensates for tube aging and ensures correct operation with any 300B tube, making tube replacement effortless.
Harmonic Richness and Tube Protection
A special filament heating circuit not only enhances the harmonic richness of the 300B tubes but also protects them, ensuring long life and consistent performance. Combined with the modular design, which allows for easy in-field servicing, the Spartacus 300 is built to last.
Safety and Stability
The Spartacus 300’s generously sized chassis encloses the tubes for safety and reduces airborne microphony. It also acts as a giant heatsink, ensuring optimal thermal performance. The amplifier’s torque binding posts provide secure connections, protecting your cables and ensuring the best possible signal transfer.
A New Benchmark in Tube Amplification
The Spartacus 300 is more than just an amplifier—it’s a revelation. Its combination of minimalist design, innovative engineering, and the legendary 300B tube delivers a sound that is both powerful and pure. Whether you’re listening to delicate acoustic passages or powerful orchestral crescendos, the Spartacus 300 brings your music to life with unparalleled clarity and emotion.
Experience the Spartacus 300
The Spartacus 300 is not just an amplifier—it’s a gateway to a new level of musical enjoyment. Its combination of timeless tube technology and modern engineering makes it the ultimate choice for those who demand the best.
Discover the power, purity, and passion of the Spartacus 300—and hear your music like never before.
Verified Dealers
Online Dealers
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Authorized dealers for Thrax SPARTACUS 300
- 3mA Audio — online and in-store — Houston, Texas, United States (website)
- Ana Mighty Sound — online and in-store — Paris, Île-de-France, France (website)
- BELHIFI — online and in-store — Meise, Vlaams Gewest, Belgium (website)
- Cake Audio — in-store — San Clemente, California, United States (website)
- Design Audio — in-store — Aix en Provence, Île-de-France, France (website)
- Dr Vinyl — in-store — Middle River, Maryland, United States (website)
- Dream Audio Components — online and in-store — Dunaharaszti, Hungary (website)
- Madformusic — in-store — Arese, Lombardia, Italy (website)
- Rhapsody — in-store — Ravenstein, Noord-Brabant, Netherlands (website)
- Stellar Home Audio — in-store — Commack, New York, United States (website)
and 3 more verified dealers