THÖRESS SE 300B Mono Power Amplifier (Pair)

The THÖRESS SE-300B Mono Power Amplifier is a purist's dream, meticulously engineered to extract the definitive performance from the world's most famous filamentary power triode: the 300B. Operating in pure Single-Ended Class-A mode with zero negative feedback, these monoblocks offer 10 Watts of output power that belies the numbers, delivering a soundstage of immense depth, fluid dynamics, and startling realism. While many 300B amplifiers sound "soft" or overly romantic, the THÖRESS implementation is powerful and resolute. This is achieved through a unique single-stage driver circuit utilizing EL822 pentodes in triode mode and custom in-house C-Core output transformers, ensuring that the amplifier grips the loudspeaker with authority while preserving the magical midrange texture that makes the 300B legendary.

Key Features:

• Pure Single-Ended Class-A: Delivers 10 Watts of unadulterated Class-A power using the classic 300B filamentary triode for ultimate linearity and harmonic richness.
• Powerful Driver Stage: Features a robust single-stage driver tailored around two EL822 (CV2382) power pentodes operated in triode mode at high idle current.
• In-House C-Core Transformers: Equipped with proprietary tape-wound cut core (C-core) output transformers, manufactured in-house to meet the highest possible standards.
• Zero Global Feedback: Employs a minimalist schematic with absolutely no global feedback, preserving the natural phase integrity and micro-dynamics of the signal.
• DC Heated 300B: The 300B tube is DC heated with a cathode balance adjustment potentiometer to eliminate residual hum for a pitch-black background.
• Point-to-Point Wiring: Built entirely by hand in Germany using meticulous point-to-point wiring techniques for superior reliability and signal purity.

Redefining the 300B Sound

The 300B tube is often associated with a "lush" but potentially loose sound. Reinhard Thöress challenges this convention by pairing the tube with an extraordinarily powerful driver stage. By using two EL822/CV2382 power pentodes (wired in triode mode) to drive the 300B, the amplifier ensures the output tube is fully modulated with ample headroom. This results in a sonic presentation that retains the warmth and "glow" of the 300B but adds unexpected dynamic slam, speed, and bass definition.

The C-Core Advantage

The soul of any single-ended amplifier lies in its output transformer. THÖRESS produces these critical components in-house using high-grade tape-wound cut cores (C-cores). Unlike standard EI cores, C-cores allow for tighter winding and superior magnetic flux handling. This results in wider bandwidth and lower distortion, enabling the SE-300B to drive 4, 8, or 16-ohm loads with a level of transparency and control that is rare in the world of low-power tube amps.

Noise-Free Operation

To ensure compatibility with high-efficiency loudspeakers (horns, full-range drivers), the SE-300B is designed for ultra-low noise. The 300B filament is DC heated, and a rear-mounted rotary potentiometer allows for precise balancing of the cathode point to nullify any hum. Additionally, the amplifier is designed with moderate gain (low input sensitivity), which prevents "hiss" issues common in high-sensitivity systems and allows for finer volume control range on your preamplifier.

Handcrafted in Germany

Each monoblock is a testament to functional industrial art. The chassis is constructed from non-magnetic aluminum, powder-coated in the distinctive THÖRESS grey, with anodized printing. Internally, the construction is entirely point-to-point, utilizing high-grade foil-in-oil capacitors produced in Germany. From the hand-wound mains transformers to the vibration-isolated mounting, every detail is considered for longevity and sonic purity.

The Listening Room Difference

We’re a third-generation family business with a brick-and-mortar showroom in Chestertown, Maryland, and a reputation built on trust, not hype. Whether you’re visiting in person or ordering online, we bring decades of experience, personalized service, and honest guidance to every interaction. We don’t just ship boxes. We help build systems, answer your questions like real humans, and make sure every detail of your setup is right, from the cables to the final connection. Our passion is helping you get the most out of your gear, with support that lasts well beyond the sale.

Specifications