Designing a single-ended amplifier based on 6C33S or 6336 tubes presents several unique challenges, particularly when it comes to the output transformer. These tubes are characterized by extremely low internal resistance and very high operating currents, features that require a transformer specifically engineered for this demanding application.
The SE2K-6C33S V3 was developed precisely with this goal in mind: to provide a high-quality single-ended output transformer optimized for a 2Kohm primary impedance, capable of fully exploiting the sonic potential of these remarkable power tubes.
Unlike many generic transformers that are simply adapted to the task, the SE2K-6C33S V3 was specifically designed to handle the substantial DC currents typically required by both the 6C33S and the 6336. The magnetic circuit, air gap dimensioning, and winding arrangement have all been carefully engineered to deliver excellent low-frequency performance without sacrificing high-frequency extension.
The result is an exceptionally wide frequency response of 20Hz to 90kHz within 1dB, a figure that reflects not only the quality of the materials and construction, but also the extensive attention devoted to the transformer’s electromagnetic design.
Particular attention has been paid to minimizing parasitic capacitances and leakage inductance, two critical factors for achieving accurate high-frequency reproduction and fast, natural transient response. This allows the amplifier to maintain an open, detailed sound with excellent transparency and without unwanted coloration.
The V3 version represents the final evolution of a design refined through numerous real-world builds and extensive measurement sessions. Every aspect has been optimized to ensure long-term reliability, operational stability, and consistent performance.
The SE2K-6C33S V3 is particularly well suited for high-performance single-ended amplifiers intended for use with high-efficiency loudspeakers, where the transparency of the output transformer becomes essential for preserving the character of both the tube and the overall circuit.
Like all SB-LAB transformers, the SE2K-6C33S V3 is handcrafted using carefully selected materials, proprietary winding techniques, and individual testing procedures performed on every transformer produced.
Main specifications:
- Model: SE2K-6C33S V3
- Application: single-ended amplifiers using 6C33S and 6336 tubes
- Primary impedance: 2Kohm
- Frequency response: 20Hz – 90kHz (-1dB)
- Optimized design for high anode current operation
- Handcrafted SB-LAB construction
For builders seeking to create a no-compromise single-ended amplifier based on the legendary 6C33S or 6336, the SE2K-6C33S V3 offers a purpose-designed solution developed specifically to reveal the full potential of these extraordinary power tubes. For availability, pricing, or custom requirements, please visit the SB-LAB Contact Page and use the contact form.