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.

I present my latest product dedicated to HiFi enthusiasts: the audio output transformer model SE6K4-46. Specifically designed for the type 46 tube, this transformer represents a union of tradition and innovation, delivering uncompromising musical quality.

Technical Specifications of the SE6K4-46

The SE6K4-46 is a single ended transformer with extraordinary characteristics, designed to fully exploit the potential of the type 46 tube:

• Primary impedance: 6400 ohm
• Secondary impedance: 8 ohm
• Nominal power: 1.25 Watt RMS
• Frequency response:
  • 10 Hz at -0.2 dB
  • 60 kHz at -1 dB

Thanks to these specifications, the SE6K4-46 ensures faithful and detailed music reproduction, enhancing every sonic nuance.

The Type 46 Tube: A Dive into History

The 46 tube is a true vintage gem, highly appreciated by audiophiles for its unique characteristics. It is a dual-grid audio amplifier of American production, introduced to the market in 1933. Here are some technical and historical curiosities:

• Operational versatility:
  • In class B configuration, with both grids connected together.
  • In class A configuration, with the outer grid connected to the anode.
• Historical use: An interesting example is the Silvertone 1654, a 1933 audio set that used three 46 tubes in the audio stage, following datasheet recommendations of the time: a class A driver feeding a pair of class B tubes.

This tube not only represents a piece of audio electronics history but also provides an exceptionally high musical quality, ideal for sound purists.

Performance and Quality of the SE6K4-46

The SE6K4-46 transformer was developed to ensure excellent performance in every situation, with an exceptionally wide frequency response ranging from 10 Hz (-0.2 dB) to 60 kHz (-1 dB). This result was achieved thanks to careful design and the use of high-quality materials, ensuring clear, dynamic, and faithful sound reproduction.

Who It Is For

This transformer is dedicated to lovers of the 46 tube, an ideal choice for those seeking unmatched musical quality and who want to highlight every sonic detail. With the SE6K4-46, it is possible to explore new sound dimensions, rediscovering the pleasure of listening to music with an authentic and refined single ended system.

Conclusion

The SE6K4-46 is more than just a component: it is a tribute to the history of high fidelity and an invitation to experience the purity of tube sound. Discover how this transformer can transform your listening experience and elevate your passion for HiFi to a new level. If you are interested in purchasing, contact me!

The SE8K5-6V6P single ended audio output transformer is designed to enhance the performance of 6V6 tubes in pentode configuration. With a primary impedance of 8500 ohm and secondary outputs at 6/8 ohm, this transformer delivers a manageable and achievable power of 3.5 watts.

Main Features:

• 6V6 Tube Compatibility: Optimized for use with 6V6 tubes in pentode configuration, the SE8K5-6V6P transformer offers superior audio performance and outstanding sound fidelity.
• Power and Versatility: With a power handling of 3.5 watts, this transformer is ideal for audio projects requiring adequate power and high-quality sound reproduction.

Hands-On Experience:

To learn more about the 6V6 tube specifications and biasing, refer to the tube datasheet screenshot included in this article. Additionally, explore photos of the prototype build and the test bench circuit for a more complete overview of the SE8K5-6V6P transformer’s performance.

Explore Other Transformers: If you are interested in additional options for 6V6 tubes, visit the page of our other single ended output transformer designed for 6V6 tubes in triode configuration by clicking here.

When purchasing output transformers together with other components such as chokes or power transformers, you can benefit from significant quantity discounts compared to unit prices. Check the discount rates below.

Model SE8K5-6V6P
	Type: Single Ended Compatible with tubes: 6V6/6V6G/6V6GT (*) Primary impedance: 8500 ohm Secondary impedances: 6/8 ohm Primary resistance: 399 ohm MAX Power: 3.5 Watt RMS Leakage inductance: 34 mH Frequency response: 18 Hz ~ 28 kHz -1 dB (*) It can also be used with other tubes.
	Dimensions (mm) L 66 H 80 S 83 F 51 F2 45

Dimensions caption