The **S-246-R** is a specific model of an **Audio Output Transformer** typically used in high-fidelity (Hi-Fi) tube amplifiers or professional audio equipment. These components are designed to match the impedance between high-impedance vacuum tube circuits and low-impedance loudspeakers. --- ### 1. Technical Specifications The following table outlines the typical electrical characteristics for a high-quality output transformer in this series: | Feature | Specification | | :--- | :--- | | **Component Type** | Audio Output Transformer | | **Primary Impedance** | Usually ~5kΩ to 8kΩ (Center Tapped) | | **Secondary Impedance** | 4Ω, 8Ω, or 16Ω (Selectable) | | **Frequency Response** | 20Hz – 20kHz (±1dB) | | **Max Power Output** | Varies by size (typically 15W - 30W) | | **Core Material** | Silicon Steel / Oriented Core | --- ### 2. Key Electronic Functions The S-246-R performs three critical roles within a circuit: 1. **Impedance Matching:** Vacuum tubes operate at high voltages and low currents (high impedance). Speakers require low voltage and high current (low impedance). The transformer bridges this gap using a specific turns ratio. 2. **DC Isolation:** It prevents the high-voltage Direct Current (DC) plate voltage of the vacuum tube from reaching the speaker, which would otherwise destroy the speaker coil. 3. **Signal Phase Inversion (Push-Pull):** If used in a "Push-Pull" configuration, the center-tapped primary allows two tubes to work in tandem to amplify the signal more efficiently. --- ### 3. Wiring Diagram Concept Below is a simplified representation of how the terminals are typically configured: ```mermaid graph LR A[Tube Plate 1] --> B(Primary Start) C[B+ High Voltage] --> D(Primary Center Tap) E[Tube Plate 2] --> F(Primary End) G(Secondary Com) --> H[Speaker -] I(Secondary 8 Ohm) --> J[Speaker +] ``` --- ### 4. Common Applications * **Tube Guitar Amplifiers:** Used to provide the "warm" saturation characteristic of vintage amps. * **Hi-Fi Stereo Amps:** Used in single-ended or push-pull class A/AB designs. * **Restoration:** Often used as a replacement part for vintage radio or audio gear requiring specific "R-core" or "EI-core" footprints.