Product Overview
The Toshiba 2SA679/2SC1079 transistor pair represents a classic combination of complementary power transistors specifically designed for high-fidelity audio amplifier applications. These silicon transistors in TO-3 packages offer exceptional power handling capabilities and reliability, making them ideal for professional audio equipment and high-end consumer electronics.
Technical Specifications
| Parameter | 2SA679 (PNP) | 2SC1079 (NPN) | Unit |
| Material | Silicon (Si) | - |
| Polarity | PNP | NPN | - |
| Package | TO-3 | - |
| Max Collector Power Dissipation (Pc) | 100 | 100 | W |
| Max Collector-Base Voltage (Vcb) | 110 | 150 | V |
| Max Collector-Emitter Voltage (Vce) | 110 | 150 | V |
| Max Emitter-Base Voltage (Veb) | 5 | 5 | V |
| Max Collector Current (Ic) | 8 | 15 | A |
| Current Gain (hFE) | 40-140 | 40-140 | - |
| Transition Frequency (fT) | 10 | 10 | MHz |
Key Features and Applications
Primary Features:
-
High Power Dissipation: 100W maximum power handling capability
-
Complementary Pair: Perfectly matched PNP and NPN transistors
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TO-3 Package: Robust metal package for excellent thermal performance
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High Current Capability: Up to 15A collector current for 2SC1079
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Excellent Linearity: Ideal for high-fidelity audio applications
Typical Applications:
- High-power audio amplifiers
- Professional audio equipment
- Home theater systems
- Guitar amplifiers
- Public address systems
- Studio monitoring equipment
Replacement and Equivalent Transistors
When sourcing replacements for the 2SA679/2SC1079 pair, it's crucial to ensure compatibility. The original Toshiba 2SA679/2SC1079 pair offers the best performance and reliability. However, some commonly used replacements include:
| Original | Replacement Options | Notes |
| 2SC1079 (NPN) | Sanken 2SC1116A, MJ15024 | Ensure proper heat sinking |
| 2SA679 (PNP) | Sanken 2SA1115A, MJ15025 | Check pin compatibility |
Frequently Asked Questions
What is the main application of 2SA679/2SC1079 transistors?
These transistors are primarily used in high-power audio amplifier output stages, particularly in complementary symmetry configurations for push-pull amplifier designs.
Are these transistors still manufactured by Toshiba?
While original Toshiba production may have ceased, high-quality reproductions and NOS (New Old Stock) units are available through authorized distributors like Koeed Electronics.
What is the maximum operating temperature?
The TO-3 package allows for excellent thermal performance, with maximum junction temperature typically around 150°C when properly heat-sinked.
Can I use these transistors in switching applications?
While primarily designed for linear audio applications, they can be used in switching circuits, though their transition frequency of 10MHz may limit high-frequency performance.
How do I ensure proper installation?
Always use appropriate heat sinking, thermal compound, and follow proper mounting procedures for TO-3 packages. Ensure electrical isolation where required.
Technical References and Trust Metrics
Industry Recognition: The 2SA679/2SC1079 pair has been widely used in professional audio equipment from manufacturers like Pioneer, particularly in models such as the Pioneer SA-9900 amplifier.
Quality Assurance: When purchasing the 2SA679/2SC1079 transistor pair, ensure you receive genuine components with proper packaging and documentation.
Technical Documentation: Always refer to the official datasheets for detailed specifications and application notes when designing circuits using these transistors.
Conclusion
The Toshiba 2SA679/2SC1079 transistor pair remains a benchmark for high-performance audio power transistors. Their robust TO-3 packaging, high power handling capabilities, and excellent linearity make them ideal for demanding audio applications. Whether you're restoring vintage audio equipment or designing new high-fidelity amplifiers, the authentic 2SA679/2SC1079 pair delivers the reliability and performance that audio professionals demand.