The D998 (2SD998) and B778 (2SB778) are high-power silicon transistors typically used as a complementary pair in audio amplifier output stages. In this setup, the NPN-type D998 handles the positive half-cycle of the audio signal, while the PNP-type B778 handles the negative half-cycle, a configuration commonly known as a push-pull or Class AB amplifier. Technical Specifications
Transistor 2SD998 (D998) and 2SB778 (B778) are a popular complementary pair of silicon bipolar junction transistors (BJTs) specifically designed for high-power audio frequency amplifier output stages, typically in the 45W–50W range. Transistor Specifications
Dihubungkan ke jalur speaker melalui resistor kapur (biasanya 0.22 atau 0.47 Ohm 5W). persamaan transistor d998 b778 install
Both transistors share the same pin configuration when looking at the front (labeled side) with pins pointing down: Pin 1 (Left): Base (B)
Circuit Biasing: After installation, the bias resistor may need adjustment to ensure the signal is crisp and free of humming or weak output. The D998 (2SD998) and B778 (2SB778) are high-power
package, designed for efficient heat dissipation in power-heavy circuits. AliExpress 2SD998 (NPN) 2SB778 (PNP) Max Collector-Emitter Voltage ( cap V sub cap C cap E cap O end-sub Max Collector Current ( cap I sub cap C Collector Power Dissipation ( cap P sub cap C Current Gain ( h sub cap F cap E end-sub 55 – 160 55 – 160 Application 45–50W Audio Output Stage 45–50W Audio Output Stage Persamaan (Equivalent Replacement)
If you are in a pinch, these work, but they are generally "slower" (lower fT) than the D998/B778. Pros: Cheap and easy to find. typically in the 45W–50W range .
: These are the most common "upgrades." They are rated for higher power (150W) and higher voltage (230V), making them much more robust than the original D998/B778 pair.
These transistors are complementary (NPN and PNP) power audio transistors commonly used in high-fidelity audio power amplifiers.