If you cannot find the exact D998/B778 pair, you can consider these substitutes, but always verify the pinout and physical package size (TO-3P/TO-3PF) before installation: Transistor D998 - Mercado Libre
| Test | Red Probe | Black Probe | Expected Reading | | :--- | :--- | :--- | :--- | | NPN (D998) B-E | Base | Emitter | 0.5–0.7V | | NPN (D998) B-C | Base | Collector | 0.5–0.7V | | PNP (B778) E-B | Emitter | Base | 0.5–0.7V | | PNP (B778) C-B | Collector | Base | 0.5–0.7V | Persamaan Transistor D998 B778
After replacement, always re-adjust the quiescent current (idle bias) per the amplifier’s service manual to prevent thermal runaway. If you cannot find the exact D998/B778 pair,
: Ini adalah versi manufaktur lain (biasanya dari KEC) dengan spesifikasi yang identik. Panduan Memilih Pengganti Motor Control The are robust audio output transistors,
: Used in voltage regulator circuits due to their 120V breakdown rating. Motor Control
The are robust audio output transistors, but due to obsolescence, the best persamaan for most applications is the 2SC5200 (NPN) and 2SA1943 (PNP) pair from Toshiba (or equivalent brands like KEC, Fairchild/Onsemi). For higher-voltage or professional amps, use MJL4281A/MJL4302A . Always replace both channels with the same matched pair and verify your amplifier’s rail voltage before substituting.
Keduanya memiliki rating yang hampir identik namun dengan polaritas yang berbeda: D998 (NPN) dan B778 (PNP). Tegangan Maksimum (VCEO): 120V. Arus Kolektor Kontinu (IC): 10A. Disipasi Daya (PC): 80W (pada suhu casing 25∘C25 raised to the composed with power cap C Penguatan Arus (hFE): Sekitar 55 hingga 160. Kemasan (Package): Umumnya TO-3P atau TO-3PML. Persamaan (Equivalent)