C1124 Transistor Datasheet Better Jun 2026

1.2 W (Ambient) up to 20 W with a heatsink (TO-126 package)

: A higher-voltage (300V) NPN transistor that is widely available. In a Sansui AU-9500 restoration, a technician considered using KSC3503/KSA1381 as a substitute, noting that while the originals were 1A parts, the KSC3503 is a 0.1A part. The discussion concluded that in the pre-driver position, the actual current demands are likely around 100mA, meaning the KSC3503 would be perfectly safe and a very high-quality replacement.

The 2SC1124 is an .

| Replacement | Why it works | Caveat | | :--- | :--- | :--- | | | Excellent low-noise RF replacement. Same TO-126. | Slightly lower fT (200MHz), fine for audio/IF. | | BF420 | Cheap and available. | Lower Vceo (40V). Check your circuit voltage. | | 2SC3423 | Identical specs, same era. | Also obsolete. Only if you have spares. | | MPSH10 | Better for VHF oscillators (>200MHz). | Different package (TO-92). Use leads. | c1124 transistor datasheet better

The C1124 transistor is typically housed in a (or elongated TO-92) plastic package. This package is slightly taller than a standard TO-92 to allow for better heat dissipation up to its 1-watt limit.

Hitachi, Matsushita (Panasonic), or Sanyo (depending on the lot) Package: TO-220 (isolated or non-isolated) Type: NPN, Power Switching

The 2SC1124 is generally housed in a modified or TO-92L package (longer body for better heat dissipation). The 2SC1124 is an

| Replacement | Why It Is Better | Better Spec | | :--- | :--- | :--- | | | Readily available, cheap, TO-220 | ( V_CEO ) 100V (higher), 3A, 40W | | 2N6124 | Better heat dissipation | 4A, ( h_FE ) linear up to 3A | | BD243C | High gain at low current | ( h_FE ) 40-250, excellent for audio | | MJE340 | High voltage safety margin | ( V_CEO ) 300V, 20W, stable | | KSD880 (Original Japanese) | Direct pin-for-pin replacement | Same case, slightly lower saturation |

: Authentic components use a solid TO-202/TO-220 physical architecture with a flat metal backing plate. Avoid any components shipped in standard, all-plastic TO-92 packages claiming to be the C1124.

Drives the cathode-ray tube (CRT) electron guns, requiring rapid voltage swings across a 150V rail. | Slightly lower fT (200MHz), fine for audio/IF

The 2SC1124 is commonly found in the or TO-220 package. When facing the front (labeled side) with pins pointing downward, the standard pinout is: Base (Left) Collector (Center/Metal Tab)

Because original Sony or Sanyo C1124 components are out of production, technicians frequently require modern substitutes. To find a replacement that performs as well as or better than the original, focus on matching the 140V collector rating and the

When analyzing a datasheet for the C1124, you need to focus on the "Absolute Maximum Ratings" to ensure safe operation. If you are repairing a circuit, these are the numbers you cannot exceed.