Looking for a particular transistor

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1

Hi all,

I am looking for a particular transistor to replace a dead one in my stereo receiver. The receiver is probably close to 30 years old, so as one might expect I am having trouble a) identifying the exact specs of the transistor, and b) finding a suitable replacement. I’ve attached a picture of it (the problem one is the one on the right marked ‘JAPAN B1548’). I’ve tried searching for this specific transistor but I can’t seem to find an exact match, and I don’t know it’s specs so I am not sure of how to find a modern replacement.

I would really appreciate anyone’s thoughts or recommendations - I’m posting on digikey as I thought they might be the most likely company/source that would have a similar transistor and also willing to sell these in limited numbers.

Thank you so much,

Cookies

IMG_20260216_205548343_HDR
IMG_20260216_205548343_HDR1920×2560 942 KB

2

Hello @Cookies42,

This Japan series of transistor often uses a shortcut where they leave off the 2S prefix.

  • We are looking at a 2SB1548. Unfortunately, it is listed as obsolete. A candidate substitution is the MJF2995G.

  • The 2SD2374 is also listed as obsolete A candidate substitution is the MFJ3055G.

Be sure to verify my work against datasheet parameters. Check electrical as well as mechanical e.g., pin orientation.

Happy soldering,

APDahlen

P.S. There are differences such as gain bandwidth product. This shouldn’t be an issue at audio frequency as most designs are rock solid and can accept a range of transistors. But there is no truth like an installed part working in the equipment.