Yamaha TA-30 Transistors

[dmeek]

I'm working on an old TA-30, seems to be an earlier version than the schematics that are available, ser #20049 pcb #LC-0400-2.
I'm curious about the transistors, I can't find data anywhere. they are all NPN silicon so I will try some substitutions until I find one that works.
Does anyone know anything about these? I'm not sure C401 is short for 2SC401. 25 H ?

https://music-electronics-forum.com/...1&d=1580494191

[g1]

Not sure what you have for schems., so posting all info I have.

[dmeek]

Thanks g1, I have those and other old Yamaha schematics. No luck. Looking in some of my old books it looks like the C401 is indeed 2SC401 made by Sony. There is also a
2SC293 on the board, a TO5 marked Sony on top, so I'll assume the 25 H is Sony also.

[Enzo]

Looks like small signal circuits with basic NPN xstrs. Most anything should work there.

[dmeek]

On the newer version schematic they use 2SC373 in place of the 25H. I ended up using 2SC1000. The 25H was making a lot of noise. Now on to fixing the tremolo and reverb

[drewl]

Most of the old Japan made amps have small signal transistors with ECB pinout as opposed to EBC.

So double check your pinouts.

[dmeek]

The leads on these are flat. I'd like to see the datasheet but that seems highly unlikely


https://music-electronics-forum.com/...1&d=1580590400