Looking for 2sb681 + 2sd551 (or analog)

[LinuxGuru]

Hi !

I have broken Sansui G8700DB, and now looking for 2sb681 + 2sd551 transistors (originally Toshiba, but any other respectable company like On Semi is also OK).
I seen them on sale on eBay, and they look like counterfeit. I cannot state it is as fact, but somethings look really suspicious. For example, on original transistors "Toshiba" logo printed in curved italic, on those for sale on eBay - just in plain text. I'm in doubt Toshiba have decided to change logo style, but who really knows ??
Any good and reasonably priced source in Europe is OK. If anyone can suggest analogs in TO3 case, I would be very grateful. 2sb681 / 2sd551 seem to be discontinued, but I do not know substitution part #.

Thanks in advance for any suggestion(s).

 

[glen65]

2SB681 go to MJ21193
2SD551 go to MJ21194

Don't waste time trying to locate original devices.
Chances are you will end up with fakes.

 

[LinuxGuru]

Hi, glen65!

Thanks for suggestion!

I have looked in various sources (of Russian origin), and they listed ECG281, 2SB697, 2SB655A, 2SA679, 2SA1072, 2SB554, 2SB655 as close substitutes of 2SB681.

How did you find this replacement? There is enormous number of different transistors with very close characteristics, and finding close substitute which will preserve great sonics of amplifier is no ordinary task indeed.

 

[glen65]

Hi, glen65!

Thanks for suggestion!

I have looked in various sources (of Russian origin), and they listed ECG281, 2SB697, 2SB655A, 2SA679, 2SA1072, 2SB554, 2SB655 as close substitutes of 2SB681.

How did you find this replacement? There is enormous number of different transistors with very close characteristics, and finding close substitute which will preserve great sonics of amplifier is no ordinary task indeed.

Most all of the techs here have already been using them for some time.
On Semiconductor (formerly Motorola) have a few different numbers that
will actually work fine. But the ones I listed are the most popular.

 

[EchoWars]

How did you find this replacement? There is enormous number of different transistors with very close characteristics, and finding close substitute which will preserve great sonics of amplifier is no ordinary task indeed.

http://www.audiokarma.org/forums/showthread.php?t=214453

Post #8.

Transistors aren't tubes, and characteristics are much less important (generally speaking) to the final sound. The fact that 98% of solid-state output stages are run in a common-collector topology (power gain as opposed to voltage gain, full bandwidth of the output devices available) helps.