Japanese transistor and diode cross reference

[Bob M.]

Hi all,

I'm trying to get a little better at repairing solid state amps and a friend gave me a non-working transistor amp to kinda practice on.

It's going ok but I'm having trouble with cross referencing the diodes and transistors to US equivalents or getting information on the same.

The amp was manufactured in Japan, using all Japanese parts but with the name of a US amp maker on the front, as is the trend now with offshore manufacturing for lower end items.

The code/nomenclature printed on the transistors appears to be JIS codes (Japan Industrial Standard) as opposed to the US JEDEC.

It would be great if there was a book/website that listed all Japanese transistor/diodes with type (bipolar, FET, etc), polarity (NPN or PNP), specifications, US equivalent and pinout (which leads are collector, base and emitter or source, gate, drain, as the case may be).

This is where I'm stuck. Especially with diodes where there are far few parameters, I'm surprised that there is not an exact equivalency chart somewhere. But I'll assume I've been looking in the wrong places. Any help is appreciated. I'd really hate to waste my time looking for obscure Japanese semiconductors if there were readily available US equivalents (at a fraction of the cost).

Thanks,
Bob M.

[dmeek]

Before the internet age one of my most prized books was the Towers International Transistor Selector. There were others in the series for FETs , Op-Amps, Digital ICs etc.
My copy is a little out-of-date (1992), though still useful sometimes. Here's a PDF of the 1974 version:

https://archive.org/details/TowersIn...sistorSelector

[Enzo]

There are no direct replacement JEDEC types for the Japanese parts. There are electrical equivalents, but the pinouts of the bases will be different.

Diodes? Well, there are basic rectifiers like 1N4007. There are "switching diodes" like 1N4148 or 1N914. Then there are zener diodes which come in specific voltages and also half watt, 1 watt, 5watt. There are Japanese types similar, but in almost every case, one of my US types will work fine. I buy 1N4148 by the 100 lot.

I have a couple Japanese transistor manuals. Numerical;; listing of transistors with specs in chart form. I used to use it a lot. But any more if I want to know a part, I just enter its number into google.

The common TO92 case across the front for 2Nxxxx or MPSAxxx types is EBC. The 2S series are all ECB. I am not aware of exceptions, though there could be a small few. All the larger types like TO3, TO220, TO39 are the same in both systems.


You are talking guitar amps. Well those are about as low tech as it gets. The little diodes like they use for clipping or in channel switching, a 1N4148 will work fine. Other transistors, well, basically meet the specs of the target device, and it will likely work.

[g1]

Are you putting '2S' in front of the letters when looking for data on the transistors? It is supposed to be 'understood' and is usually omitted in the labeling.
For example, a marking of D313 would actually be a 2SD313.

[mozz]

Not all Japanese small transistor 2s series are pinout ecb. If you're gonna work on a lot of transistor stuff, get a Peak DCA 55.

[Enzo]

Tell me a Japanese TO-92 that is not ecb, and I will make a note of it.

[mozz]

Tell me a Japanese TO-92 that is not ecb, and I will make a note of it.

Thought you were retired?

Generally, any round japanese transistor is not ecb. I have some 2sc458, original, used in many tape decks, they are not ecb. In my Sams transistor spec manual, i can see many that are not ecb, the lead identification number goes to a chart for all that. Maybe all modern, 2sc1815, 2sc945, follow that rule but many many older type do not.

[Enzo]

If those are TO92, I stand corrected.

[The Dude]

"Generally, any round japanese transistor is not ecb"

I think he's referring to the older TO18 and TO39 transistors. I think all of the Japanese TO92 are indeed ECB.

[Enzo]

OK, I did specify TO92.

[dmeek]

Here's one 2SA709:

https://music-electronics-forum.com/...1&d=1559921501

And going the other way 2N3704:

https://music-electronics-forum.com/...1&d=1559921501

[Enzo]

Again, I stand corrected. Thanks.

[mozz]

One rule of thumb is 2sa and 2sb were all PNP, I think so.

[g1]

And C & D are NPN.

[dmeek]

Actually you were correct

The 2S series are all ECB. I am not aware of exceptions, though there could be a small few.

.

There is also 2SA708 and the compliments 2SC1008 and 2SC1009. I vaguely remember seeing these as drivers in a hi-fi stereo amp long ago.