replacing 2SK78 fet in a Yamaha preamp

Nigel Goodwin said:

As I said a long time back - junk the stupid idea, and build a decent preamp in the same box with the same facilities.

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unclejed613 said:

that depends on if you only want a functional preamp, or if you plan to some day sell it to a collector... Yamaha audio equipment seems to be very collectible, especially anything before 1990 vintage.

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Arno1 said:

Hi everyone,
Sorry to bring this old thread back but I'm facing the exact same situation here.
I'm having the hardest time finding a proper match for 2SK78C transistor that fried on a Yamaha C1 pre amp.
The one shown on the attached picture.
Did you end up finding a good replacement for this one?
Thank you for any help you could bring!!
Greetings from France!!

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vtech said:

I happened to be involved with Yamaha Audio at the time ...
2SK78/2SJ24 were made by Yamaha utilizing the SVJ technology and were exclusive to some of the their Home Audio products during the "low noise" contest era.
There were couple of packages(T092, T05) along with A/B/C suffixes which mainly changed the power dissipation.
View attachment 133982View attachment 133983

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