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Replacements for 2sc650 and 2sc281

ImNeuman

ImNeuman

New Member
Hello, I'm looking for modern alternatives for a 2sc650 and 2sc281. I cannot find any information online, and I feel like having people's input could help push me in the right direction.

They are used in the amplifier board of a Roberts X1740, which is equivalent to the Akai X-150d.

Any input would be appreciated
 
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ImNeuman said:
cannot find any information online
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Welcome to AK. I have to say that these seem to be as easy to research as it gets. Did you not find these, or do you not find them credible?

https://www.web-bcs.com/transistor/tc/2sc/2SC650.php

https://www.web-bcs.com/transistor/tc/2sc/2SC281.php

I would probably use KSC1845 and KSC1815 (respectively) myself, but that's partly because I have them "in stock". Note that these parts have the base terminal at one end rather than in the middle.

Or you could probably use BC550 in both positions if you wanted base-in-the-middle, but I'm not as familiar with these.
 
The 2SC650 is only 25V (C-E), and the 2SC281 is only 20V, so a BC548C or better would work, along with the suggestions above.
 
chazix said:
Welcome to AK. I have to say that these seem to be as easy to research as it gets. Did you not find these, or do you not find them credible?

https://www.web-bcs.com/transistor/tc/2sc/2SC650.php

https://www.web-bcs.com/transistor/tc/2sc/2SC281.php

I would probably use KSC1845 and KSC1815 (respectively) myself, but that's partly because I have them "in stock". Note that these parts have the base terminal at one end rather than in the middle.

Or you could probably use BC550 in both positions if you wanted base-in-the-middle, but I'm not as familiar with these.
Click to expand...
Thanks for your warm welcome!

I don't have much experience when it comes to transistors so I felt like it would be best to ask people who would know more.
I wouldn't be able to know what to look for when looking for replacements.

In terms of the KSC1845, I happen to have a few spare on hand. I'll see if they work out for me.

Finally, is there an audible difference between the KSC1845, KSC1815, or BC550? Or anything similar?
Thanks
 
ImNeuman said:
Thanks for your warm welcome!

I don't have much experience when it comes to transistors so I felt like it would be best to ask people who would know more.
I wouldn't be able to know what to look for when looking for replacements.

In terms of the KSC1845, I happen to have a few spare on hand. I'll see if they work out for me.

Finally, is there an audible difference between the KSC1845, KSC1815, or BC550? Or anything similar?
Thanks
Click to expand...
I have noticed a huge audible difference between the 1845 and 1815 in a Sansui 9090 tone board, 1815 being much quieter and subdued over the 1845s. I stuck with the original C1313s in the 9090 tone board because both the 1845 and 1815 changed the sound so much in a negative way for my ears. Just my experience with substituting 1845s and 1815s.
 
painttoad said:
why's it on the list?
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I would imagine that in some units, it was run on the ragged edge of its SAO, and as such had a higher than usual failure rate. Much as 2SC1318 is on the list, despite being an excellent, reliable transistor---except in some hot running Pioneer power supplies where is wasn't derated enough and tended to fail a lot. I guess it didn't hold up too badly, as I've seen nearly 50 year old units still working well, and having never been worked on.
 
tarior said:
I would imagine that in some units, it was run on the ragged edge of its SAO, and as such had a higher than usual failure rate. Much as 2SC1318 is on the list, despite being an excellent, reliable transistor---except in some hot running Pioneer power supplies where is wasn't derated enough and tended to fail a lot. I guess it didn't hold up too badly, as I've seen nearly 50 year old units still working well, and having never been worked on.
Click to expand...
fair enough.
 
painttoad said:
2sc1313 are on the shoot on sight list, i would not leave them personally. your gear though.
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I had originally replaced them with 1845s but the warm, clear sansui sound was lost and it just sounded harsh, high frequencies were really harsh. Putting the 2SC1313s back in brought back the amazing Sansui sound. It was weird, maybe my hearing is just very sensitive, but I really like the sound quality out of the 1313's. This was the result in both an 8080 and a 9090 I restored, identical sound change with 1845s.
 
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