Hi. Lately i’m working on an old synth and just for test purposes i’m trying to replace some old transistors. Ordered them from china (they will be with me here in Greece in a couple of months) but i may have a chance to find equivalents locally too.
-The “very” odd ones are the k81 ones. I assume they are similar to 2sk81.
Can’t find any info regarding their pinout in english.
Are they jfet, n channel fet, mosfet, or what?
Some people say that they are close to the j113, with different pinout. What is their type and what is their pinout? Is j113 a correct equivalent, or is there anything other equally mainstream more suitable? Any idea?
-i also look for 2sc2785 equivalents. Similar sources said that bc546 is a good equivalent, with just different pinout. Is this correct? Anything more suitable, equally easy to find?
- And lastly there is a 2sa1175 (as a muting switch i guess). Same sources suggested bc556. Is it ok? Better equivalent that can be found as easily?
Thanks in advance
-The “very” odd ones are the k81 ones. I assume they are similar to 2sk81.
Can’t find any info regarding their pinout in english.
Are they jfet, n channel fet, mosfet, or what?
Some people say that they are close to the j113, with different pinout. What is their type and what is their pinout? Is j113 a correct equivalent, or is there anything other equally mainstream more suitable? Any idea?
-i also look for 2sc2785 equivalents. Similar sources said that bc546 is a good equivalent, with just different pinout. Is this correct? Anything more suitable, equally easy to find?
- And lastly there is a 2sa1175 (as a muting switch i guess). Same sources suggested bc556. Is it ok? Better equivalent that can be found as easily?
Thanks in advance
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A picture would help - parts marked K81 may as well be 2SK381 from Mitsubishi or 2SK2881 from Isahaya...
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Yep, K81 with round leads should be the Mitsubishi 2SK381, B-rank as pictured in your photo. (Isahaya 2SK2881 have rectangular leads. Confusingly, while their 2SK2881 are the ones marked K81, Isahaya also produce a direct replacement for 2SK381 - the 2SK2880, marked K80. 🙄)
Thanks for the help Petoluk.
That takes a bit of weight off my shoulders, since i ordered k81-2sk381 from china . It would be a pity having ordered the wrong transistor out of code confusion.
If you have any ideas regarding my other questions on equivalents and compatibility please let me know.
That takes a bit of weight off my shoulders, since i ordered k81-2sk381 from china . It would be a pity having ordered the wrong transistor out of code confusion.
If you have any ideas regarding my other questions on equivalents and compatibility please let me know.
First, when asking for help with parts replacement it will be logical to provide
all marking on the case.
It is my understanding that this marking is for the 2SK381 from Mitsubishi - there
were few more times when people were asking about this part replacement, in another
equipment.
https://www.ebay.com/itm/355706753553
Pay attention to the last letter on the case - grade for Idss and Vp.
The other parts for replacement will be:
2SK246
2SK381 - as will be printed in the catalogs
2SK30
with the comparable grade.
And Isahaya part =2SK381, licensed from Mitsubishi, with improved case.
https://www.idc-com.co.jp/product/Search/Discreet/en/161
For the 2SC2785 from NEC - there are plenty to be found in Google, just pay attention to
the grade -the first letter on the second line, and all small details on the case and leads.
2SA1175 is complementary to the C2785, so may be they were used in the circuit for the same
function, then they must have the same grades, since you already have the original parts.
https://ampslab.com/Freewares/2sa1175.pdf
all marking on the case.
It is my understanding that this marking is for the 2SK381 from Mitsubishi - there
were few more times when people were asking about this part replacement, in another
equipment.
https://www.ebay.com/itm/355706753553
Pay attention to the last letter on the case - grade for Idss and Vp.
The other parts for replacement will be:
2SK246
2SK381 - as will be printed in the catalogs
2SK30
with the comparable grade.
And Isahaya part =2SK381, licensed from Mitsubishi, with improved case.
https://www.idc-com.co.jp/product/Search/Discreet/en/161
For the 2SC2785 from NEC - there are plenty to be found in Google, just pay attention to
the grade -the first letter on the second line, and all small details on the case and leads.
2SA1175 is complementary to the C2785, so may be they were used in the circuit for the same
function, then they must have the same grades, since you already have the original parts.
https://ampslab.com/Freewares/2sa1175.pdf
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