I’m having trouble with a Sony STR-6055 MPX board in the tuner which I’ve read is very common with this model. My voltages are pretty far off. I barely touched Q401 and a leg snapped, super thin. It’s a 2SK23, no other info on it, no Idss ranking. I read that 2SK117 is a good fit, but then not because of high ciss/crss.
I saw someone say they replaced this exact Q401 with a 2N4393 with a vgsoff of 1.17v and it’s of 8.45 mA and that it worked well enough. I don’t know what they used to get their measurements.
The device that is in here has a small little nubbin of metal still sticking out of the case that used to be the leg, so I can still measure it with a Peak DCA75. It measures with a vgsoff of 1.71v and a idss of 4.92 mA. Seems a decent way off of what he used. Though this one may be defective and not measuring as it did when new.
Here it is in circuit. It has about 15v on it.
I’m curious if what I have would make a good replacement.
2SK170bl. I only have BL unfortunately, on this same tester they are measuring with an Idss of 6.5ish and up. So would be in line perfectly with what that other person used (2N4393). I have hundreds so would be cool to use.
2SK30A. Idss seems a bit lower in the 3-ish range. I have about 25 or so
2N5457. These have an Idss on the low side, about 2-1/2. Again not very many, maybe 20
2N5458. These seem to be fairly dead on, Idss of around 4-1/2 to 6. Only have 20 so if something else works better that would be nice. Not sure if this is a good fit anyways. Luckily it’s still available so I can buy more.
I also have several smd options I can put on adapter board. For example 2SK209 in Y, GR, and BL.
What are thoughts? Go with what the other person used and use one of the 2SK170s or should I use the 2N5458, or something else? Not sure how close it needs to be.
Thank you,
Dan
I saw someone say they replaced this exact Q401 with a 2N4393 with a vgsoff of 1.17v and it’s of 8.45 mA and that it worked well enough. I don’t know what they used to get their measurements.
The device that is in here has a small little nubbin of metal still sticking out of the case that used to be the leg, so I can still measure it with a Peak DCA75. It measures with a vgsoff of 1.71v and a idss of 4.92 mA. Seems a decent way off of what he used. Though this one may be defective and not measuring as it did when new.
Here it is in circuit. It has about 15v on it.
I’m curious if what I have would make a good replacement.
2SK170bl. I only have BL unfortunately, on this same tester they are measuring with an Idss of 6.5ish and up. So would be in line perfectly with what that other person used (2N4393). I have hundreds so would be cool to use.
2SK30A. Idss seems a bit lower in the 3-ish range. I have about 25 or so
2N5457. These have an Idss on the low side, about 2-1/2. Again not very many, maybe 20
2N5458. These seem to be fairly dead on, Idss of around 4-1/2 to 6. Only have 20 so if something else works better that would be nice. Not sure if this is a good fit anyways. Luckily it’s still available so I can buy more.
I also have several smd options I can put on adapter board. For example 2SK209 in Y, GR, and BL.
What are thoughts? Go with what the other person used and use one of the 2SK170s or should I use the 2N5458, or something else? Not sure how close it needs to be.
Thank you,
Dan
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I would recommend the 2N5458, good HF specs.
The 2SK23 (not specified the 'A' grade?) runs on gate bias, a bit tricky...
The 2SK23 (not specified the 'A' grade?) runs on gate bias, a bit tricky...
Oh fantastic info to know. Unfortunately the 2N5459 isn’t readily available anymore. I have the 2N5458, would you agree that’s also a good sub?
Dan
First, some data for the 2SK23 and the "A" variation, that I was able to find on the NET:
2SK23 Sony Specifications @Vds=10V:
Vbr GSS 18V-
Max. PD (W) 150m
Ciss Max. (F) 5.0p
gfs Min 2.7m
Idss Max. (A) 16m
Igss Max. (A) 10n
Vp Max. 4.9V
Oper. Temp (°C) Max. 150
Second, similar problem was discussed here already, which will be helpful for you:
https://www.diyaudio.com/community/threads/sony-str-6055-repair-mpx-issue.375495/
Hope it will help.
The voltages on the sch are confusing... Another example to compare:
And yes, there was "recommendation" to replace it with 2N5459, but you can try
2N5458, selected for the highest Idss. Nothing will burn or explode, you will hear the result.
2SK23 Sony Specifications @Vds=10V:
Vbr GSS 18V-
Max. PD (W) 150m
Ciss Max. (F) 5.0p
gfs Min 2.7m
Idss Max. (A) 16m
Igss Max. (A) 10n
Vp Max. 4.9V
Oper. Temp (°C) Max. 150
Second, similar problem was discussed here already, which will be helpful for you:
https://www.diyaudio.com/community/threads/sony-str-6055-repair-mpx-issue.375495/
Hope it will help.
The voltages on the sch are confusing... Another example to compare:
And yes, there was "recommendation" to replace it with 2N5459, but you can try
2N5458, selected for the highest Idss. Nothing will burn or explode, you will hear the result.
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Hello everyone!
I think I can help someone. I found an exact replacement for dual 2SK58, single 2SK23A and single 2SK107.
These are all interchangeable transistors, 2SK58 is dual 2SK23A or 2SK107. These transistors have not been produced for a long time and are hard to find on sale. So, transistor J304 is an alternative replacement for 2SK107, which is indicated in the datasheet. J304 is available on Mouser.
I think I can help someone. I found an exact replacement for dual 2SK58, single 2SK23A and single 2SK107.
These are all interchangeable transistors, 2SK58 is dual 2SK23A or 2SK107. These transistors have not been produced for a long time and are hard to find on sale. So, transistor J304 is an alternative replacement for 2SK107, which is indicated in the datasheet. J304 is available on Mouser.