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Luxman r-1050 quick question

Chriswashere

Chriswashere

Active Member
Hello, a long time ago I received a luxman r-1050 with a bad channel. I replaced all the blown parts except for the driver transistors which I need help with. I lost track of the 2 good driver transistors so I have no idea what models to order. I'm pretty sure the pair consisted of a 2SD427 and a 2SB557 transistor, but the manual is showing some odd transistor models that I KNOW were not in my unit. Even if I do figure out the correct transistors I probably won't recall which goes where. I guess this is why you don't start a project and then get back to it 2 years later.

Anyways if someone can peek in their 1050 (you can do this without even taking it apart I believe), and tell me what drivers it actually has that would be very very appreciated. I have to admit that i'm not really all that great at this stuff, but this is just another experiment to see what I can actually fix.
 
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You mean the Outputs?
How about these?
MJ15023/MJ15024
Or:
MJ21193/MJ21194

Much better that the originals and probably cheaper.
 
A 2SD427 would be an output transistor, not a driver transistor. If so, use MJ21193 and MJ21194, available from Digikey. These transistors far exceed the specs of the originals and you will never blow them up. The NPN transistor goes in Q109 and the PNP goes in Q110. Don't forget to test Q106.
 
Oh my bad yes they are the outputs. I know the one was a 2sd427 (I have a lot of these actually), but what was the other?

Thank you both, I may look into the equivalents but if I have the originals off hand I might as well use them I suppose.
 
Chriswashere said:
Oh my bad yes they are the outputs. I know the one was a 2sd427 (I have a lot of these actually), but what was the other?

Thank you both, I may look into the equivalents but if I have the originals off hand I might as well use them I suppose.
Click to expand...
2SB557 is the compliment to 2sd427.
 
That's what I thought but it's always to make sure before accidentally blowing something up. Thank you very very much. I really appreciate it.
 
Originals were 2SB541 and a 2SD388.
At least according to the scat I found at HiFi Engine.
Previous repair?
 
How do you have original spares? When did you get them? 2SB557 / 2SD427 is one of the most widely faked transistors around, and has been for as long as it has been obsolete (70's or thereabouts). Fake transistors will give you a very bad time.
 
zebulon1 said:
Originals were 2SB541 and a 2SD388.
At least according to the scat I found at HiFi Engine.
Previous repair?
Click to expand...

My recently acquired R-1050 also has the 2SD427 & 2SB557 and it is original untouched condition except for 1 bulb being changed. There are some transistors on the amp board as well that are different from the HiFi schematic.
 
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