Pioneer SX 850 Phono Stage problem

[markthefixer]

new one on me, the stuff stops...

 

[Thocom]

You've hit the problem square on the nose, it IS the 2sa725 transistors in the phono amp that are failing. A few bucks worth of parts and she'll be singing sweeter than you've ever heard her before!!

BUT THOSE ARE OLD PARTS LISTS!! There have been some changes,here's a somewhat updated post:

edit - and please check this against YOUR phono amp to be sure we have the correct board number and appropriate parts list. There COULD be two rows of three caps in line with pins 3 and 5 on the board, then we are dealing with an older (undocumented) variant of the board. The old board that I have specified parts for has two rows of TWO caps in line with pins 3 and 5 on the board.

Hello, I know this is an old thread, but I am currently ordering all of these parts. The transistors specified for q3,q4, q5, and q6 are now obsolete.
What is the difference between these and thrones specked for q1 and q2? Can I just use all of the same?
I did not have a "crack or pop" when using the phono sections, but I do have very low volume.

Thanks,
Tom

 

[tsd71]

Hello, I know this is an old thread, but I am currently ordering all of these parts. The transistors specified for q3,q4, q5, and q6 are now obsolete.
What is the difference between these and thrones specked for q1 and q2? Can I just use all of the same?
I did not have a "crack or pop" when using the phono sections, but I do have very low volume.

Thanks,
Tom

Use KSC1845FTA for the 2Sc1313's (4 total) Q3,Q4,Q5,Q6
Use KSA992FBU for the 2SA725's (2 total) Q1,Q2
Both from Mouser.com

 

[Watthour]

Q1-2 are PNP, whereas Q3-6 are NPN (opposite polarity). Q3-6 can be substituted with Fairchild KSC1845F.

While on that board, it might make sense to replace C7/8. C11/12, and C17/18 with fresh caps of the same ratings.

 

[Thocom]

Q1-2 are PNP, whereas Q3-6 are NPN (opposite polarity). Q3-6 can be substituted with Fairchild KSC1845F.

While on that board, it might make sense to replace C7/8. C11/12, and C17/18 with fresh caps of the same ratings.

Thanks! Yup, for sure, I am replacing all the caps while I'm in there. These were just the last parts I needed clarification on and my Mouser order is ready to go.

Thanks again,
Tom