Up to date (2017) Pioneer SX-1050 recap list and more

Discussion in 'Pioneer Audio' started by Stevescivic, Aug 23, 2017.

  1. Stevescivic

    Stevescivic Active Member

    Messages:
    198
    Can the kind and super experienced folks on AK please review my list of parts I've ordered for my SX-1050 rebuild project?

    MTF/TSD71 and MattSD have provided me with either older or more recent lists of parts that can be ordered from Mouser and I've gone through the list a few times and MattSD has even skimmed over my list and have pointed out at least 1 mistake in my list. How the list is structured is fairly straight forward. It shows the original Pioneer part # or value of component, the part # suggested by MTF from several years ago, MattSD's suggested replacement part and the last column shows what I actually ordered.

    I would've likely used MattSD's list had I not pulled the "click to order" button before receiving his list. Long story short I had to do a comparison of what Mark and Matt had suggested to see how my ordered lined up to their suggestions. Column F (highlighted in green) are the items that I ordered and MattSD has flagged a transistor in the protection circuit (highlighted in orange) that is an UNSUITABLE replacement.

    I'm specifically concerned with the transistor/diodes and resistor replacements. I normally do not replace transistors and heaven forbid if I install one of them and blow up my receiver as a result of an incorrect part.

    Although I'm certain that 99% of the items I've ordered are in fact good (remember column F is what I purchased). I am asking AK'ers to help point out other parts of concern that should be replaced with something more suitable?


    Many thanks,
     

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  2. r887661

    r887661 AK Subscriber Subscriber

    Messages:
    159
    Location:
    Ludington, Michigan
    This will be a great help, thank you...
     
  3. Stevescivic

    Stevescivic Active Member

    Messages:
    198
    You’re most welcome! I am listening to my 1050 as I type this. I have two 1050 receivers side by side with the second unit about 10% complete in its restoration.

    The list is UP TO DATE as of October 9th, 2017. All components were ordered from Mouser.
     
  4. MOEB74

    MOEB74 AK Subscriber Subscriber

    Messages:
    317
    Thanks for this list... so basically all in all, if I order these parts, that would be a complete list of components to OH one unit thoroughly? How many did you come across that you could not swap over?
     
  5. arnold_a1968

    arnold_a1968 New Member

    Messages:
    46
    i think there is a missing Transistor at AWM-090, Protection Cirsuit Assembly, Q5 2SA733-Q, any suggested replacement for it?
     
  6. redk9258

    redk9258 Super Member

    Messages:
    1,450
    Location:
    Illinois, close to St. Louis.
    Maybe KSA733C. Check data sheets. Note "C" suffix for center collector.
     

     

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  7. arnold_a1968

    arnold_a1968 New Member

    Messages:
    46
    Thanks, i'm done rebuilding my SX1050 but had one issue, Pop sound when power up, i found out when i connect separate the Pre Out and connect it to another 8500 main, Pop sound comes out every time when power on.
    I have recap and replace the drivers of the Contorl board and EQ board but still got this pop sound so i leaning that somewhere in the protection board or power supply board is causing the Pop sound. But i will try to work first with the Protection circuit board to replace the drivers and the relay.

    Do you have replacement part number for the Relay S1 ASR-020??
     
  8. deltalight

    deltalight AK Subscriber Subscriber

    Messages:
    251
    Location:
    Minneapolis
    Q17: 2SB536A: 2SA1859A
    Q18: 2SB536A: 2SA1859A
    Q19: 2SD381A: 2SC4883A
    Q20: 2SD381A: 2SC4883A
    S1: ASR-020 4PDT 5A 48VDC: MY4-02-DC48: 653-MY4-02-DC48
    S2: ASR-015 DPDT 10A 48VDC: LY2-DC48: 653-LY2-DC48
     
  9. arnold_a1968

    arnold_a1968 New Member

    Messages:
    46
    many thanks DeltaLight
     
  10. arnold_a1968

    arnold_a1968 New Member

    Messages:
    46
    another missing replacement for the Flat Amplifier AWG-040, Q5 & Q6 > 2SK30AW-Y, any suggestion?
     
  11. HVHiFI

    HVHiFI Hudson Valley HiFI Subscriber

    Messages:
    1,950
    Location:
    Chester, NY
    That is a FET, leave it alone unless there is an issue.
     

     

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  12. arnold_a1968

    arnold_a1968 New Member

    Messages:
    46
    i have an issue, pop sound when amp is turned on, i may replace all the FETs from power supply to each board as it is quite hard to trace where the pop coming from but for sure, when i disconnect the pre and main jumper there is no pop, so the power amp is eliminated thus only left are the power supply to pre amp and the pre amp itself.

    no idea?
     
  13. HVHiFI

    HVHiFI Hudson Valley HiFI Subscriber

    Messages:
    1,950
    Location:
    Chester, NY
    2N5457 is close. Replacing for no reason is never good though. The subs are never exactly the specs of the original.
     
  14. kramden

    kramden Active Member

    Messages:
    159
    Did you have this pop sound before all the new parts went in?
     
  15. arnold_a1968

    arnold_a1968 New Member

    Messages:
    46
    sorry for late reply, when i got my sx1050, it went at once to my tech for restoration as the seller told me something about the left channel or right channel to be weak.
    so i told my tech to replace all the caps including the main power cap. then after i got back the unit i heard pop sound when it is first turned on and pop sound comes back
    when it is turned on when not in used for at least 30 mins.

    I replaced the drivers and relay at the protection board and just cleaned the main relay but still i heard pop sound. I disconnect the Pre and Main but still there is pop sound.
    So I'm leaning either the main power supply board driver is faulty, may not be the power amp since i only got pop sound when it is turned on for the first time.

    Any idea?

    Anybody has suggestion for replacement the Bridge Rectifier KBH25-04??
     
  16. HVHiFI

    HVHiFI Hudson Valley HiFI Subscriber

    Messages:
    1,950
    Location:
    Chester, NY
    Earlier you said when you pull the pre-main jumpers the sound went away, which is it since that'll tell you where to focus in. Is the pop from both channels or just one? Did your tech replace the two main power rail filter caps? Have you replaced the known to be problem 2sa726 and 2sc1312 transistors throughout this unit including the input pairs of the amps?
     

     

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  17. arnold_a1968

    arnold_a1968 New Member

    Messages:
    46
    at first when i pulled the pre-main jumpers pop went away but after few hours then it came back. pop is on both channel. 2 main power caps replace with Nichicon 22000uF (not cheap though).
    Drivers where replace on EQ board, Control Amp board and Protection Circuit board. I didn't replace the Flat Amp board where the 2SA725/2SA726 is located so will try that to replace with KSA992 but
    do you think that will help since without the jumper, pop comes out. Which Transistor input of the Power Amp, 2SA750?
     
  18. HVHiFI

    HVHiFI Hudson Valley HiFI Subscriber

    Messages:
    1,950
    Location:
    Chester, NY
    Since the pop happens without the jumpers symetrically, I would lean on the power supply / protection circuit being the issue feeding the amp. The protection circuit on these is very rich with gremlins; we usually overhaul that board with new caps, transistors, and diodes. The drive transistors for the relay can cause noise as well, When the relay closes if the transistors are leaky it will arc as it closes. Since your issue does not occur after the unit warms up I'd be leaning towards a semiconductor problem.
     
  19. arnold_a1968

    arnold_a1968 New Member

    Messages:
    46
    Update: replaced the input transistor of the amp Q1 to Q6 2SA750 with 2SA992, pop sound still there but quite faint sound but still can be heard.
    The protection Circuit board already re-capped and replaced all the drivers and new Relay only remaining are the diodes >> Option1
    The last option is to replace all drivers of the Main Power Supply, this was also re-capped >> Option2

    Main Power Supply board is quite difficult to manage on removing the transistor, have to remove all the wiring so i can pull out the board for easy replacement.
     
  20. Blue Shadow

    Blue Shadow I gotta get me a new title

    Messages:
    20,163
    Location:
    SE PA
    SX-5580 relay

    SX1050 relay

    Both mentioned in this thread an EWs big Pioneer Relay thread.
     
    Last edited: Feb 15, 2018

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