Recapping SX-950

Discussion in 'Pioneer Audio' started by gmahoog, Apr 16, 2011.

  1. gmahoog

    gmahoog New Member

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    Hi everybody.

    I've read through a ton of posts and I'm amazed at all the knowledge here. There is some real interesting reading and I've already learned a lot from you guys in the week I've been lurking here.

    I recently fixed a power supply problem and now am thinking of recapping the whole unit. I've searched all over in the Pioneer and Vintage forums, but can't find a cap list for the SX-950. I've seen SX-850, SX-1050 and many others, but the SX-950 just hasn't turned up.

    I am hoping that someone could provide me a link to a cap list.

    I also noticed that most everyone goes with Nichicon capacitors. Are these superior to other brands or just the best fit?

    Any help would be greatly appreciated.
     
  2. montecarlossfan

    montecarlossfan Active Member

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    nichicon's are a good value for the money...and we use the pw series for power supply circuits..and kl for the audio path typically..FWIW I would verify whats in your unit with a service manual and the unit in front of you..then make your own list...best way IMO
     
  3. Sir.Byrd

    Sir.Byrd Lunatic Member

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    It is best to make your own cap list for each unit, why don't you take it apart and catalog the parts you are going to replace. Make note of unlabeled tantalum capacitors to look up in the schematics later, and familiarize yourself with the layout of the unit.
    I use PM for the power supply (typically) and Nichicon caps in this order based on availability and size (The KZ are big!) KZ, FG, KT, KW, FW.
    Panasonic ECQ polyester film caps for caps under 2.2uF
    Nichicon is widely available from mouser, but if you want to use Panasonic caps (like FC, FM series) you must order from somewhere like Digikey.
    Furthermore, I've found the best sounding caps are Elna Silmic II, and the best place to get those is AK sponsor partsconnexion.com
     
  4. mattsd

    mattsd AK Subscriber Subscriber

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    Pioneer SX-950 Recap List

    Here is my 950 recap list, hope it helps! It details each cap and its replacement. Also included are the transistors that are known to get noisy in this model and their replacements.

    Pioneer SX-950 recap list (Updated 7/31/14)

    Equalizer Amp Assembly (AWF-011)

    AWF-011: C1: 1uF 25v CSSA: 647-UKL1H010KDDANA 1uF 50v
    AWF-011: C2: 1uF 25v CSSA: 647-UKL1H010KDDANA 1uF 50v
    AWF-011: C7: 330uF 6.8v CEA: 667-EEU-FM1C331 330uF 16v
    AWF-011: C8: 330uF 6.8v CEA: 667-EEU-FM1C331 330uF 16v
    AWF-011: C11: 3.3uF 25v CEANL: 647-UKL1H3R3KDDANA 3.3uF 50v
    AWF-011: C12: 3.3uF 25v CEANL: 647-UKL1H3R3KDDANA 3.3uF 50v
    AWF-011: C17 100uF 35v CEA: 667-EEU-FM1H101 100uF 50v
    AWF-011: C18 220uF 25v CEA: 667-EEU-FM1V221 220uF 35v

    AWF-011: Q1: 2SA725: 512-KSA992FBU
    AWF-011: Q2: 2SA725: 512-KSA992FBU
    AWF-011: Q3: 2SC1313: 512-KSC1845FTA
    AWF-011: Q4: 2SC1313: 512-KSC1845FTA
    AWF-011: Q5: 2SC1313: 512-KSC1845FTA
    AWF-011: Q6: 2SC1313: 512-KSC1845FTA

    If the B version:

    AWF-011: C??: 100uF 6.3v CEA: 667-EEU-FM1A101 100uF 10v
    AWF-011: C??: 100uF 6.3v CEA: 667-EEU-FM1A101 100uF 10v

    Switch Assembly Board (AWS-094)

    AWS-094: C1: 220uF 6.8v CEA: 667-EEU-FM1V221 220uF 35v

    Flat Amp Board (AWG-038)

    AWG-038: C1: 2.2uF 50v CEANL(NL): 647-UKL1H2R2KDDANA 2.2uF 50v
    AWG-038: C2: 2.2uF 50v CEANL(NL): 647-UKL1H2R2KDDANA 2.2uF 50v
    AWG-038: C5: 4.7uF 50v CEANL(NL): 647-UKL1J4R7MDD 4.7uF 63v
    AWG-038: C6: 4.7uF 50v CEANL(NL): 647-UKL1J4R7MDD 4.7uF 63v
    AWG-038: C13: 220uF 35v CEA: 667-EEU-FM1V221 220uF 35v
    AWG-038: C14: 220uF 35v CEA: 667-EEU-FM1V221 220uF 35v
    AWG-038: C17: 10uF 25v CSZA: 647-UKL1E100KDDANA 10uF 25v
    AWG-038: C18: 10uF 25v CSZA: 647-UKL1E100KDDANA 10uF 25v
    AWG-038: C23: 4.7uF 50v CEANL(NL): 647-UKL1J4R7MDD 4.7uF 63v
    AWG-038: C24: 4.7uF 50v CEANL(NL): 647-UKL1J4R7MDD 4.7uF 63v
    AWG-038: C25: 100uF 10v CEANL(NL): 647-UKL1A101KEDANA 100uF 10v
    AWG-038: C26: 100uF 10v CEANL(NL): 647-UKL1A101KEDANA 100uF 10v
    AWG-038: C27: 100uF 50v CEA: 667-EEU-FM1H101 100uF 50v

    AWG-038: Q1: 2SC1885: 512-KSC2383YTA
    AWG-038: Q2: 2SC1885: 512-KSC2383YTA
    AWG-038: Q5: 2SA725: 512-KSA992FBU
    AWG-038: Q6: 2SA725: 512-KSA992FBU

    Tone Amp Board (AWG-039)

    AWG-039: C13: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
    AWG-039: C14: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
    AWG-039: C15: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
    AWG-039: C16: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
    AWG-039: C19: 100uF 10v CEANL(NL): 647-UKL1A101KEDANA 100uF 10v
    AWG-039: C20: 100uF 10v CEANL(NL): 647-UKL1A101KEDANA 100uF 10v
    AWG-039: C21: 47uF 35v CEA: 667-EEU-FC1V470 47uF 35v
    AWG-039: C22: 47uF 35v CEA: 667-EEU-FC1V470 47uF 35v
    AWG-039: C23: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
    AWG-039: C24: 2.2uF 25v CSZA: 647-UKL1H2R2KDDANA 2.2uF 50v
    AWG-039: C25: .22uF 35v CSZA: 667-ECQ-V1H224JL2 .22uF 50v
    AWG-039: C26: .22uF 35v CSZA: 667-ECQ-V1H224JL2 .22uF 50v
    AWG-039: C29: 10uF 25v CSZA: 647-UKL1E100KDDANA 10uF 25v
    AWG-039: C30: 10uF 25v CSZA: 647-UKL1E100KDDANA 10uF 25v

    AWG-039: Q1: 2SC1312: 512-KSC1845FTA
    AWG-039: Q2: 2SC1312: 512-KSC1845FTA

    Power Amp Board (AWH-059) (Q1 and Q3 & Q2 and Q4 should be gain matched)

    AWH-059: C1: 2.2uF 25v CSSA: 647-UKL1H2R2KDDANA 2.2uF 50v
    AWH-059: C2: 2.2uF 25v CSSA: 647-UKL1H2R2KDDANA 2.2uF 50v
    AWH-059: C3: 1uF 25v CSSA: 647-UKL1H010KDDANA 1uF 50v
    AWH-059: C4: 1uF 25v CSSA: 647-UKL1H010KDDANA 1uF 50v
    AWH-059: C5: 33uF 16v CEA: 667-EEU-FM1V330 33uF 35v
    AWH-059: C6: 33uF 16v CEA: 667-EEU-FM1V330 33uF 35v
    AWH-059: C11: 330uF 10v CEA: 667-EEU-FM1C331 330uF 16v
    AWH-059: C12: 330uF 10v CEA: 667-EEU-FM1C331 330uF 16v

    AWH-059: Q1: 2SA726: 512-KSA992FBU
    AWH-059: Q2: 2SA726: 512-KSA992FBU
    AWH-059: Q3: 2SA726: 512-KSA992FBU
    AWH-059: Q4: 2SA726: 512-KSA992FBU

    VR1: 1K ohm multi offset: 652-3296P-1-102LF 1K ohm 25 turn
    VR2: 1K ohm multi offset: 652-3296P-1-102LF 1K ohm 25 turn
    VR3: 100 ohm single bias: 652-3386H-1-101LF 100 ohm single turn
    VR4: 100 ohm single bias: 652-3386H-1-101LF 100 ohm single turn

    Protection Circuit Assembly (AWM-062)

    AWM-062: C1: .22uF 10v CSSA: 667-ECQ-V1H224JL2 .22uF 50v
    AWM-062: C2: .22uF 10v CSSA: 667-ECQ-V1H224JL2 .22uF 50v
    AWM-062: C3: 330uF 6.8v CEA: 647-UPW1A331MPD 330uF 10v
    AWM-062: C4: 330uF 6.8v CEA: 647-UPW1A331MPD 330uF 10v
    AWM-062: C5: 4.7uF 25v CEA: 647-UPW1V4R7MDD 4.7uF 35v
    AWM-062: C6: 100uF 16v CEA: 647-UPW1V101MPD 100uF 35v

    AWR-062: Q1: 2SC869: 512-KSC1845FTA
    AWR-062: Q2: 2SC869: 512-KSC1845FTA
    AWR-062: Q6: 2SC945: 512-KSC2383YTA
    AWR-062: Q7: 2SC1318: 512-KSC2690AYS
    1N4004 flyback diode is added between pins 9 (anode) and 10 (cathode)

    Power Supply Board (AWR-101)

    AWR-101: C10: 470uF 80v ACH-038 (Snap-in): 667-ECO-S1KP681BA 680uF 80v
    AWR-101: C11: 470uF 80v ACH-038 (Snap-in): 667-ECO-S1KP681BA 680uF 80v
    AWR-101: C12: 2200uF 35v ACH-039 (Snap-in): 667-ECO-S1HA222BA 2200uF 35v
    AWR-101: C13: 1000uF 25v CEA: 647-UPW1V102MHD 1000uF 35v
    AWR-101: C14: 220uF 10v CEA: 647-UPW1C221MPD 220uF 16v
    AWR-101: C15: 470uF 63v CEA: 647-UPW2A471MHD 470uF 100v
    AWR-101: C16: 47uF 16v CEA: 647-UPW1E470MDD 47uF 25v
    AWR-101: C18: 47uF 50v CEA: 647-UPW1J470MPD 47uF 63v
    AWR-101: C19: 47uF 35v CEA: 647-UPW1H470MED 47uF 50v
    AWR-101: C20: 100uF 63v CEA: 647-UPW2A101MHD 100uF 100v
    AWR-101: C21: 47uF 16v CEA: 647-UPW1E470MDD 47uF 25v
    AWR-101: C23: 100uF 35v CEA: 647-UPW1H101MPD 100uF 50v

    AWR-101: Q1: 2SD313: 863-MJE15032G
    AWR-101: Q2: 2SB507: 863-MJE15033G
    AWR-101: Q3: 2SC1318: 512-KSC2383YTA
    AWR-101: Q4: 2SA720: 512-KSA1013YBU
    AWR-101: Q5: 2SC1318: 512-KSC2690AYS
    AWR-101: Q6: 2SA720: 512-KSA1013YBU
    AWR-101: Q7: 2SC1318: 512-KSC2383YTA
    AWR-101: Q8: 2SD313: 863-MJE15032G
    AWR-101: Q9: 2SD313: 863-MJE15032G
    AWR-101: Q10: 2SC869: 512-KSC2383YTA

    BOM List:

    647-UKL1H2R2KDDANA | 10
    647-UKL1H010KDDANA | 4
    647-UKL1H3R3KDDANA | 2
    647-UKL1J4R7MDD | 4
    647-UKL1A101KEDANA | 4
    647-UKL1E100KDDANA | 4
    667-EEU-FM1C331 | 4
    667-EEU-FM1H101 | 2
    667-EEU-FM1A101 | 2
    667-EEU-FM1V221 | 4
    667-EEU-FM1V330 | 2
    667-EEU-FC1V470 | 2
    667-ECQ-V1H224JL2 | 4
    667-ECO-S1KP681BA | 2
    667-ECO-S1HA222BA | 1
    647-UPW1A331MPD | 2
    647-UPW1V4R7MDD | 1
    647-UPW1H101MPD | 1
    647-UPW1V101MPD | 1
    647-UPW2A101MHD | 1
    647-UPW1V102MHD | 1
    647-UPW1C221MPD | 1
    647-UPW2A471MHD | 1
    647-UPW1E470MDD | 2
    647-UPW1J470MPD | 1
    647-UPW1H470MED | 1
    863-MJE15032G | 3
    863-MJE15033G | 1
    512-KSA992FBU | 8
    512-KSC1845FTA | 8
    512-KSC2383YTA | 6
    512-KSA1013YBU | 2
    512-KSC2690AYS | 2
    652-3386H-1-101LF | 2
    652-3296P-1-102LF | 2
     
    Last edited: Jul 31, 2014
  5. gmahoog

    gmahoog New Member

    Messages:
    45
    Location:
    The Hawkeye State
    Thanks for the responses. I understand that making my own list would help me understand the unit better. I have an electronics background so I know I can figure out how it works. I think what I'll do is use Matt's list and study the schematic and board layouts in order to get it all together correctly.

    Like I said before, I really like this site and all the knowledge that is present here. You guys might turn me into a full fledged audio head. I doubt I'll end up owning all the gear that many of you have though. :music:
     
  6. Detailman

    Detailman Addicted to tweaking

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    Never say Never:banana::banana::banana:


    Suggestion is to do the important boards first.
    Flat amp board
    Power supply board
    Amplifier board
    Phono board if so inclined.

    This sometimes makes the project more enjoyable as you can test your work at stages.
     
  7. gmahoog

    gmahoog New Member

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    Location:
    The Hawkeye State
    I guess I have a pretty good start. I have an SX-780 that I bought new. It started making a popping sound about 20 years ago so it's been on the shelf. I picked up the SX-950 a year ago. It started having some noise issues in the left channel so I started using this Techniques amp I bought about 10 years ago. It sounded like crap so I decided to give the SX-780 a try. Cleaned it up a bit and haven't had a problem for over a week. I'm planning to refurbish it too after I'm done with the SX-950.
     
  8. gmahoog

    gmahoog New Member

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    The Hawkeye State
    To be fair to the Technics amp, it was a cheap one I bought new for around $120.00. It served it's purpose at the time so it's not a piece of crap. It just doesn't have the warmth of the vintage Pioneers.

    I guess I could have spelled it correctly while cutting it down in my other post.
     
  9. day67

    day67 Super Member

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    RI, the Ocean State
    Thanks, Mattsd for the list. I'm assuming its's an updated one with gettable part #'s. I'll be doing a rebuild of my tone amp and flat amp board soon so this thread is very timely! Gmahoog, let us know how you're progressing. I've been watching the 850 threads/posts (of which there are many more of than the 950) but I understand most of the caps numbers etc are the same. Good advice above, I'll see what each board has in ACTUAL parts and go from there.
     
  10. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Probably best to make sure all the voltages getting to the individual boards is correct, so doing the power supply 1st is paramount. Then the protection board. Doing these two first will ensure that any problems encountered later on shouldn't be power supply related.

    After the power supply and protection boards are stable, Go thru the boards in order from phono section to the Main amp. You can note incremental increases in sound quality, all the way to the output's.

    Larry
     
  11. gmahoog

    gmahoog New Member

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    Location:
    The Hawkeye State
    I was reading the following SX-850 thread and on page 3 Markthefixer stated that C13 and C14 on the Tone Amplifier should be 2.2uF instead of 10uF.

    http://www.audiokarma.org/forums/showthread.php?t=356196

    I checked the SM I have and it shows 10uF in the parts list and the board layout. I'll be sure to check the actual caps I'm replacing as I do this.

    Great advice to check the circuit boards for the caps being replaced.
     
  12. gmahoog

    gmahoog New Member

    Messages:
    45
    Location:
    The Hawkeye State
    Thanks Larry. I'll probably start with the power amp because I already have it pulled out for work. I had a noisy left channel I isolated to come from the amp board, but then noticed the -51V was -62V. (Good call on doing power supply first.) I found that Q7 on the power supply was shorted and the left channel problem cleared up after I got the voltage fixed. I figure I might as well replace the caps on the power amp while it's still apart. Do you think I should replace the power amp "board" transistors too? (The outputs checked OK.)

    Regards,
    Dave H.
     
    Last edited: Apr 18, 2011
  13. mattsd

    mattsd AK Subscriber Subscriber

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    And I quote from my post:
    gmahoog, what did you replace Q7 with? Also, I included the transistors on the power amp, flat amp and EQ amp in my list that should be replaced. The power supply is coming up.
     
    Last edited: Apr 18, 2011
  14. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    I've found over the years that production line changes usually DON'T make it to the schematics. Oft times when that happens it's an improvement by the designers and as incremental changes they don't make the paper. If there are a bunch done at one time, chances are they WOULD make the paper. But it's not certain. Use the manual as a general guide, not as the ultimate reference.

    The best way to this is to make a list from the parts list then compare each and everyone on the unit itself. Make changes on the list to reflect the parts on the unit itself. This will ensure the latest revision at the point in time that your particular unit was made.

    Larry
     
  15. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    Pioneer ran their units "hot" or right at the upper limit of the SOA. Most of the Receivers I've seen from PIONEER have the Power supply on the bottom, facing down and the heat made is trapped. I'd replace all the transistors with modern equivalents that dissipate more heat, and are not affected as much by the heat generated. Also if you have the room upgrading or adding to the heatsinks will help.

    I believe Matt has a list of upgraded transistors for the power supply. At minimum replace ANY 2SA720, 2sa725,2sa726's. I can't remember what the replacement is, Search for them in the threads. They are very problematic. Breakdown, cause noise, etc.

    Larry
     
    Last edited: Apr 18, 2011
  16. gmahoog

    gmahoog New Member

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    Matt,

    I used 512-KSA940TU for Q7.

    Dave H.
     
  17. mattsd

    mattsd AK Subscriber Subscriber

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    That's a little bit overkill, a KSC2383YBU would work just as well, but the 940 is okay. The other transistor that should be replaced is Q5, replace it with a 512-KSC2690AYS.
     
  18. markthefixer

    markthefixer On Hiatus, dealing with Dad's estate full time Subscriber

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    HEY!!!!

    DON'Y MIX A'S (pnp) and C's(npn) !!!!!!!!!!!!!!!!!!!!!


    EXACTLY WHAT board's Q7 and Q5???????????????​
     
  19. mattsd

    mattsd AK Subscriber Subscriber

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    Whoa! That's what I get for not looking at the manual and the post closely. He's talking about Q7 on the power supply board AWR-101, here, this is from post #12:

    It is possible he meant KSC2073TU, but miss typed or copied the wrong number, as he said the problem cleared up, which it would not have if he had put a PNP in there.
     
    Last edited: Apr 19, 2011
  20. gmahoog

    gmahoog New Member

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    Location:
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    Oops. I used a KSA940TU for Q2 on the power supply board.

    Mark, you're on top of everything. :thmbsp:
     
    Last edited: Apr 19, 2011

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