Pioneer Spec 1 Pre-Amp Sound Issue

Discussion in 'Pioneer Audio' started by xXColdShotXx, May 13, 2018.

  1. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    Could you tell me where to find a cap and transistor BOM list for the spec 2? Thanks. I've searched the AK forums and found nothing, unless I worded it wrong.
     

     

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  2. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
  3. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    I need replacements for 647-LGY2A102MELA30, 647-UPW1A471MPD, 512-KSC2690AYS,
    667-EEU-FM1A471, 505-MKS2C041001FJC00 they are backordered on mouser.
     
  4. mattsd

    mattsd AK Subscriber Subscriber

    Messages:
    1,598
    Location:
    Cincinnati, Ohio
    Parts needing subbed in bold:

    647-LGY2A102MELA30
    : 661-EKMH101VNN122MQ
    647-UPW1A471MPD: 647-UPW1C471MPD
    667-EEU-FM1A471: 667-EEU-FM1A471B
    505-MKS2C041001FJC00: 505-MKS2C041001FJI00

    On the 2690, there is no good sub for that, though a KSC2383 can do temporarily if you have to replace the 2SC1166. The 2690s are due in on May 30th, so it's not too long of a wait.. Also, I made some changes from the list posted currently to the transistors used for the SEPP drivers in the phono, filter, tone and buffer amp sections. These have better dissipation than the KSC2383/KSA1013 combo and the best performance out of the 4 different transistor pairings I tried out for subbing the 1885/912 pairs.

    Input Circuit Board (AWF-017)

    Q7: 2SC1885: 757-TTC004BQ
    Q8: 2SC1885: 757-TTC004BQ
    Q9: 2SA912: 757-TTA004BQ
    Q10: 2SA912: 757-TTA004BQ

    Filter Amp Board (AWM-082)

    Q1: 2SC1885: 757-TTC004BQ
    Q2: 2SC1885: 757-TTC004BQ
    Q3: 2SA912: 757-TTA004BQ
    Q4: 2SA912: 757-TTA004BQ
    Q5: 2SC1885: 757-TTC004BQ
    Q6: 2SC1885: 757-TTC004BQ
    Q7: 2SC1885: 757-TTC004BQ
    Q8: 2SC1885: 757-TTC004BQ
    Q9: 2SC1885: 757-TTC004BQ
    Q10: 2SC1885: 757-TTC004BQ
    Q11: 2SA912: 757-TTA004BQ
    Q12: 2SA912: 757-TTA004BQ

    Tone Amp Board (AWG-035)

    Q7: 2SC1885: 757-TTC004BQ
    Q8: 2SC1885: 757-TTC004BQ
    Q9: 2SA912: 757-TTA004BQ
    Q10: 2SA912: 757-TTA004BQ
    Q11: 2SC1885: 757-TTC004BQ
    Q12: 2SC1885: 757-TTC004BQ
     
  5. markthefixer

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

    Messages:
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    Location:
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    Matt, for the c1885/a912 sepp drivers, did you try the:
    512-KSA1220AYS to-126 ecb 120/a160 1.2a 1.2w/20w 175mhz 35-320hfe
    512-KSC2690AYS to-126 ecb 120/a160 1.2a 1.2w/20w 175mhz 35-320hfe
    assuming that eventually the ksc-2690's will be available.

    NOT to change your mind, but to change MINE with empirical evidence.

    757-TTA004BQ pnp to-126 ecb 160v 1.5a 1.5w/10w 100mhz 80-280hfe
    757-TTC004BQ npn to-126 ecb 160v 1.5a 1.5w/10w 100mhz 80-280hfe

    The specs are similar, slightly slower.
     
  6. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    Thank you all very much for the updated parts list.
     

     

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  7. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    Here's the Spec 1 and 2 I'm ordering parts for. I hope to get it lined out. Once I get it working good I'll clean it up and polish it.
     

    Attached Files:

  8. mattsd

    mattsd AK Subscriber Subscriber

    Messages:
    1,598
    Location:
    Cincinnati, Ohio
    I did, I tried the KSC2690/KSA1220, KSC3503/KSA1381, KSC2383/KSA1013 and the TTC/TTA004 combos. I will be doing a detailed write up, but my bench is slammed so time is limited right now.
     
  9. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    Hey Mattsd, do you know of a spec 1 power switch lamp replacement?
     
  10. mattsd

    mattsd AK Subscriber Subscriber

    Messages:
    1,598
    Location:
    Cincinnati, Ohio
    8v 50ma 4.7mm lamp, AK member @dgwojo has them. You can also use a 5mm LED if you choose.
     
  11. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    I have some led bulbs that work in the Yamaha MX-800/U VU meters, not sure what voltage/mA they are. I got them from ebay a while back.
     

     

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  12. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    Hey Mattsd, could you tell me the output transistor mica insulator part # for the spec 2? The spec 2 takes 6 each in total and 3 of each mj21195g and mj21196g for each heatsink, right? Thanks.
     
    Last edited: May 18, 2018
  13. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    I am curious, are the spec 1 and sx-1250 volume's similar internally with laser precision cut parts and are both gold or whatever? I need to clean the spec 1 volume better. I unsoldered my sx-1250 volume and loosened the screws enough to get D5 in there, but not sure I could do the same with the spec 1.
     
  14. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    What is a good cheap Fluke for repairing electronics? Fluke 12E+, 15B+ or 17B+?
     
    Last edited: May 19, 2018
  15. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    What kind of screws and other hardware will I need to put new filter caps in the Spec 2?
     
  16. zebulon1

    zebulon1 Getting behind on work. I need help? Subscriber

    Messages:
    4,740
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    Las Vegas Nevada
    I've been using these:
    Mouser Thermal Interface
     

     

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  17. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    The day the spec 2 popped and went into protection mode I felt of the speaker wire of the right channel and it was kinda warm, what would that suggest?
     
  18. xXColdShotXx

    xXColdShotXx Active Member

    Messages:
    219
    Location:
    Lexington, Kentucky
    Got all the caps and transistors changed in the spec 1, but when I try to test with DBT the light won't come on at all and it's getting juice to the spec 1 main electric cord and the power switch read the same thing. When off it has more juice than when I turn it on. I am using a 75W bulb.
     
  19. avionic

    avionic " Black Knights " Subscriber

    Messages:
    41,563
    Location:
    Fort Dodge, Iowa
    Check your power switch and mains fuse..
     
  20. avionic

    avionic " Black Knights " Subscriber

    Messages:
    41,563
    Location:
    Fort Dodge, Iowa
    Broken wires or cracked solder connections..
     

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