Pioneer SG-9800 equalizer, LED replacement and recap

Discussion in 'Pioneer Audio' started by leesonic, May 21, 2013.

  1. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    I did some work on my Pioneer SG-9800 equalizer today. I soldered in three new pots that I got from eBay. I also replaced the tape monitor switches and the attenuator switches with some that came from an old Sharp tape deck (motto : never throw anything away). I had to trim down the PCB pins with a Dremel, but they fitted just right after this.

    I also took the chance to replace the LEDs, the three round ones behind the power, tape and overload lights, plus the 24 that light up the sliders. For these, I used Mouser part number 604-WP113SRDT, these are listed as 2mm x 5mm x 7mm. I've heard that 2mm x 4mm LEDs will fit exactly, but these ones have a light output of 80mcd. I simply shaved the long edges down with a Dremel, and then finalizing them by rubbing the edge on some sandpaper.

    The three pictures below show the new LEDs on the right bank, with the old ones on the left bank. Quite a difference don't you think? Of course, the camera makes them look WAY brighter than they really are, at times the shutter speed was dropping down to 1/2 second. Plus, these were all taken with the slider knobs removed, except on one for comparison. The pictures were taken in a darkened garage, with the only light coming in from a window to the left.

    PioneerSG-9800-01.jpg
    PioneerSG-9800-02.jpg
    PioneerSG-9800-03.jpg

    This picture was taken with the slider knobs installed.

    PioneerSG-9800-04.jpg

    And this one with the overhead light turned on.

    PioneerSG-9800-05.jpg

    Lee.
     
    Last edited: Jan 23, 2017
    SofaKing likes this.
  2. Skylab

    Skylab Altimeter reading zero Subscriber

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    Looks great!!!! I have an SG-9800 - nice to know the LEDs can not only be replaced but upgraded ;)
     
  3. CarnahanBB

    CarnahanBB Super Member

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    Dang! That sucker looks sweet! Nice work!
     
  4. 1TUFSS

    1TUFSS Thread Killer

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    Good stuff!
     
  5. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    Here is a list of the parts to re-cap this equalizer. If you cut and paste this into Notepad, Wordpad or similar text editor, but save it with the extension CSV, you should be able to import it into Excel.

    I have included the LED part numbers as well, along with the op-amp replacements. If you're feeling brave, you could try some op-amp rolling on this EQ, but with 26 of them, that's quite a BIG roll. You'd have to adapt something in place of the 1452W's.

    Lee.

    Pioneer SG-9800 caps,,,,,,

    C,C,uF,V,Notes / upgrade,Voltage if different,Mouser part number
    201,202,10,25,LL,35,647-UKL1V100KDDANA
    203,204,10,25,LL,35,647-UKL1V100KDDANA
    213,214,47,16,,25,647-UKW1E470MDD
    607,608,10,25,LL,35,647-UKL1V100KDDANA
    802,,330,10,,16,647-UKW1C331MPD
    803,,1,50,,,647-UKW1H010MDD
    903,904,1000,35,,,647-UKW1V102MHD
    909,,100,10,,16,647-UKW1C101MDD
    910,911,10,16,,50,647-UKW1H100MDD
    912,913,470,16,,,647-UKW1C471MPD

    ,,,Qty,,,
    2x5mm LED,,,24,,,604-WP113SRDT
    5mm hi bright red LED,,,2,,,604-WP7113SRD14V
    5mm hi bright yellow LED,,,1,,,696-SSL-LX5093SYD
    ,,,,,,
    4558DX opamps (22) replace with OP2134,,,,,,
    Hitachi 1452W opamps (4),,,,,,
     
    Last edited: May 28, 2013
  6. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    Here is a picture of the re-capped board, around by the power supply area.

    PioneerSG-9800-06.jpg

    And here is the front. Notice the one switch in the foreground, and the two hidden under the ribbon cable, these are the ones I replaced.

    PioneerSG-9800-07.jpg
     
    Last edited: Jan 23, 2017
  7. day67

    day67 Super Member

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    Great pics! Thanks Leesonic. Caps list will come in handy
     
  8. kevin_09

    kevin_09 New Member

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  9. Tangerine

    Tangerine Thanks for all the fish!

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    Lee,

    Thanks fo
    r the hard work you've put in with refurbing your SG-9800. I'm keen to see the pics that were originally posted here, but they aren;t available any more. Do you still have them at hand?

    Cheers,

    Les.
     
  10. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    Fixed broken picture links.
     
    Tangerine likes this.
  11. jvinhj240

    jvinhj240 Member

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    how big sound improvement after upgrades? are they easy to replace for newbie?
     
  12. Mike66202

    Mike66202 New Member

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    Nice post. Thanks for the information. I have one of these and tried to replace the led's with these blue ones:
    http://www.ebay.com/itm/100pcs-2x3x...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649
    I saw a u-tube of a guy actually got his to work, but when I tried it...all went well for the first 4 or 5 then the led's got progressively dimmer. I kept going until all were replaced on the left side and they were BARELY visible at all.
    All the sliders were cleaned with faderlube f5 then a application of faderlube f100. So, I replaced all the blues with the oroginals and they are all nice and bright again...just red. Sounds great....but no joy with the blue led's
    Obviously, something is wrong here. Could anyone help with this?
    The look of the blue led's are a way nicer match with my sr-303 and ct-f900.

    Thanks
    Mike
     
  13. leesonic

    leesonic Hold on, here comes the bass. Subscriber

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    Hi Mike,

    I bet your problem is the forward voltage drop of the blue LEDs versus the red ones. Without looking at the schematic (because I don't have it to hand), I would guess the LEDs are wired in series, which is the best way to drive them, as LEDs do strange things in parallel. So, if you have 10 LEDs that have a forward voltage drop of 2v, you can connect them all in series across a 20v power supply. Now, if you try the same with blue LEDs, which typically have a voltage drop of 3v, you're going to run out of voltage pretty quick. It MAY be possible to split the single banks of 10 LEDs into two banks of five (or four banks of five if you could both channels), and use dropper resistors if necessary.

    Lee.
     
  14. Mike66202

    Mike66202 New Member

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    Location:
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    Hi...yes...what you're saying makes sense to me (in my VERY limited understanding) however...not being educated enough to tackle that...I think I'd be better off leaving them red.
    What i simply cannot understand, is, how kevin_09 (in this thread....see above) pulled it off by simply swapping the led's.
    Here is his video...
    Even I think I could tackle this.
     

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