919

Discussion in 'Exclusively Sansui' started by Willy6, Aug 17, 2017.

  1. Willy6

    Willy6 AK Subscriber Subscriber

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  2. Willy6

    Willy6 AK Subscriber Subscriber

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    Perhaps two ksc1845's with their emitters soldered together would work?And two ksa992's vice versa.
     
  3. Willy6

    Willy6 AK Subscriber Subscriber

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    Some on eBay for 10 bucks each
     
  4. Willy6

    Willy6 AK Subscriber Subscriber

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    Yep I confess it was all my fault I put those capacitors in backwards the way the silkscreen shows them to go and smoked a resistor with the DBT it lit up and I left it on to long R01 went up in smoke i checked almost everything else accept tr05 which I was hoping was still good and I was dead wrong tr05 is fried thanks to me relying on the silkscreen print out..
     
  5. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    I am sorry to see you are still having difficulties Willy, but at least you are making progress. :thumbsup: The back-to-front capacitor markings on the F-2844 (small PSU) are a real pain in the backside. It caught me out first time around - luckily that was my own '919, and photographs revealed the error. Perhaps it is time for a reminder of an often forgotten standard procedure, 'when fault finding always check PSU voltages first'. - keep going. :)
     
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  6. Ronito6

    Ronito6 Super Member

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    Those are G rank so it's best to keep your new ones the same.

    You are lucky, those are still easy to find. Hope they are the missing piece to you 919 puzzle.
     
  7. Willy6

    Willy6 AK Subscriber Subscriber

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  8. Willy6

    Willy6 AK Subscriber Subscriber

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    It's the only thing wrong that I can find as everything else I was able to adjust and the voltage on the good side of tr05 measured a perfect 57v the bad side measured .625v the voltage on tr06 measures a perfect -57 on one side and -40 on the other side.
     
  9. Willy6

    Willy6 AK Subscriber Subscriber

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    And I also found out not to completely trust the DBT if the bulb stays lit for more then a few seconds turn it off or you risk frying something.I only work on my own stuff so no big deal I think I already found the right parts so this thing should be up and running soon .Thank You for all the input I know I can be a pain in the @$$ sometimes
     
  10. Willy6

    Willy6 AK Subscriber Subscriber

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    Well I received the used replacement 2sc2259 npn dual transistor from eBay for about $15 including shipping and to my surprise it tested good on one side and a diode junction on the other side so feeling a little frustrated I compared the good side readings on my peak tester to that of a new 2sc1845 and they were pretty close to the same so i soldered the emitters of two 2sc1845s together and put it in place and now I'm getting +44v on pin 4 and -39.5v on pin 6 the schematic calls for +/- 40v on pin4 and pin6 I then flipped the unit over and adjusted f-2833 to a perfect +/- 10v on both channels.My question is should I try to find another 2sc2259 or leave the two 2sc1845s in place?
     
  11. Overundr1

    Overundr1 AK Subscriber Subscriber

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    gain match two 1845's, heat shrink them together with just a dab of thermal grease, install and forget. I too have had less than stellar results with 2259's.
    -Lee
     
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  12. Willy6

    Willy6 AK Subscriber Subscriber

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    Do you think I should try to lower the+44v on pin 4 with a smaller resistor or just run it this way?All of the adjustable voltages are right on the money now and I played it for 3 or 4 hours last night with no problems..Sounds awesome by the way.
     
  13. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    I wouldn't worry about it too much, the regulator is definitely working (regulating) - and if all the other settings can be achieved (you say they can) then you are good to go - Well Done Willy! :thumbsup:

    If you were determined to tweak it, you could first check the ZD01 zener voltage (just measure across the zener), and maybe change the zener for one closer to 24V if it is 'out'. If this is not the case then you could make small changes to the ratio/values of R15 and R14 (keeping the sum of their values the same). - this will finely adjust both the positive and the negative regulators.
     
    Last edited: Nov 12, 2017
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  14. Willy6

    Willy6 AK Subscriber Subscriber

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    The only thing I didn't adjust is the balance on F-2833 and I set those to the center positions.
     
  15. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    Yes, for that adjustment you need a very low output signal generator and a distortion analyser. :thumbsup:
     
  16. Willy6

    Willy6 AK Subscriber Subscriber

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    I have a signal generator now I need to buy a distortion analyser I guess then I need to take a class on how to use all this stuff
     
  17. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    :thumbsup::thumbsup::thumbsup:
     
  18. Willy6

    Willy6 AK Subscriber Subscriber

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    Got 24 hours off for a change and decided to cut the 919 loose among other things.Been playing cds at different volumes for about 4 hours now and it hasn't missed a beat paired with some Klipsch KLF-30S and Klipsch chorus-1s sounds pretty damn good the forte's on the outside didn't make the cut so I'm saving those for the AU-999.. 20171114_213430.jpg 20171114_213448.jpg
     
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  19. Ronito6

    Ronito6 Super Member

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    Good work that!!

    [​IMG]
     
  20. Willy6

    Willy6 AK Subscriber Subscriber

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    No I bumbled through it and didnt pay attention to the great Lee stereos thread and basically fu#$ed the power supply up when I relied on the silk screen print out and put those caps in back@$$words..
     
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