STK-0050 replacement for SX-780 and others

Discussion in 'Pioneer Audio' started by rcs16, Jun 18, 2016.

  1. clayyea

    clayyea New Member

    Messages:
    1
    Will these work for the STK0039 in the SX-680?
     
  2. Bassblaster

    Bassblaster Super Member

    Messages:
    1,690
    Location:
    Cambridge, Ohio
    Possibly, They have the same pinout but the internal circuit is different. would need someone with more knowledge than me to chip in on that
    upload_2017-8-6_15-22-29.png
     
    Pio1980 likes this.
  3. zebulon1

    zebulon1 This summer heat slowed me down. Subscriber

    Messages:
    3,916
    Location:
    Las Vegas Nevada
    It should work
     
  4. rcs16

    rcs16 Super Member

    Messages:
    2,850
    Location:
    Baldwin, Ontario, Canada
    STK0039 is a quasi-complementary darlington config and the STK0050 is a 2 stage emitter follower. Both require about the same amount of bias
    I'd have to simulate the design to determine if current through the bias generator is correct to get the bias for o/p stage correct.
    If you try the circuit out, measure the ops bias current to see if you can get what is required.
     
    merlynski likes this.
  5. MichaelFin

    MichaelFin New Member

    Messages:
    9
  6. Bassblaster

    Bassblaster Super Member

    Messages:
    1,690
    Location:
    Cambridge, Ohio
  7. MichaelFin

    MichaelFin New Member

    Messages:
    9
    Thank you so much! I got my PCB and shields and ordered all the components, here's to hoping it fixes my issue.
     
  8. rcs16

    rcs16 Super Member

    Messages:
    2,850
    Location:
    Baldwin, Ontario, Canada
    There is also 863-NJW0302G and 863-NJW0281G which are a bit cheaper than 2SA1962OTU / 2SC5242OTU and a bit more power.
    Also Toshiba 2SA1943N/2SC5200N but 2SC5200N is on back order at this time too.
    Good thing we have lots of choices available.
    All should work fine.
    Lets hope that this will fix the problem without further troubleshooting.

    On another note, a previous post stated that they had some difficulty with getting the position of the bjt mounting holes to lead bend distance correct.
    I use a ink marker to mark the spot on the leads to indicate the bend point. I use the pkg mounting screw to temp place the pkg in position to mark the spot as it is placed on the HS. then bend the leads with needle nose pliers, place pliers just slightly in front of the bend point. last op is to solder the pins to the pcb after insulators are in place and device is torqued down after you have mounted the pkg to the HS.
     
    Last edited: Sep 3, 2017
    merlynski and Bassblaster like this.
  9. tsd71

    tsd71 Gittin Some Head!

    Messages:
    2,660
    Location:
    New Jersey
    What gauge wire are we using ffrom the module to the board on this replacement? 20-22?
     
  10. merlynski

    merlynski Curmudgeon Electronicist Subscriber

    Messages:
    82
    Location:
    High Plains, Eastern Colorado
    I plan on using 18 AWG tinned solid for +/- power and output leads and 22 AWG tinned solid for others.

    EDIT: According to https://www.powerstream.com/Wire_Size.htm !8 AWG is good to 16 amps and 22 AWG is good to 7 amps when used for chassis wiring.
     
    Last edited: Sep 14, 2017 at 11:20 PM
  11. Bassblaster

    Bassblaster Super Member

    Messages:
    1,690
    Location:
    Cambridge, Ohio
    Heads up, the MJE15032G is backordered untill feb 2018. check rcs16's post for subs. MJE15030G is due back in tomorrow.
     
  12. MichaelFin

    MichaelFin New Member

    Messages:
    9
    I just want to make sure I'm not mistaken. It doesn't matter if I use a PNP vs a NPN for this specific circuit correct?
     
  13. redk9258

    redk9258 Super Member

    Messages:
    1,015
    Location:
    Illinois, close to St. Louis.
    Incorrect! You can NEVER intermix PNP / NPN.
     
  14. MichaelFin

    MichaelFin New Member

    Messages:
    9
    Well shoot. The original Q4 from the BOM (http://www.mouser.com/Search/ProductDetail.aspx?R=NJW3281Gvirtualkey58410000virtualkey863-NJW3281G) is an NPN and I ordered PNP (http://www.mouser.com/Search/Produc...OTUvirtualkey51210000virtualkey512-2SA1962OTU) as a replacement. I guess I could have checked that better myself.

    I ordered the NPN.

    Is there a reason people listed the PNP/NPN options when Q4 was only an NPN? I'm curious.
     
  15. rcs16

    rcs16 Super Member

    Messages:
    2,850
    Location:
    Baldwin, Ontario, Canada
    That is because you should match up true complementary pairs for drivers and/or outputs. For example you should not use a Toshiba with a Onsemi or Fairchild npn/pnp pair as drivers nor o/p. It is okay to use a Toshiba pair as drivers and Fairchild pairs for o/p.
    Certainly does not hurt to post your order here so that others can review what you are up too b4 you place the order.
     
  16. MichaelFin

    MichaelFin New Member

    Messages:
    9
    Ah, this makes sense. I understand now. Thank you!
    Q1:[NJW1302G](http://www.mouser.com/Search/ProductDetail.aspx?R=NJW1302Gvirtualkey58410000virtualkey863-NJW1302G_
    Q2: [MJE15032G](http://www.newark.com/on-semiconduc...DGSGrOU4V5IcxN_cTHPV5GHd4Xx4haEUaArmDEALw_wcB)
    Q3:[2SA1962OTU](http://www.mouser.com/Search/Produc...OTUvirtualkey51210000virtualkey512-2SA1962OTU)
    Q4:[2SC542OTU](http://www.mouser.com/search/ProductDetail.aspx?r=512-2SC5242OTU)

    Everything else is directly off of the BOM from the first page.

    https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=50f7dd2519

    I'm guessing my Q3/Q4 pair is okay, not sure about Q1/Q2. I don't know why the original Q1 isn't showing up on the BOM link like I thought it used to.
     
  17. rcs16

    rcs16 Super Member

    Messages:
    2,850
    Location:
    Baldwin, Ontario, Canada
    Above is incorrect
    For Q1, use 863-NJW0302G (pnp) [You can sub 512-2SA1962OTU, but must use it with 512-2SC5242OTU]
    For Q2, use 863-MJE15031G (npn)
    For Q3, use 863-MJE15030G (pnp)
    For Q4, use 863-NJW0281G (npn) [You can sub
    512-2SC5242OTU, but must use it with 512-2SA1962OTU]
    All are in stock at Mouser as of today, Sept13,2017
     
  18. MichaelFin

    MichaelFin New Member

    Messages:
    9
    Thank you so much! Hopefully by the end of next week I'll have soldered them on alright and can test them out.

    Thank you again, I appreciate it.
     
  19. tsd71

    tsd71 Gittin Some Head!

    Messages:
    2,660
    Location:
    New Jersey
    rcs, I have a question, on your Mouser BOM you have R2 listed as a 75ohm 1/2 watt resistor, but in your PDF from page 1 you have R2 listed as a 1K ohm 1/2 watt resistor. which is the correct resistor?

    Mouser.jpg PDF.jpg
     
  20. zebulon1

    zebulon1 This summer heat slowed me down. Subscriber

    Messages:
    3,916
    Location:
    Las Vegas Nevada
    I've used the 75, 1/2 watt with success.
     

Share This Page