P800

P800 power supply board rebuild #

Original power supply was in decent shape, but I noticed some traces of overheating on PCB. Besides, that due to component shortage right now it is not always possible to buy a component of required size. For example like those double diodes for rectification: H808, H811. What package is it? I find it inconvenient to bend leads for TO-220 to put into these holes. And of course i wanted a black color since every possible part inside is black. Not that it affects sound quality…. but esthetics :)

Part list #

Parts list i used is below. As you can see almost all components are replaced on modern one.

  1. C801 - Original 220uF 63v / 470uF 63v ( EKY-630ELL471MK25S)
  2. C802 - Original 100uF 50v / 220uF 50v (EKYA500ELL221MJ16S)
  3. C803 - Original 0.01uF 50V / (PFR5103J63J12L4BULK )
  4. C804 - Original 22uF 35v / 22uF 50v (EKY-500ETD220ME11D)
  5. C805 - Original 330uF 50v / 680 50v (EKZE500ELL681MK30S)
  6. C806 - Original 470uF 16v / 470uF 25v (EKY-250ETC471MH20D)
  7. C807 - Original 4.7uF 50v / 10uF 50v (EKY-500ELL100ME11D)
  8. C808 - Original 47uF 16v / 47uF 25v (EKY-250ELL470ME11D)
  9. C809 - Original 220uF 10v / 220uF 50v (EKYA500ELL221MJ16S)
  10. H801 – Original 2SD330 / MJE15028G
  11. H802 – Original 2SC1318 / KSC2383YTA
  12. H803 – Original 2SC945 / KSC2383 YTA
  13. H804 – Original 2SD331 / MJE15028G
  14. H805 – Original 2SC945 / KSCR2383YTA
  15. H806 – Original 2SC1318 / KSC2383YTA
  16. H807 – Original 2SC1318 / KSC2383YTA
  17. H808 - Original DS131B / Dual Diode (BYQ28E-200,127)
  18. H809 - Original WZ-071 / 1N4737A
  19. H810 - Original WZ-014 / 1N5244B
  20. H811 - Original DS131B / Dual Diode (BYQ28E-200,127)
  21. H812 - Original 1S2471/ 1N4148
  22. L801 - MY2Z-02-DC22 relay / MY2-020DC24 (MY2-02DC24)
  23. R801 - 33 Ohm 1/2W flameproof
  24. R807 - 150 Ohm 5 watt / 150 ohm 7 watt (W221500JRLF)
  25. R815 - 560 Ohm 2W (RR02J560RTB)

I also replaced R801 which is 33 Ohm flameproof. R801, R807 and R815 must be on the long leads for better cooling.

Resistors and diodes can be reused as is. Transistors has the same pinout. Here is the list of packages used for capacitors:

  1. C801 - Radial_D12.5mm_P7.50mm
  2. C802 - Radial_D10.0mm_P5.00mm
  3. C803 - Rect_L7.5mm_W6.5mm_P5.00mm
  4. C804 - Radial_D5.0mm_P2.50mm
  5. C805 - Radial_D12.5mm_P7.50mm
  6. C806 - Radial_D8.0mm_P5.00mm
  7. C807 - Radial_D5.0mm_P2.50mm
  8. C808 - Radial_D5.0mm_P2.50mm
  9. C810 - Disc_D12.0mm_W4.4mm_P7.75mm

Design process #

Initially I had to draw it on the paper. I measured all the sizes using caliper. It didn’t went exactly well in the first go, but did in second.

When design is done I usually print the board silk and traces at 1:1 scale like on the image bellow:

Look at physical prints usually helps to find inconsistencies and mistakes.

When board was finally manufactured (Rev.A bellow) it looked like this:

Final look #

In order to assemble it right we need to follow quite a few simple steps and result should be like this:

Want to order? #

If you want to order, let me know (email @ bitomaxsp on google) . I have a small stock of these. Price is 10$ per PCB, plus shipping. I can ship as a letter which would be the cheapest option (around 3-4 USD) or as a letter with tracking which will be ~14 USD. I personally hate to pay for the delivery more than the actual goods price. But I don’t set shipping cost so… Good luck.

Calendar November 27, 2021