Model Eleven Power Supply Re-cap????

[racfan9]

Hey Guy's and Gal's....I'm getting ready to rebuild the power supply for my Model Eleven so I have few questions for all you experts.
I'm replacing all caps and resistors on the board so should I run with the same values on the caps? Also what about the five diodes, should I replace? I'll leave the 2sc1419 as is.

Thanks,
racfan9

 

[UncleBingo]

If you can find them- you may have to go up in UF as the nominal values may have changed (for example, 30uf has been standardized to 33uf). There may be a huge price difference between the original value cap and a newer nominal value capacitor. Use the search tool at say Mouser or Digikey if you aren't sure. Voltage always the same or higher. Sometimes higher voltage cap will be a better fit than a modern similar voltage cap as caps have shrunk in physical size/capacity.

 

[racfan9]

What about the 4 mylar 0.1uf, should they also be replaced?

 

[dstariha]

There has been some discussion about inrush current damaging the power switch if one uses higher value filter caps. There has also been a neat fix by installing a thyristor circuit to avoid this event. You may want to also save the old caps and drill them out so they can be used as covers for the new, probably smaller caps. That way mounting the new caps is simple and will retain the original "look".
You can search this forum for these articles. My recommendation is to use the highest "audio quality" caps you can, they are not that much more expensive in the quantities you need.
Have fun and enjoy the music.

 

[UncleBingo]

What about the 4 mylar 0.1uf, should they also be replaced?

I wouldn't. Unless they're bad.

 

[SicMan]

Power supplies don't need high grade audio caps.
Also replace the transistors to newer ones. The old ones, especially in the power section degrade faster with the heat.
Use the high grade audio caps in the audio path and amp section.

My .02
been there done that on many units

John M