AU-919 Caps on back of Control Amp.

[Engels13]

Looking at a AU-919 restore I noticed the pf caps on the back of the control amp board. I don't have these on my 919 control amp board. Why are they there and do they need to be there?

 

[skippy124]

Hi,

That looks like the Flat Amp F-2841.

Those capacitors go from the collector to the base of several transistors on thiw board, and are fitted I beleive for stability purposes (prevent parasitic oscillations occuring). My bet is that the pictures are showing an early manufacured unit, where the caps have been fitted on after the board design was complete - a production line mod which occurs in many Sansui and other vintage gear. Your unit may be a later production run where the board design was changed to accommodate the caps mounted from the component side. The service manual I have for the 919 shows these capacitors fitted to the component side of the board.

Cheers

John

 

[Engels13]

Many thanks for the explanation John. Good to know, thought I forgot something after all the work on it.

 

[ghamilton]

My 919 doesn't have them on the back as in the photos.

 

[Helios]

Nor mine; built in 1979.


Helios

 

[Engels13]

Got it from this side:
http://s694.photobucket.com/albums/vv306/scottrt/Sansui AU-919 restoration/?start=all