07-06-2012, 06:46 PM
I believe we had the same case of missing dot here in this forum, from exact same cap, a couple of months ago.
There SHOULD be a tiedot between the wire from the right #50 8uF cap to #28 resistor, and the crossing wire from the top side of the field coil and left bottom pin of the output xfmr.
If you did not wire the cap after recapping back when it was, this can be the reason of your squealing, you have a positive feedback and ocillation using xfmr and the tone control caps as resonant tank, turning the output stage into an oscillator. Actually this is why I asked about this cap after your question about squealing. So I would check this before changing value of that 0.002uF cap.
If the cap is there, then it is something else.
There SHOULD be a tiedot between the wire from the right #50 8uF cap to #28 resistor, and the crossing wire from the top side of the field coil and left bottom pin of the output xfmr.
If you did not wire the cap after recapping back when it was, this can be the reason of your squealing, you have a positive feedback and ocillation using xfmr and the tone control caps as resonant tank, turning the output stage into an oscillator. Actually this is why I asked about this cap after your question about squealing. So I would check this before changing value of that 0.002uF cap.
If the cap is there, then it is something else.
