Thanks a lot. I noticed that too while I was inspecting these boards, "hmm, weird jumper wire here." Is it advisable to add a resistor there? If so, is it a 10ohm 220ma as shown?
I would (re)install a fusible resistor. In theory that would be a 0.5W, and so I did replace it once by new one during a full rebuilt. Yet...a few months later it blew when a happy kid found it amusing to flip the power on-off switch multiple times very quickly.....and that resistor blew.... loosing the -90V rail to the input stages of the power amp PCBs. As such I can imagine that somebody put a jumper in, but it also exposes the capacitor in series with it (the orange one) to a higher operating voltage
It seems that the original white ceramic fusible resistors have much more peak current tolerance than new ones. So for a modern replacement I would resort to a 1W non-flammable type. That is always better than a jumper.
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