The Rice Krispies is audible IN THE ROOM. That is to say, it's not specifically in the audio circuit, it's something that can be heard with no audio, headphones or otherwise, hooked up. The machine is physically making the noise. It is faint, but present. It is accompanied by flickering VU meter lights until, after 3-5 seconds, everything stabilises. My Spidey Sense tells me a capacitor is malfunctioning somewhere in the startup circuit downstream from the power supply board and sputtering until it finally charges.
There is a fairly loud hum in the headphone amp circuit. If I deselect the channels (1-4) feeding the headphones, the hum goes away. It is a separate issue from the noise at startup. Which brings me to:
There are 33 electrolytic caps on the MONITOR AMP PCB. It is readily accessible and I was wondering about shotgunning those while the panels are still off the machine. They are also 40 years old and there's a ton of them. Couldn't hurt and it's an easy job. That would probably clean up a lot of stray and, as yet undetected, leaky wonkiness in the audio chain.
Anyway, these are my musings. Please comment and correct where necessary. This is more than I ever wanted to do but, in for a dime, in for a dollar...
