A "crack" or "pop" sound from the spekaer at power-on isn't uncommon on some models of Acorn - my rack-mounted A4000 does it on power-on and switch-off. It's just an oddity of the hardware, the voltages in the circuit coming up and equalising. Thing is I wouldn't call it loud on mine -- I have the volume set to "Loud" in !Configure, and the power-on beep is much louder than the pop.Bumping this thread! I have an A4000 with exactly the same problem (a very loud crackle out of the speaker as soon as the machine is turned on), which persists after recapping the SMD caps and cleaning the headphone jack.
Whilst this is no doubt shotgunning, I've removed the audio hybrid and soldered in Harwin headers as suggested earlier in the thread - without a noticeable improvement, indicating it's not a dry joint or similar. I'm now thinking (see, I told you I was shotgunning) of replacing both the opamp and the transistors on the hybrid, in the belief that it's not the caps. However, it's not clear to me that anyone with a similar problem ever root-caused it - can someone let me know if they've fixed the issue by swapping parts?
Statistics: Posted by philpem — Sat Jan 04, 2025 10:40 pm