Ive got a BSR eq3000 equalizer here that recently developed a random crackling/static noise in the right channel. it only happens if the EQ button is pressed and the equalizer is ON. if i disable the equalizer the crackling stops.
the crackling is 100% completely random and happens with or without an audio source. it will happen after being on for minutes or hours or days, it doesnt matter. movement and whatnot dont effect it. any ideas on what it could be? ive grown rather fond of this EQ and id like to get it back in service again.
the crackling is 100% completely random and happens with or without an audio source. it will happen after being on for minutes or hours or days, it doesnt matter. movement and whatnot dont effect it. any ideas on what it could be? ive grown rather fond of this EQ and id like to get it back in service again.
Noisy component, probably a semiconductor, though other components can also become noisy.
You can already isolated it to the EQ section itself. Good. Now turn all the sliders down, but max them one at a time or in groups of just a few, and wait. What we are looking for is whether the noise seems related to just one or a few of the EQ bands, or if it is overall and matters not what the individual bands are doing. There will be circuit stages before the EQ, in the EQ itself, and after. If the noise comes from before, then all bands will affect the noise. If the noise comes from after the EQ< then none of the bands will affect the noise. And if only some EQ bands affect the noise, that narrows it down to a freq band circuit. I don't know this unit, but I assume an op amp stage for each EQ band?
Get out the scope, and watch the output pins of the ICs in that section. No input signal, since the symptom occurs without it anyway. Signal would just serve to mask the symptom. Now turn up the scope gain, and look for the noise signal.
You can already isolated it to the EQ section itself. Good. Now turn all the sliders down, but max them one at a time or in groups of just a few, and wait. What we are looking for is whether the noise seems related to just one or a few of the EQ bands, or if it is overall and matters not what the individual bands are doing. There will be circuit stages before the EQ, in the EQ itself, and after. If the noise comes from before, then all bands will affect the noise. If the noise comes from after the EQ< then none of the bands will affect the noise. And if only some EQ bands affect the noise, that narrows it down to a freq band circuit. I don't know this unit, but I assume an op amp stage for each EQ band?
Get out the scope, and watch the output pins of the ICs in that section. No input signal, since the symptom occurs without it anyway. Signal would just serve to mask the symptom. Now turn up the scope gain, and look for the noise signal.
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