I've got a pair for M-Audio BX8's the original ones from 2002. https://img.audiofanzine.com/images/u/product/normal/m-audio-bx8-3304.jpg
So I've been trying to solve this problem forever and put in on hold many times over a few years, I've done everything I can think of and nothing seems to solve the problem.
I thought it may be bad caps or and it may be but I've tired different caps with no luck, It seems the problem I've narrowed down is for now with the toroidal transformer making the tweeter side of the amp pick up hum/buzz from the mounting plate.
I own two of these from the same year 2002 in the same line of monitors, so I've been using the good one to compare, I thought it might be a grounding problem and it might be, so I added grounding to places missing on the unit with the tweeter hum/buzzing problem and while I did manage to make it match in terms of where the ground should lead to, testing the points on the board where it should've had ground and didn't before are fixed. It could be some kind of ground loop or something but I am not sure.
Here's the important bit, if I move the transformer away from the casing it's normally attached too the humming/buzzing goes from audible buzzing in the listening position, back down to normal levels of noise, gentle static if you put your ear up to it just like the good unit.
If anyone knows what may be causing that hum to come back only when it comes closer to the plate it's normally attached to it would be a big help.
I'll put some photo's to help clarify but if all else fails I may just have to leave it disconnected form the case when installing it back into the speaker box since it works fine other than the very annoying loud humming coming out of the tweeter when connected to the case.
I put some photo's and a similar schematic down below, I can add more if needed of the boards in detail if needed.
So I've been trying to solve this problem forever and put in on hold many times over a few years, I've done everything I can think of and nothing seems to solve the problem.
I thought it may be bad caps or and it may be but I've tired different caps with no luck, It seems the problem I've narrowed down is for now with the toroidal transformer making the tweeter side of the amp pick up hum/buzz from the mounting plate.
I own two of these from the same year 2002 in the same line of monitors, so I've been using the good one to compare, I thought it might be a grounding problem and it might be, so I added grounding to places missing on the unit with the tweeter hum/buzzing problem and while I did manage to make it match in terms of where the ground should lead to, testing the points on the board where it should've had ground and didn't before are fixed. It could be some kind of ground loop or something but I am not sure.
Here's the important bit, if I move the transformer away from the casing it's normally attached too the humming/buzzing goes from audible buzzing in the listening position, back down to normal levels of noise, gentle static if you put your ear up to it just like the good unit.
If anyone knows what may be causing that hum to come back only when it comes closer to the plate it's normally attached to it would be a big help.
I'll put some photo's to help clarify but if all else fails I may just have to leave it disconnected form the case when installing it back into the speaker box since it works fine other than the very annoying loud humming coming out of the tweeter when connected to the case.
I put some photo's and a similar schematic down below, I can add more if needed of the boards in detail if needed.
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