The mic in question is a Boya BY-M1000/Movo VSM-7 Multipattern condenser, obviously can't compare to some of the top microphones around, but for the value proposition (got a pair of this for less than USD90 from my country Malaysia) & as my learning tool to various mic recording techniques, this thing's hard to beat, though I wished it will have just a tad more sensitivity/headroom, A little backstory of what happened: I opened up one of the microphone a couple weeks back to see the circuit, and decided to try changing the bigger capacitor to see how it will alter the sound. First time I did, accidentally broke the solder joint between back diaphragm & pattern switching circuit. OK, I figured, its no big deal, easy to solder back, and I decided to extend the wires while I'm at it. Assembled it back, and the cardioid mode now in bi-directional mode (I'm guessing the back diaphragm was not grounded/opened properly during switch), and I proceed to open back up to try and resolder the capsule's wirings again.
THEN now this is the first time circuit board fell onto the floor along with the kind of heavy XLR output shell after I disconnected the diaphragms wiring. I probed the component connections (except for the SMDs), doesn't look like there's any significant damage, and I figured I might as well try swapping out the 50V DC capacitor while I'm at it. This thing's hard to remove, and I think I left my solder on the circuit board for more than half a min at times just to melt the tin and suction it out (the remainder tin inside I attempted to use a thin drillbit to punch a hole, I messed this joint's direct connection to GRD on the circuit, so I wired an extra connection for the capacitor to go to Ground). Also accidentally removed the R11 SMD resistor (think its a 6.8k resistor.. I measured 6.5k+) in the meanwhile and proceed to lose it. : ( Circuit fell another time just as I was done soldering a new cap. Replaced the lost R11 with 2 series resistor, and wired everything back.
I must have damaged the circuit board quite badly because now when I plug it back in, I hear nothing but random sputters & farts, some kind of short oscillating tone sometimes, & if I crank the gain high up I will get white noise here. Switches does absolutely nothing, and the low cut switch will occasionally pop if i switch it back and forth.
TLDR: Got greedy & attempt to mess with the Multipattern mic's circuit, and proceeded to screw up badly & killed the circuit. But the shell & diaphragm (3 wire LDC) is totally fine, not sure about the switches.
Anyway, since I'm already at this stage (I had other DIY projects planned besides my current mic booster mod), I figured I might as well attempt some options below while I try to understand the circuit, just need opinions:
Option 1: Attempt to repair & study the circuit. I'm starting to dislike SMD components due to my lack of skills at handling tiny components like these, and I can't quite tell at first glance what's the circuit based on. From what I have read so far, LDC mics are supposed to be polarized by the circuit, and the pattern switching is done by either by polarizing the backplate with +/- DC voltage or leaving it open (was looking at one of Neumann's multipattern circuit). However, in my probe the switching seems to do something a little bit more complicated, and I suspect the LDC's not being polarized with enough voltage to begin with (maybe that explains the sensitivity issue)
Option 2: Replace the circuit completely. I have access to Aliexpress where I live, so ordering budget replacement circuits is fairly easy (quality concerns aside). But I'll need to modify the circuit a little so that I can retain the pad switching & the low cut switching. But I might change the pattern switching to just retain Cardioid & figure 8 pattern as I don't have much use for the omni pattern. I'm also thinking maybe a DIY circuit kit is a good idea, since I can learn how to assemble a circuit from the ground up, but I'm limited by the spacing inside this shell (I can either mount a thin PCB of about 30mm*52mm, or roughly just above 40mm by 45mm). Maybe I'll need to rehouse the capsule & switches to another body/shell, and repurpose the original body for other uses.
So yea, shoot me, point me to a place where I may be able to source for good quality kits/parts, or laugh at me all you want. Learned my lesson of don't fix things if they ain't broken, I'm open to any feedbacks at this time. Pics of the mic in attachment.
THEN now this is the first time circuit board fell onto the floor along with the kind of heavy XLR output shell after I disconnected the diaphragms wiring. I probed the component connections (except for the SMDs), doesn't look like there's any significant damage, and I figured I might as well try swapping out the 50V DC capacitor while I'm at it. This thing's hard to remove, and I think I left my solder on the circuit board for more than half a min at times just to melt the tin and suction it out (the remainder tin inside I attempted to use a thin drillbit to punch a hole, I messed this joint's direct connection to GRD on the circuit, so I wired an extra connection for the capacitor to go to Ground). Also accidentally removed the R11 SMD resistor (think its a 6.8k resistor.. I measured 6.5k+) in the meanwhile and proceed to lose it. : ( Circuit fell another time just as I was done soldering a new cap. Replaced the lost R11 with 2 series resistor, and wired everything back.
I must have damaged the circuit board quite badly because now when I plug it back in, I hear nothing but random sputters & farts, some kind of short oscillating tone sometimes, & if I crank the gain high up I will get white noise here. Switches does absolutely nothing, and the low cut switch will occasionally pop if i switch it back and forth.
TLDR: Got greedy & attempt to mess with the Multipattern mic's circuit, and proceeded to screw up badly & killed the circuit. But the shell & diaphragm (3 wire LDC) is totally fine, not sure about the switches.
Anyway, since I'm already at this stage (I had other DIY projects planned besides my current mic booster mod), I figured I might as well attempt some options below while I try to understand the circuit, just need opinions:
Option 1: Attempt to repair & study the circuit. I'm starting to dislike SMD components due to my lack of skills at handling tiny components like these, and I can't quite tell at first glance what's the circuit based on. From what I have read so far, LDC mics are supposed to be polarized by the circuit, and the pattern switching is done by either by polarizing the backplate with +/- DC voltage or leaving it open (was looking at one of Neumann's multipattern circuit). However, in my probe the switching seems to do something a little bit more complicated, and I suspect the LDC's not being polarized with enough voltage to begin with (maybe that explains the sensitivity issue)
Option 2: Replace the circuit completely. I have access to Aliexpress where I live, so ordering budget replacement circuits is fairly easy (quality concerns aside). But I'll need to modify the circuit a little so that I can retain the pad switching & the low cut switching. But I might change the pattern switching to just retain Cardioid & figure 8 pattern as I don't have much use for the omni pattern. I'm also thinking maybe a DIY circuit kit is a good idea, since I can learn how to assemble a circuit from the ground up, but I'm limited by the spacing inside this shell (I can either mount a thin PCB of about 30mm*52mm, or roughly just above 40mm by 45mm). Maybe I'll need to rehouse the capsule & switches to another body/shell, and repurpose the original body for other uses.
So yea, shoot me, point me to a place where I may be able to source for good quality kits/parts, or laugh at me all you want. Learned my lesson of don't fix things if they ain't broken, I'm open to any feedbacks at this time. Pics of the mic in attachment.
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