Hey there,
I'm new to the group and I would like to contribute something I've been working on and off in the last couple of weeks.
I randomly came across the BM-700/800 cheap chinese SDC mods using the Alice circuit and I really liked the idea as well as the result, getting a microphone worth around 400€ for less than 100€ is no joke; but I didn't like that altough most mods described how to change the high pass frequency (to tame the proximity effect) and some even implemented a low pass (to tame some shrill in the high frequencies), or how to add a pad, none of them made these 3 fundamental features easily accessible; some designs allow switches to be mounted inside the mic body, but that requires to physically open the mic everytime to use them, or to salvage a donor body that already had switches inside of it, which cannot be easily had for the super competitive price of the BM-700 / BM-800 / NW-700 / NW-800 chinese mic.
So, I took the best designs I found online (my main source was Homero Leal's Pimped Alice one, you can find it at https://hlpimpedalice.wordpress.com/ ) and decided to implement these three functions using three switches that can sligthly poke out of the donor body; it only requires to drill three holes on the body. I made two boards, one with all the components and a second one that hosts the three slide switches; the main board has 2 slots and soldering pads that end on the edge of the slots, and the slave board has some "fingers" that can be soldered to the pads on the main board. It's like a NES cartridge where there's plated contacts that stick into a connector, only this time there's no connector, you solder them.
You can find a rendering attached to this post.
I just ordered all the parts needed so I can't vouch for the actual functionality of the mic just yet, but I triple checked all the dimensions, the schematic (using Homero's one as well as the original Schoeps CMC5 one), the values of the components (with LTSpice), quality and footprints (the footprint where chosen after the component was picked on Mouser). I made sure to add an insulated standoff for the high impedance point of the JFET, too.
I'll come back on this post whenever I receive everything, I'll assemble three mics (two for me, one for a friend) and will test them all.
Cheers,
Mick
Edit: I would like to thank Homero Leal for giving me some pretty useful information about this design, he was really helpful
I'm new to the group and I would like to contribute something I've been working on and off in the last couple of weeks.
I randomly came across the BM-700/800 cheap chinese SDC mods using the Alice circuit and I really liked the idea as well as the result, getting a microphone worth around 400€ for less than 100€ is no joke; but I didn't like that altough most mods described how to change the high pass frequency (to tame the proximity effect) and some even implemented a low pass (to tame some shrill in the high frequencies), or how to add a pad, none of them made these 3 fundamental features easily accessible; some designs allow switches to be mounted inside the mic body, but that requires to physically open the mic everytime to use them, or to salvage a donor body that already had switches inside of it, which cannot be easily had for the super competitive price of the BM-700 / BM-800 / NW-700 / NW-800 chinese mic.
So, I took the best designs I found online (my main source was Homero Leal's Pimped Alice one, you can find it at https://hlpimpedalice.wordpress.com/ ) and decided to implement these three functions using three switches that can sligthly poke out of the donor body; it only requires to drill three holes on the body. I made two boards, one with all the components and a second one that hosts the three slide switches; the main board has 2 slots and soldering pads that end on the edge of the slots, and the slave board has some "fingers" that can be soldered to the pads on the main board. It's like a NES cartridge where there's plated contacts that stick into a connector, only this time there's no connector, you solder them.
You can find a rendering attached to this post.
I just ordered all the parts needed so I can't vouch for the actual functionality of the mic just yet, but I triple checked all the dimensions, the schematic (using Homero's one as well as the original Schoeps CMC5 one), the values of the components (with LTSpice), quality and footprints (the footprint where chosen after the component was picked on Mouser). I made sure to add an insulated standoff for the high impedance point of the JFET, too.
I'll come back on this post whenever I receive everything, I'll assemble three mics (two for me, one for a friend) and will test them all.
Cheers,
Mick
Edit: I would like to thank Homero Leal for giving me some pretty useful information about this design, he was really helpful