OPEN SOURCE DIY Mic Project - ORS 87 - Stripped Down u87

[micolas]

OK, you helped me a lot, thank you very much

I tested the capsule above, applied more than 65v to it for quite a long time, it worked perfectly, without cutting the sound and did not collapse.

Start a new thread and we'll continue there, along with everyone who has had success with this exciting project.

 

[khalidgul]

So , I am new and read this thread and it made me interested to build it.so i got the Hula cow pcb from pcbways and built it. it worked, but partially, it has low sensitivity and narrow frequency response, i followed the hula cow BOM with the exception I used T-13 transformer, Takstar cts-2 capsule,C-5 33nf and CC-6 156pf, C-7 1uf,cc-9 1uf,fet biased at 8.2 volts and 7.3 volts though same output,pot used is 20kOhm, wiring checked for shortage etc, it seem fine, i have connected capsule front side to signal and bacck plat(blue wire) to pol and the voltage between signal nad pol reads -31v Dc, body from aliexpress.I am sharing the result of the built and seek your guidance to fix the problem.last but not the least I would like to thanks all those who are involved in this open source and are very generous to share their knowledge and making an effort and sparing time to contribute.you are all my heroes.Thank you very much indeed.
test audio is attached.looking forward

 

[Khron]

@Wordsushi - Would there be any interest in etch-at-home ORS87(-Plus) boards?

https://groupdiy.com/threads/feeler...rds-opamp-jfet-u87a-fet847.87606/post-1157363

I just uploaded the copper & silkscreen PDFs to the first post in my feeler thread. Blame @rock soderstrom

 

[johnchantler]

Well......

https://www.pcbway.com/project/shareproject/ORS87_Plus_Open_source_U87_mic_project_2922baaf.html

That being said, BOMs for Mouser and Digikey are still in progress (close to being done), but i'll only get to scrape together a build guide in a few weeks, after i get some blank boards made

went for fedex as its usually cheaper/easier with customs clearance, so my boards arrived here today (ridiculously fast!).

looking good. thanks for doing this @Khron

 

[AdamFrisen]

Are there any sound comparisons made between TSC-2 and Arienne K87 capsule? I didn't find any when I did a search.

 

[Wordsushi]

@Wordsushi - Would there be any interest in etch-at-home ORS87(-Plus) boards?

https://groupdiy.com/threads/feeler...rds-opamp-jfet-u87a-fet847.87606/post-1157363

I just uploaded the copper & silkscreen PDFs to the first post in my feeler thread. Blame @rock soderstrom

Thank you for asking. That's a great question. Though it's far above my ability level to know what to really do with that, there indeed may be interest, but what I'm seeing in the conversations I'm privy to outside of this group are increasing levels of interest from people who are essentially DIY beginners, so buying PCB's is what seems to appeal to them. But if it doesn't involve too many resources to offer an etch-at-home kit with directions, why not? I personally see this project as the gateway between Mic Parts and a Bouchard kit, but also with the possibility to be a foundation upon which to customize and personalize.
A great majority of the people I talk about mics with outside this group are involved somehow, or looking to be involved in voice work and a majority of them are all seeking an affordable u87 alternative, so anything 87 DIY related is probably going to attract some eyeballs. For me, the process of etching a board seems like a next-level way to really DIY it so you've piqued my interest.

 

[Wordsushi]

So , I am new and read this thread and it made me interested to build it.so i got the Hula cow pcb from pcbways and built it. it worked, but partially, it has low sensitivity and narrow frequency response, i followed the hula cow BOM with the exception I used T-13 transformer, Takstar cts-2 capsule,C-5 33nf and CC-6 156pf, C-7 1uf,cc-9 1uf,fet biased at 8.2 volts and 7.3 volts though same output,pot used is 20kOhm, wiring checked for shortage etc, it seem fine, i have connected capsule front side to signal and bacck plat(blue wire) to pol and the voltage between signal nad pol reads -31v Dc, body from aliexpress.I am sharing the result of the built and seek your guidance to fix the problem.last but not the least I would like to thanks all those who are involved in this open source and are very generous to share their knowledge and making an effort and sparing time to contribute.you are all my heroes.Thank you very much indeed.
test audio is attached.looking forward
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That's actually @homero.leal's board. Maybe someone can put some eyeballs on this.

 

[Khron]

But if it doesn't involve too many resources to offer an etch-at-home kit with directions, why not?

Well, offering a full etch-it-yourself is a bit outside my scope, actually. "Back in the day" (say, 10-15 years ago), that's all we DIY'ers had Before all these "$5 for 5-10 PCB" deals were a thing...

Anyway, even kitting up parts is one step further than i'm willing to go, but as mentioned earlier, Digikey & Mouser BOMs are almost done (just gotta triple-check everything, for my own peace-of-mind), and i'll try to scrape together some build guide as soon as i have some blank boards in hand Probably unwise to hope for the guide earlier than next month, though