micropohne capsul how much VDC?

[mic test]

This is a HEX CMOS inverter based voltage multiplier. It is used for condenser microphone biasing. It takes 12VDC in and turns it into up to 80VDC. For 60VDC, omit the last capacitor C3. The Hex Inverter needs to run off off 12 Volts or above. And it needs to be a schmitt trigger type. The schematic has a MC33761 shown in it, that is not required and can be bypassed. Also the trim pot is jumpered as well. You can use these if needed for other voltages. I did not. Here is the build video for microphones
https://www.pcbway.com/project/shareproject/Dual_OPA__Alice__Microphone_Circuit.html
https://www.pcbway.com/project/shar...age_Multiplier_for_Condenser_Microphones.html
https://www.thomann.de/de/the_tbone_mikrofonkapsel_sc600.htm
after I unplug the mic again the membrane is crumpled for 15 minutes then the membrane is like new again? is it too much vdc? and with a lot of vdc I should only run a capsule like that

 

[micolas]

This is a HEX CMOS inverter based voltage multiplier. It is used for condenser microphone biasing. It takes 12VDC in and turns it into up to 80VDC. For 60VDC, omit the last capacitor C3. The Hex Inverter needs to run off off 12 Volts or above. And it needs to be a schmitt trigger type. The schematic has a MC33761 shown in it, that is not required and can be bypassed. Also the trim pot is jumpered as well. You can use these if needed for other voltages. I did not. Here is the build video for microphones
https://www.pcbway.com/project/shareproject/Dual_OPA__Alice__Microphone_Circuit.html
https://www.pcbway.com/project/shar...age_Multiplier_for_Condenser_Microphones.html
https://www.thomann.de/de/the_tbone_mikrofonkapsel_sc600.htm
after I unplug the mic again the membrane is crumpled for 15 minutes then the membrane is like new again? is it too much vdc? and with a lot of vdc I should only run a capsule like that

If the diaphragm is sucked in again when powering the circuit, take some pics of the capsule and post them here.
Depending on the aspect, we can have some useful information

 

[micolas]

@mic test

In the tests you used only the front diaphragm FD of the capsule and left the rear diaphragm RD unconnected?
You can try to repeat the test by connecting only the rear diaphragm now, to see if it also collapses or not.
Perhaps the front diaphragm was insufficiently tensioned (stretched) from the factory.

You can also wrap the 3D printed plastic body in aluminum foil several times, fix it and connect it to GND, it reduces the hum, so you can continue working.

 

[mic test]

I'll do it, I'll just get some aluminum foil from the kitchen. Pictures will follow, thanks for the help

 

[micolas]

I'll do it, I'll just get some aluminum foil from the kitchen. Pictures will follow, thanks for the help

Excellent!
That's the true DIY spirit!

 

[mic test]

12VDC in and turns it into up to 80VDC. For 60VDC, omit the last capacitor C3. The Hex Inverter should I take c3 away first?

 

[micolas]

12VDC in and turns it into up to 80VDC. For 60VDC, omit the last capacitor C3. The Hex Inverter should I take c3 away first?

Post the schematics here
-circuit
-dc/dc converter
Let's discuss exactly on the diagram, with the names of the components, voltages at different points, etc.

 

[micolas]

You know, you can upload the pdf here and it can be viewed at maximum quality

 

[mic test]

I have this circuit board and these are the components

Part​	Designator​	Mouser P/N​
OPA1642​	IC1​	595-OPA1642AID​
2.2K 1/4W 1%​	R3, R4, R6, R7​	MFS1/4DCT52R2201F​
47 1/4W 1%​	R1, R2​	MFS1/4DCT52R47R0F​
200 1/4W 1%​	R5​	MFS1/4DCT52R2000F​
47K 1/4W 1%​	R8, R10​	MF1/4DC4702F​
1Gig 1/4W​	R11​	279-RGP0207CHK1G0​
12V Zener​	D3​	78-TZX12D​
47uF 63V​	C2,C3,C4, C5, C6,​	667-EEU-EB1J470SJ​
.1uF 50V​	C1, C7​	594-K104K15X7RF53H5​
22nf**​	External​	594-K223K15X7RF5UL2​

 

[mic test]

This is the amplifier board

Hex Inverter​	757-TC4584BFELNF​	1​	IC-1​
Diode​	512-1N4148​	8​	D1, D2, D3, D4 ,D5, D6, D7, D8​
.01uF Cap​	594-K103K15X7RH53L2​	6​	C3, C4, C5, C6, C7, C8​
.1uF Cap​	K104M20X7RH53L2​	2​	C1, C2​
4.7uF cap​	667-ECE-A1VKS4R7​	1​	C10​
1nF Cap​	594-K102J20C0GH5TH5​	1​	C9​
10K 1% resistor​	660-MFS1/4DCT52A1002​	1​	R3​
1M 1% resistor​	660-MF1/4DCT52A1004F​	2​	R1, R2​

 

[micolas]

OK,
we have the documentation here

 

[micolas]

Let's lower the capsule's polarization voltage a bit
We remove C3 and thus disconnect IC1C.

 

[mic test]

I think the capsule gets 80vdc? Isn't that too much for a 1.2 inch capsule? Should I first take c3 from the hex inverter then I still have 60 VDC if I understand that correctly

 

[micolas]

To desolder C3=10nF we touch both ends of the capacitor simultaneously. Thus, it is easily removed and the PCB is not destroyed either.

 

[mic test]

Everything's fine, I'll just do it and see if it's any better

 

[micolas]

I think the capsule gets 80vdc? Isn't that too much for a 1.2 inch capsule? Should I first take c3 from the hex inverter then I still have 60 VDC if I understand that correctly

Yes, we reduce Upol to 60v

 

[micolas]

Everything's fine, I'll just do it and see if it's any better

Then you measure the voltage at the dc/dc converter output

 

[micolas]

It is measured in the point
POL_T

 

[mic test]

How should I measure the audio interface 48v and dal poll on the Hex Inverter plate and signal on the opto board?
Do I have to solder the membrane cable from the board first or can I also measure it that way?

 

[micolas]

How should I measure the audio interface 48v and dal poll on the Hex Inverter plate and signal on the opto board?
Do I have to solder the membrane cable from the board first or can I also measure it that way?

You don't need to connect the diaphragm of the capsule, just feed the microphone from the audio interface.