micropohne capsul how much VDC?

[mic test]

So can I do this without unsoldering the capsule? I have now removed c 3 again

 

[micolas]

So can I do this without unsoldering the capsule? I have now removed c 3 again

Yes it is possible. Then you need to measure at the connection point between diode D1 and resistor R2

 

[micolas]

Here Upol is measured against GND

 

[micolas]

Here Upol is measured against GND

If you measure on the capsule, it indicates a much lower voltage due to the relatively small internal resistance of DMM, of about 2Mohm for example

 

[mic test]

Upol-GND=52,2V DC
Is this still within the permissible tolerance range?

 

[micolas]

Upol-GND=52,2V DC
Is this still within the permissible tolerance range?

Did you measure where POL is written on the PCB?

 

[mic test]

r2 and gnd

 

[mic test]

should I measure gnd at the bottom of the board and pole at the top of the board?

 

[micolas]

should I measure gnd at the bottom of the board and pole at the top of the board?

Measure at all points in the image, including POL.
Does it indicate at any point a voltage greater than 52,2 v?

 

[mic test]

d1 and gnd its 55,5v

 

[mic test]

Or do you mean I should measure from pole to r1 and r2 to poll

 

[micolas]

Or do you mean I should measure from pole to r1 and r2 to poll

No.

That's ok, the OPA-Board supplies less than 12v to the DC/DC converter therefore it delivers less than 60v. But it's OK.In the original SC600 circuit, the capsule works at 46v.
At the POL point, how much does it measure?

 

[mic test]

gnd and measured with an angle-closed diaphragm 18,1V DC at pol

 

[micolas]

gnd and measured with an angle-closed diaphragm 18,1V DC at pol

Because of the impedance of the DMM, the measurement at POL or Capsule is not real.

Under current conditions, if everything is connected correctly the microphone should work fine. With lower Upol, headroom is larger, supports higher SPL and has lower distortion.
If we want to increase the bias voltage, we will do it later.

 

[mic test]

OK, then I'm not going to try to get rid of the humming noise with the aluminum foil. I'm really excited to see whether something will change
Thank you very much for so much help

 

[micolas]

OK, then I'm not going to try to get rid of the humming noise with the aluminum foil. I'm really excited to see whether something will change
Thank you very much for so much help

I am waiting for good news!

 

[mic test]

Thank you very much it still goes have a minimal noise of its own can be that it is from the fetch housing which material will be the best for a housing copper aluminum brass or steel ?

 

[micolas]

Thank you very much it still goes have a minimal noise of its own can be that it is from the fetch housing which material will be the best for a housing copper aluminum brass or steel ?

The capsule is not adequately shielded, it needs a finer grille (also connected to GND)
It must be fully shielded in the XLR connector area as well
*
The most important question is:
Does the microphone work?
*
The capsule is ok, is the diaphragm still sucked by the backplate?
Have you tested both sides of the capsule?
Apart from the hum due to imperfect shielding, does the mic have any noticeable self-noise? (the solution of connecting the opamp input , the diaphragm wire, with direct physical contact with the PCB surface is not recommended for high impedance)
Can you post more interior pictures and a sound sample?

 

[micolas]

You measured the polarization according to the picture
Even if you don't shunt D1, about
55.5v will reach the capsule(to put it simply, the polarization circuit of the capsule has a kind of "electro-static" behavior, without current consumption)
so it's ok.

 

[mic test]

Hello, good day, I'm still at work and will make a sound recording and a picture with a measuring device as soon as I get home