[Solved] Weryfikacja i optymalizacja schematu mikrofonu zasilanego z baterii 9V – PDF

Dzień dobry,
poszukuję doświadczonego elektronika, który mógłby sprawdzić i zoptymalizować schemat połączenia mikrofonu. Projekt dotyczy prostego układu zasilanego z baterii 9V, stosowanego w urządzeniu audio.

Posiadam plik PDF ze schematem oraz dane techniczne mikrofonu.
Potrzebuję pomocy w zakresie:

weryfikacji poprawności układu,

ewentualnej optymalizacji (szumy, pasmo, impedancje),

przygotowania poprawionej wersji schematu.

Preferowany kontakt mailowy lub przez forum.
Z góry dziękuję za pomoc!

And where is this scheme?

Microphone data (e.g. sensitivity characteristics) could also be useful.

Fellow Author with little interest in the subject...

Dodano po 1 [minuty]:

I apologize for missing your posts. I've attached the schematic above.

Dodano po 38 [sekundy]:

I apologize for missing your posts. I've attached the schematic above.

Resistors R1-R5 - this is where the electret microphones are powered. Have you specified the type of microphone?

Hello,
elaborate, what is the circuit to be, on what components and what is the application?
So far I can see that you have some microphone cartridges, presumably with their own preamp, fed from 9 volts, further this is all summed up and fed to the gain with an operational amplifier, which I guess is supposed to "do" the compressor, because this is how it has a corrected feedback loop. You're using a relatively good operational amplifier, but it's not clear what the microphones are.
It's hard to judge how the whole thing will perform without knowing the details.
Regards

yogi009 wrote:

Resistors R1-R5 - this is where the electret microphones are powered. Have you specified the type of microphone?

The type of microphone I use is the Primo EM301. Yes, the power is supplied through resistors 1-5

Dodano po 37 [minuty]:

>>21576403
Hello,

Thank you for your message.
You are correct - I currently have a circuit that uses electret condenser microphones. These are highly sensitive, three-wire capsules with built-in FET preamplifiers. They are powered by a 9-volt battery (PP3) through a simple resistive bias network. Each capsule is decoupled using capacitors and mixed passively.
The mixed signal is then fed to an op-amp stage based on an OPA2134 operational amplifier. The op-amp stage also includes a feedback loop intended to act as a soft compressor, although in practice this part of the design works unreliably - most likely due to incorrect component values or topology.
My main goals are:
Power from a 9-volt battery;
Maintain low-noise performance.
The current circuit does not work as expected. I am looking for someone who can revise or redesign it properly.

Hello,
describe exactly what is not working as expected.
What does this "noise" consist of? Are we talking about network noise? This is more likely to be due to installation errors or lack of shielding.
Regards

I'd have a look at the topology, especially pay attention to the real and virtual ground. I think an audio generator (any, could be a simple 1kHz) and an oscilloscope should tell you the reason for the trouble. I'm assuming that with this quality of content in your project description, you are able to do the correct shielding of the module and wiring. Write more about the length of the wires connecting the microphone module to the preamp module.

gafregafre wrote:

.
I have a PDF file with the schematic and technical data of the microphone.

The file will not do anything.
You need to work on a prototype.

gafregafre wrote:

I need help with: possible optimisation (noise, bandwidth, impedances)

No expected figures.

I found the person on this site who solved my problem. Thank you all.