create a new circuit which way is there and what is needed to create a microphone circuit

[mic test]

How is a microphone circuit built? How do you get started? Are there any ideas for creating a good low-noise drawing? I would like to learn how to do it. You can find very little on the internet. How is it calculated and what values do you have to arrive at? The best thing for the capsule would be a very simple circuit to understand it

 

[Khron]

Why reinvent the wheel?

https://www.audioimprov.com/AudioImprov/Mics/Entries/2015/4/23_Basic_FET_Microphone_Circuits.html
https://www.audioimprov.com/AudioImprov/Mics/Entries/2014/2/7_Mic_Electronic_Eq_Pt.1.html
https://www.audioimprov.com/AudioImprov/Mics/Entries/2014/2/7_EQ_Pt.2_-_Transformerless_Mics.html
https://www.opic.jp137.com

You can find very little on the internet.

... Especially if you don't look for anything... Or if you don't use the right search terms... And/or if you expect everything to be presented to you on a silver platter...

PS. Shameless plug...

 

[KrIVIUM2323]

Why not go back to beginnings..? A tube circuit impedance converter? Like a condenser capsule plugged right into a cathode follower stage?
Something like a C12a or a Sony c37/C800 ( non G)?
I think i've seen those circuits's schematics around... Maybe in the Technical Documents subforum... under Sony or Akg folder.

Khron, don't be rude, we all faced the issue when we didn't knew how to recognize a circuit or it's 'nickname'.

 

[rock soderstrom]

Why reinvent the wheel?

How is a microphone circuit built? How do you get started? Are there any ideas for creating a good low-noise drawing? I would like to learn how to do it. You can find very little on the internet. How is it calculated and what values do you have to arrive at? The best thing for the capsule would be a very simple circuit to understand it

In general, the requirements are quite simple, the devil is in the detail. You essentially need an impedance converter that converts the signal from the extremely high impedance of the microphone capsule to a low value of around 200 ohms. I would start with the simple circuits mentioned above and good electret capsules and then develop further and further. Study the posted links and classic circuits. If you have specific problems, you can ask for help here. Good luck and have fun!

 

[KrIVIUM2323]

Let's start with a tube classic article:
https://tapeop.com/tutorials/34/david-royer/

https://tapeop.com/tutorials/25/dave-royer/

And last but not least:

https://www.gyraf.dk/gy_pd/g7/gic.htm

Once you got them, time to go FET.

 

[mic test]

OK, thank you very much to everyone. I will continue to learn. I would like to make a circuit myself, not just buy it and solder it. I think once you do the math yourself, it will be much easier to understand how the circuit can be expanded or how different transformers can be used. I will try the mxl circuit solder and see if I can change anything

 

[k brown]

For safety's sake, I wouldn't suggest a complete beginner start with anything involving tubes, and their attendant high voltages.

FET circuits are much simpler and safer. Even simpler if using an electet capsule, and there are many quality choices out there these days.

 

[k brown]

Let's start with a tube classic article:
https://tapeop.com/tutorials/34/david-royer/

https://tapeop.com/tutorials/25/dave-royer/

And last but not least:

https://www.gyraf.dk/gy_pd/g7/gic.htm

Once you got them, time to go FET.

There's no schem in that second link.

 

[KrIVIUM2323]

(OK, thank you very much to everyone. I will continue to learn. I would like to make a circuit myself, not just buy it and solder it. I think once you do the math yourself, it will be much easier to understand how the circuit can be expanded or how different transformers can be used. I will try the mxl circuit solder and see if I can change anything

But to be able to design something you have to understand how it works and design goal first.
The links i gave are just that, a non nonsense explanation of circuits using the most basic kind of circuits with the most basic electronic components ( triode or triode wired pentode), by someone which earn his life designing such things ( Royer like in Royer Labs). Same can be said about G7 and Jakob ( Gyraf).

In my view if you understand the principle in there and you make a bit of research about what is a cathode follower and a grounded cathode amplifier and how you do the math with them then you would have made a large step toward designing a circuit. But there is nuances and details in mic circuits that requires a bit more than only basic theory: high impedance components and tubes lead to somewhat 'fringe' design in some parts of circuits.

It took me 5 to 6 years study to really get what is at play and be able to design something from scratch. That said i'm not the brightest mind on earth despite i understand fast if you explain looonnng enough! Lol.



There is no schem in the u47 article? Yes, such a shame. Or not...
Maybe it was an ambush to push mic test to search by himself, but if it's really asked by popular request here is where to find it ( and the thread is an interesting read about some reality of mics in general imho):

https://groupdiy.com/threads/barstow-u-47-mod-of-marshall-mxl2001.63637/

To be blunt like Khron, i don't like to spoonfeed people. There is many search engine and we have a full section dedicated to technical documents...

I think you have an expression in english about giving a man a fish and teaching someone how to do it by himself...

And it's one of the many lessons i learned in here: make your homeworks (search) before asking anything.

Playing with electicity can be lethal.
Sure, start to be circa 20v dc and 20ma iirc. So yes be careful if you plan to build anything not powered by AA battery... so almost anything involving mains is potentially lethal. Even a DMM can be if you decide to try to measure the internal resistance of your body, there was an Darwin Award about it ( US Army have a very serious warning note about it as some smart ass probably tryied to do it and succeeded to kill himself)!

Mic test asked for explanation of how to design. I suggest going back to the roots to understand the way followed to arrive at state of design as it is now. Read what i wrote previously, 'once you get it (i meant understand) it's time to go FET' i think i stated. I didn't suggested to build anything.

If you decide you do, then it's at your own risk and you should take care about yourself and use safety rules.

if you don't know what they are and where to find advice, ask for it, or do under supervision of someone which know them.

 

[Accelerator]

@mic test​

I attach for you some schematics of some legendary tube microphones and the Mods on them by Oliver Archut (R.I.P.)…

Take as much time as you like to have a peep show with them, after all your woman will not feel jealously if you are looking at these tube microphone schematics…

 

[k brown]

OP: pleas read post #7 again . . .

 

[mic test]

hello Is it possible to operate a Rohen microphone without an extra power supply, just with the 48 volt phantom power, i.e. without 230 volts? Why are these power supplies there?

 

[pasarski]

hello Is it possible to operate a Rohen microphone without an extra power supply, just with the 48 volt phantom power, i.e. without 230 volts? Why are these power supplies there?

https://support.mxlmics.com/support...ower-supply-vs-phantom-power-which-do-i-need-

 

[mic test]

I found this, it's a tube mic with a 3 pin XLR
https://www.alibaba.com/product-det...ml?spm=a2700.shop_plgr.41413.5.34a77121QxWpW9

 

[mic test]

https://www.pcbway.com/project/shar...age_Multiplier_for_Condenser_Microphones.html
Is it possible to add a tube to the circuit?

 

[KrIVIUM2323]

hello Is it possible to operate a Rohen microphone without an extra power supply, just with the 48 volt phantom power, i.e. without 230 volts? Why are these power supplies there?

Which supply? Phantom or the one into a tube mic?

 

[pasarski]

I found this, it's a tube mic with a 3 pin XLR
https://www.alibaba.com/product-det...ml?spm=a2700.shop_plgr.41413.5.34a77121QxWpW9

Wow, you can find weird things at alibaba I really don't know what that tube looking device is. Can someone please enlighten us? If you scroll down you see very different circuits. Alibaba is like a box of chocolates..

That said, there are some old hearing aid tubes that could work with phantom power. You can find info here if you do a search. But I really suggest to first learn at least the basics about microphones before starting to design microphones, not to mention really weird ones. I'm like you, always wanting to dive straight to the deep end. But I've learned it doesn't lead to great results

 

[KrIVIUM2323]

Yes. Have you read and digest the articles linked? The one from Khron and mine?

 

[Khron]

I found this, it's a tube mic with a 3 pin XLR
https://www.alibaba.com/product-det...ml?spm=a2700.shop_plgr.41413.5.34a77121QxWpW9

Yes, because as everyone knows, stuff you find on AliExpress/AliBaba is always 10000000% genuine and never fake or low quality...

Or as a more general rule, not everything you read on the internet is true / accurate

But to echo the thoughts of others, first decide WHAT you want to put together, WHY you want that particular choice, and WHETHER you have the skills / qualifications to achieve that.

I hate to sound like I'm "gatekeeping" or anything, but biting off more than you can chew, and risk hurting yourself (or worse, and/or even others) is definitely NOT what you want, and even more definitely, not what any of us here would want to even risk advising, not to mention enabling.

 

[mic test]

Yes, I've read it and have already started with the MXL on a perforated board. I bought a big box from Mauser. I'll have to see if I have everything. If not, I still have a defective keyboard. There's a lot in there too haha