How can I learn to make my own preamp circuit?

[Jark]

Hello,

I am very new to this space, and currently, I am trying to build my own DIY microphone. Currently, I have little to no "real" experience in electrical engineering, as the most I have learned about is basic resistor, capacitor, inductor circuits from college physics. I could just buy some preamp circuit on the internet, but I want to be able to actually understand the mechanics of what is going on inside of a preamp circuit, and maybe build a prototype on a breadboard or something. However, when I look at a schematic, I am just confused and have no idea where to look at. Can someone point me to some resources which can help me get a better understanding of electrical engineering and preamp circuits overall?

Thanks

 

[a soBer Newt]

I would recommend Steve Dove Console Design, and Small Signal Audio Design.

 

[ruffrecords]

There is a meta thread containing loads of recommended books.

Cheers

Ian

 

[ccaudle]

It sounds from your comment about getting confused that a basic overview of how to interpret schematic symbols and the historical conventions around drawing schematics would be useful.
When I was getting started there were introductory books for electronic technicians which were helpful for acquiring that kind of foundational knowledge, but I am not sure what the current equivalent of those would be. Much of the knowledge and techniques taught then for technicians started with basic transistor circuits, which are still very much useful for microphones and classic audio circuits, but much less useful for modern computers and consumer electronics, so I don't know if current generation textbooks for technicians would still cover the basics in the same way or not.

 

[Brian Roth]

It's been awhile since I looked through one of his books (they used to sell them at Radio Shack) but IIRC Forrest Mims books were pretty decent for beginners.

https://www.amazon.com/s?k=forrest+mims&ref=nb_sb_noss

Bri

 

[Jark]

Thanks for the replies everyone! I will look into these books.

 

[13engrsapper]

Here is an easy tube build, very low component count - https://www.tangible-technology.com/tubes/1566/1566.html

 

[13engrsapper]

I would recommend Steve Dove Console Design, and Small Signal Audio Design.

Good texts, but hose are kind of deep reads to start out, IMHO.

 

[ccaudle]

This is a later revision of one of my first electronics textbooks, it is inexpensive and might be worth checking out:
https://www.abebooks.com/servlet/Bo...lvino&sortby=17&cm_sp=snippet-_-srp1-_-title1

 

[Khron]

Rod Elliott's articles might be worth looking into, as well..? I'm linking the "Beginner's luck" section directly, below:

https://sound-au.com/articles/index.htm#begl

 

[MidnightArrakis]

Then, of course.....should you wish to take your newly-designed circuit beyond being just a breadboard prototype circuit and you would like to have it become a "real thing" that you can put inside some manner of a microphone housing.....you will also need to learn how to properly design and layout a PCB as well. And.....closely following the learning of that specific skill, you will also need to already have and/or learn at least a modicum of mechanical design expertise so you will be able to build your microphone and put it all together. YAY!!!

BUT, WAIT!!! -- THERE'S MORE!!! ---- Even if you only stay at the breadboarding design-level of your new endeavor, you will also need to learn and/or pickup on how to specify, source and purchase all of your electronic components for your new designs. As an example, like you I am here in the U.S., but for a little project that I am currently working on, some of the capacitor values and types that I need for a circuit were only readily available from a distributor that is located in Greece!!! They will be here around mid-March.

So.....just prepare yourself for a "long road ahead" of continual learning while enjoying the satisfaction of your circuits as you power them up!!! Are we having fun yet???

/

 

[JohnRoberts]

Complex schematics can be a little intimidating to inexperienced readers. It helps to break down the schematic into smaller subsections with only a handful of components working together. You also need to understand how passive components and active devices work. Most large complex schematics contain multiple simple subsections.

It might be useful to learn how one transistor circuits work, and simple op amp circuits. Divide and conquer.

JR

 

[k brown]

Hello,

I am very new to this space, and currently, I am trying to build my own DIY microphone. Currently, I have little to no "real" experience in electrical engineering, as the most I have learned about is basic resistor, capacitor, inductor circuits from college physics. I could just buy some preamp circuit on the internet, but I want to be able to actually understand the mechanics of what is going on inside of a preamp circuit, and maybe build a prototype on a breadboard or something. However, when I look at a schematic, I am just confused and have no idea where to look at. Can someone point me to some resources which can help me get a better understanding of electrical engineering and preamp circuits overall?

Thanks

By 'preamp' do you mean the internal circuitry of a DIY mic, or an actual microphone preamplifier that a mic plugs into?

I always thought it was a confusing habit to call mic circuits 'preamps', when they are really impedance converters and balanced cable drivers.

 

[JohnRoberts]

By 'preamp' do you mean the internal circuitry of a DIY mic, or an actual microphone preamplifier that a mic plugs into?

I always thought it was a confusing habit to call mic circuits 'preamps', when they are really impedance converters and balanced cable drivers.

They actually "amplify" the tiny voltages coming from microphones, and are often "pre" the line level portion of mixers/consoles.

Of course you are entitled to call them whatever you want.

JR

 

[k brown]

They actually "amplify" the tiny voltages coming from microphones, and are often "pre" the line level portion of mixers/consoles.

Of course you are entitled to call them whatever you want.

JR

Maybe I wasn't clear; of course the mic inputs of mixers and interfaces are rightly called preamps; I just think it clouds clear communication to call the internal circuitry of a microphone, also a 'preamp'; technically it is, but calling both a mic's internal electronics and the mic inputs of a mixer/interface (or external microphone amplifier) "preamps" needlessly invites confusion.

Indeed, we still don't know which the OP was asking about; it seemed to me it was internal microphone electronics, since the first sentence referred to a DIY microphone.

 

[velo]

Hello,

I am very new to this space, and currently, I am trying to build my own DIY microphone. Currently, I have little to no "real" experience in electrical engineering, as the most I have learned about is basic resistor, capacitor, inductor circuits from college physics. I could just buy some preamp circuit on the internet, but I want to be able to actually understand the mechanics of what is going on inside of a preamp circuit, and maybe build a prototype on a breadboard or something. However, when I look at a schematic, I am just confused and have no idea where to look at. Can someone point me to some resources which can help me get a better understanding of electrical engineering and preamp circuits overall?

Thanks

You may want to find a good introductory book on RC circuits in which you learn Ohm's Law and build up from super simple circuits. I highly recommend getting an experimenter's kit with a breadboard and a bag of resistors, transistors, LEDs, capacitors, and such. Get a digital multimeter and have fun learning the basics. Everything else will make much more sense after that.

There's a bit of a gap between analog and digital circuit design. My career took me down the digital path so now 30 years later it feels like I am learning something new but my solid understanding of the basics helped tremendously.

If you're into the theory then perhaps a book on electrical engineering design or one of these books: https://bookauthority.org/books/best-electrical-engineering-books

I have an earlier edition of the Art of Electronics and my other goto book isn't listed there but there are some interesting titles for beginners at the above URL.

I built five D.I.Y. mics and restored some old gear. I'm tackling the restoration of a mixing console now that I hope to mod with discrete op-amps.

Good luck!

 

[jokeramik]

recommend:
1. Walt Jung - IC OP Amp Cookbook all edition also for audio available

2. H. Römisch - Berechnung von Verstärkerschaltungen

3. Durney and Johnson - introduction in modern electromagnetics

4. Telefunken Fachbuch - Der Transistor

5. Feldtkeller/Bosse - Einführung in die Nachrichtentechnik

6. Küpfmüller - Einführung in die theoretische Elektrotechnik

7. Foecke: Introduction to Electrical Engineering Science

8. Tobey - Graeme - Huelsmann: Operational Amplifiers

9. Motchenbacher - Low-Nois Electronisc System Design

and much more....you can never know enough....

 

[freshtapescent]

Hey Jark,
Your best bet is going to be to buy and build a DIY kit to start. I believe Micparts.com and others have decent microphone kits. Without much knowledge or experience, dipping your toe into design is gonna be overwhelming and you’re not likely to end up with something usable and robust. Maybe that’s ok. The issue is that audio in general and microphone ’head amps’ especially have a very hard job…amplifying minuscule capsule-level signals cleanly and quietly is very difficult.

Put together a DIY kit, troubleshoot it for a few days because it doesn’t work, retrace the build step by step, study the heck out of it, get it to work, figure out how it works, then use it for a while. In a few months, try tweaking some values to see what that does for sonics. Change values on some coupling caps, etc. At least you’ll know that it’ll do the thing you want it to if you follow the instructions. DIY design with no experience is a bit like the average Joe trying to land a commercial aircraft. Not that it couldn’t be done, but the 40% of respondents who claimed they could ‘most likely land the plane’ couldn’t find the ‘autopilot’ button.

Hello,

I am very new to this space, and currently, I am trying to build my own DIY microphone. Currently, I have little to no "real" experience in electrical engineering, as the most I have learned about is basic resistor, capacitor, inductor circuits from college physics. I could just buy some preamp circuit on the internet, but I want to be able to actually understand the mechanics of what is going on inside of a preamp circuit, and maybe build a prototype on a breadboard or something. However, when I look at a schematic, I am just confused and have no idea where to look at. Can someone point me to some resources which can help me get a better understanding of electrical engineering and preamp circuits overall?

Thanks

 

[Ted Krotkiewski]

I would recommend Steve Dove Console Design, and Small Signal Audio Design.

WOW! The Steve Dove Console Deisgn!! I had no idea that book existed. It contains so much great info! Thank you so much for that one!

 

[JohnRoberts]

It's nice to see all these shared study resources but we do have a meta resource sticky at the top of this forum https://groupdiy.com/threads/meta-meta-look-here-for-overview.16013/ and another sticky full of resource books on top of the drawing board. https://groupdiy.com/threads/analog-theory-design-reference-books.77804/

In fact this sub forum is about trouble shooting and repairs so I need to move this design query over to the Drawing board sub forum.

JR