Beginner advise to build an LDC

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Duizels

Well-known member
Joined
May 1, 2016
Messages
55
Hello,

Since about a year I've been getting more interested in building my own microphones. I had a friend help me make on of the microphone-parts kits and it was fun to do and the sound amazed me for sure. He initially volunteered to help me make more (custom stuff) but he eventually got too busy with family life and now I'm stuck with a box full of parts and no technical/electronics experienced person to help me.

I've never been into electronics before, I would even say I expect it will be pretty difficult for me to learn (the math/logical part of it) because I am more of a creative person (I paint and design for a living) and I am really bad at analytical. I never been able to pass a math exam even with hours of extra tutoring haha. However, I do notice I keep getting excited about reading about capacitors, diodes, op amps and what not, even if most of it is over my head, I just love the idea of being able to put something together with your own chosen parts and see how that sounds.

So now I am wondering. I have 2 capsules lying around, several donor bodies, a soldering iron, a box full of general components, and the desire to build a working mic. Would it be possible, with your advise to make something? I looked into beginner electronic kits to gain experience, but I just don't have a use for a guitar pedal or stomp-box, so they really didn't motivate me to start at all. The prospect of making my own mics however, would motivate me to no end...

I think for a long time, knowing my struggle with understanding math, physics etc I will be stuck in the phase of "just doing what Im being told to do" in order to get something that works,  without actually understanding myself the reasons for it (sort of the 'paint by numbers" kit approach) although I love learning and reading up on the subject. Hard to know what to expect, some of the stuff sounds incredibly complicated to me. But I also would love to experiment with different transformers, capacitors, etc to hear what a difference it makes to my mic sound. That has quite a big appeal to me.

Knowing an LDC requires the pcb/components to be grounded into the body, I might need to start with a ready-to-use pcb from a kit ? Or are there other ways to get started?  Is there a relative simple schematic I would be able to follow and assemble something with my parts?  Love to hear your thoughts / reccommendations.

Thank you, and I apologize if in my newbness Ive asked many dumb questions :)

Cheers!!

Chris

 
Best way is to start with something really simple like a DI or a Reamp kit.  DIYrecording has a few very basic kits that aren't expensive,  if you find you have trouble getting these together then you will know not to spend alot of money trying to put together an expensive microphone.  If you have no trouble with the simple kits, then you could move on to a cheap diy mic from Aurycle.com .  A little harder as the instructions aren't the best so it will make you read the schematic and figure things out.  If you handle those then you will have the confidence to spend some money on say a nicer mic from microphoneparts.com or even put together one of the mics from Poctop or the well documented C12 from Matador and Chunger.    As well as spending all your free time reading and rereading the forums :)
 
Don't really want to discourage you from building a mic, but I've built and worked on several comps, mic preamps, EQ's and mics. Mics are the hardest to assemble. Lots of delicate bits like capsules and small components and connectors. And the high impedance circuits surrounding mics can be troublesome. Especially if you have no experience soldering.  The suggestion to start with a DI box or pedal is good advice.
 
Another great entry point would be some of the high quality preamp kits - by Seventh Circle Audio, SoundSkulptor, and I believe Hairball Audio has one too. These are amazing sounding, [relatively] inexpensive, and should last a lifetime too.
 
Thanks for the tips, I totally get the advise of learning to solder on simple projects. I've already looked numerous times in to DIRE and FiveFish, Seventh Circle kits. They look great for sure. But as it stands I already have very good mic preamp of $2.000 so I was not really keen on investing in a lunchbox/500 rack and modules. It added up to quite a bit of money, and doesn't move me in the direction I want to go: Microphones. That's why I stated what simpler microphones I might be able to start with, instead of totally un-related kits just for the sakes of learning to solder.

I will have a look and see what I'm going to do. I understand your feedback and you are probably right, I just don't like it :) Hehe.

 
If you really have to start with a mic, then build one of the cheap aurycle mics and even if it doesn't work your not out much money and you still have a decent Mic body.
 
Carnesd said:
If you really have to start with a mic, then build one of the cheap aurycle mics and even if it doesn't work your not out much money and you still have a decent Mic body.

Ok yep, those looked quite affordable and fun to build.  I'm also practicing some soldering on cheap chines mic pcbs and old parts I have lying around. Just to get a feel for it.

 
Ordered a dozen of cheap practice kits from ebay to get some experience. Total of 7 dollars so Im not breaking bank if anything fails :) and who doesnt want a doorbell or flashing led ;)

 
Another good cheap project is a cheap oscilloscope kit or signal generator from ebay.    You can use them to get familiar with using a scope and generator for when you need to bias your fet  mics or for troubleshooting.
 
Carnesd said:
Another good cheap project is a cheap oscilloscope kit or signal generator from ebay.    You can use them to get familiar with using a scope and generator for when you need to bias your fet  mics or for troubleshooting.

Ok nice, yep ordered :)
 
Ok while I wait for my beginner practice kits to arrive, I wanted to post the mic me and my friend were trying to build, but he quit so left me with the parts, and currently it does not fire up.

What he tried to make was a copy of a microphone-parts kit I have, but use connectors so we could easily change out caps, transformer and capsules to test what they would sound like, without having to desolder them every time. I think in his schematic he left out the Pad and Omni switch that was normally included in the mp schematic, but Its hard for me to "read" and compare the layouts, cause Im not experienced with it. I have not troubleshooted yet either myself, cause I don't know how to use the multimeter yet, and don't want to break anything :)

Maybe some of you have some pointers for me? I would love to be able to get this thing working, just for the fun of it !
The only thing I noticed is that at the back, some soldering connections "bridge/run into eachother", not sure if that's intentional or even matters. The other is that I am not sure where each connector was meant to go, for example where to place the big capacitor. Im fairly sure the capsule is connected to the two pins at the edge of the board. The other loose wire is one coming out of the transformer.

CircuitTotal2.jpg


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CircuitBack2.jpg


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CapsulesConnectors.jpg


Chris
 
I notice the photos i posted show up nicely when viewed on a computer, but too large on mobile making it hard to view. I apologize, anyone know how to fix this?

 
Duizels said:
... I wanted to post the mic me and my friend were trying to build, but he quit so left me with the parts, and currently it does not fire up.

Is the FET correctly biased? Because there is a lot of tolerance in FET production, you have to adjust the value of the source resistor for a specific FET.
Also I don't think it is a good idea to connect the (high impedance!) gate connection on a piece of perfboard.
This may cause leak currents and add extra noise. It would be better to have the gate connection 'floating' in the air, or use a teflon feedthrough.
 
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