Hi there, new to the forum and was trying to build the mic but got stuck at the 2200 if caps, I’ve attached pics showing cap 3 and 4 with the polarity’s not matching the schematic! Am I reading this wrong or are they wrong on the perf board ?
I finally got around to getting my mic setup to where i can test it and im having a couple issues, ive had it mostly done for about a month.
1. I dont quite see how im supposed to have the 3 wires going out of the audio interface that goes into the 2 pin connector, do I just hook the white and red wires to go out?
2. I will be adding a volume knob but lack the proper resistors atm, I suppose I can just add a resistor on the 2 gain pins, any recommendations on what ohm resistor i should use
(I currently have a 470 ohm on it)
3. The biggest issue is the mic isn't picking up my voice, the only time I noticed it pick up anything was when it was sounding like it was being shuffled around it sounds like wind/static all the time. and if I tap it hard it makes a pop noise then goes silent and then after a few seconds it goes back to ambient static/occasional shuffling noise
basically when its just a ambient hum it does not pick up my voice, when there is static and shuffling then it picks up my voice which again is random
I've fully assembled the microphone and pre-amp, yet the sound i am getting from it is no-where usable, it sounds like this:
anyone know what could be causing this?
Edit: I removed the 2 capacitors that are linked to the NMA0515SC and that made it worse, this is making me suspect that it's something with the counterpart I'm using, everything is the same except the USB to analog converter and the voltage booster (i am using a MEA1D0515SC)
I seem to have gotten the microphone to work for the most part but it randomly starts making a static/white noise sound nothings being moved around when this is happening its just happens while it just sitting there.
Anybody got any ideas on what could be causing this
edit: after posting this it started doing it all the time...
This post was modified 3 years ago 2 times by RedRevo117
For those interested, I've made a PCB for the pre-amp, for those who are interested here is the link to the gerber (uploaded to google drive since the forums did not allow me to upload zip files)
This is the first time i have designed a PCB but i am pretty confident I've wired everything up correctly. Feel free to use and improve it
@justalbin I was confused about this too but if you watch the video when he puts the whole thing together you can see the correct orientation of the caps. You seem to be correct about cap 3 and 4. That being said, mine still isn't working correctly.
Hi, I'm new to this and this is my first time trying something like this. What type of audio cabled does He use to connect the copper wire to the stripboard. Also what type of wires does he use for the rotary switch and usb-c power connections, connecting the usb audio interface to the Preamp.
@electronicnewbie The audio cable would be 2 conductor shielded. I ended up using a shielded aux cable I found on amazon. As for the other cable, the usb audio interface comes with a pretty long usb cable and I'm pretty sure that's what he used. You end up cutting it off anyways if you are adding the usb-c, so you may as well put it to use.
Thank you for the pictures. I am a little stuck at this point myself.
My interpretation: The video is correct. The schematic mixes up the polarity of what you call cap 3 and 4. The print layout uses gray half-circles and I think the ones for caps 1 and 2 are inverted.
Your pin-out of the dc converter has a different polarity than in the video. The 15v + and - are reversed. I could not find a source for the pin-out so am assuming the video is correct.
What do other people think? I am no expert and would be very grateful for someone to check my thinking here.
I am also using the J111 transistor and am getting similar results. I see sham had a few solutions for you and I'm wondering if any of them worked for you?
@parker i have a problem with the capsule, when i plugged into the enter, i have a big buzz without any acoustic sound, when a speak into this, i dont have sound which enter.
Can you help me and give me some advice please ?
Its either the capsule or the transistor is faulty
@parker Before I saw his reply, I had already swapped to the transistor he uses in the videos and it made no difference for me, almost an identical result. I tried replacing the two 2200ohm resistors with the 1k resistors and It made the results worse. I am also using a EC1SA05N, but I compared the data sheets and as far as I can tell, they are almost identical. Maybe I'm wrong. These are the parts I am using besides the transistor.
@diyperks Hello, I'm at the end of this mic design project, and I currently have 2 issues, I have to turn in this project by next Monday in addition to that. When I connect my capsule to the input I only receive buzz, yesterday I had sound with my voice for the first time, I don't know why it worked, then as soon as I connected my potentiometer, the buzz has returned. In addition I think I have incorrectly connected my potentiometer, with its 3 connectors, would it be possible to have help please?
For those interested, I've made a PCB for the pre-amp, for those who are interested here is the link to the gerber (uploaded to google drive since the forums did not allow me to upload zip files)
This is the first time i have designed a PCB but i am pretty confident I've wired everything up correctly. Feel free to use and improve it
I have have done something similar but have added a audio out daughter board. I have finally got the main board made and am still waiting fir the rest of the components.
Iv attached some of my designs and the final board.
Microphones are ubiquitous in modern life; they can be found everywhere from your smartphone to your TV remote. However, the audio quality on offer varies wildly depending on their intended use, with studio microphones unsurprisingly being highly tuned to provide pleasant and detailed sound capture... but at a significant cost.
This is fair enough... all that R&D needs rewarding, right? Absolutely, but purchasing a $500 microphone only to find that it uses about $20 of easily-sourced core components is a bit of a painful discovery. This price disparity is one of the key reasons that building a microphone yourself can make a lot of sense. Not only can you customise its design to your specific use requirements, but it can cost significantly less than purchasing one pre-made. It's fun too!
This project covers everything from sourcing a good-sounding microphone capsule to building a frame for it and even including a USB interface so it can be used on any modern device whether that be a laptop or a smartphone.
Hi, I am having difficulty finding the right components for this build, especially with the transistor 2n4416A i am not able to find the same transistor as the one used in the video can anyone help me find a transistor with same specs as the 2n4416A.
There seems to be a mistake regarding the NMA0515SC wired to the 2200uF caps.
12 minutes into the video DIY perks explains the -15 and +15 volt pins but this is the opposite of the schematic. I assume that was a mistake.
What makes this even more confusing, it is negative 15 voltage i should hook up to negative on cap, that means positive on the cap is hooked up to ground whis seems wrong. But is correct?
Can someone confirm that negative 15 volt should go to negative on cap and positive 15 volt to positive on the other cap like my picture.
This post was modified 2 years ago 2 times by tekken
Hi, I have a question about the 22 uF capacitors. In the BOM they are specified as non polarized. In the video radial capacitors were used which to my udnerstanding are mostly polorised and can be quite hard to find non-polorised ones.
Could I use cermaic disc capacitors instead or would that impact the sound quality?
