Hi, I'm a musician with some electrical engineering knowledge. I want to put together some pro-quality recording microphones. I don't want a preamp, but wish to record multiple instruments directly to my computer. Here is the schematic I'm using.
1 a) What type of cable connector should I use, XLR or USB? If I use XLR, I need to know how to diy an XLR to USB converter. USB should be fine as I won't be recording while listening through headphones.
b) How would I connect that cable to the mics?
2) How will I get it to send the input from all the mics to my computer using a single cord?
Thanks a bunch!
1 a) What type of cable connector should I use, XLR or USB? If I use XLR, I need to know how to diy an XLR to USB converter. USB should be fine as I won't be recording while listening through headphones.
b) How would I connect that cable to the mics?
2) How will I get it to send the input from all the mics to my computer using a single cord?
Thanks a bunch!
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An external USB sound card will be very good, but it isn't something you want to build. Buy one of the many, or use the mic input your computer already has. It will be a small 1/8" inch jack. USB is strictly a digital interface.
For multiple inputs you need a mixer of some sort to blend the various mics into one or two channels. That you could build, or buy. The Behringer RX1202FX or similar thing is usually cheap, there's about a million similar gadgets out there, or an opamp summing circuit is pretty easy to make.
I'd put the circuitry right at the mic, then bring the higher level signals to the mixer.
I have to comment on the mic and circuitry. A cheap condenser mic and a 741 are not going to give you anything near "pro-quality". Even the Panasonic condenser mics often suggested as measurement microphones might prove disappointing in terms of signal to noise ratio. There's a mic building forum on Yahoo you might find interesting, though some of those people are really hard core!
For multiple inputs you need a mixer of some sort to blend the various mics into one or two channels. That you could build, or buy. The Behringer RX1202FX or similar thing is usually cheap, there's about a million similar gadgets out there, or an opamp summing circuit is pretty easy to make.
I'd put the circuitry right at the mic, then bring the higher level signals to the mixer.
I have to comment on the mic and circuitry. A cheap condenser mic and a 741 are not going to give you anything near "pro-quality". Even the Panasonic condenser mics often suggested as measurement microphones might prove disappointing in terms of signal to noise ratio. There's a mic building forum on Yahoo you might find interesting, though some of those people are really hard core!
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Hi Conrad,
I read on eHow that 1/8 inch mics are "rarely used for musical purposes due to lower quality resolution."
I'll be editing the audio files on my computer, so isn't digital preferable? Do I need an analog to digital converter; isn't an external USB sound card essentially this?
Sorry, I'm confused. Higher frequencies?
Regarding the quality of the circuit, the author of the link I posted was sure boastful. Condensers are the most used in recording studios. Should I build a dynamic instead?
I read on eHow that 1/8 inch mics are "rarely used for musical purposes due to lower quality resolution."
I'll be editing the audio files on my computer, so isn't digital preferable? Do I need an analog to digital converter; isn't an external USB sound card essentially this?
Sorry, I'm confused. Higher frequencies?
Regarding the quality of the circuit, the author of the link I posted was sure boastful. Condensers are the most used in recording studios. Should I build a dynamic instead?
The sound is analog and the signal coming out of the microphone is analog. The amplifier signal coming out of the opamp is analog. The only way it becomes digital and editable in the computer is via a ADC (analog to digital converter). That's what a sound card, be it internal or external is. After messing about with it in the computer you then need a DAC (digital to analog converter) to get it back in analog form to feed to a speaker. Again, this is part of the sound card. Unless you use an external sound card, there's no USB involved here- that connection can't deal with analog signals at all.
There are USB mics sold that have the ADC built in and do plug into a USB port, but that's not something you'd typically attempt to build.
The signal from the mic is very small. After being amplified by the circuit, the 741, it becomes a "high level signal", i.e. a signal that's bigger and more useful. The 741 is a very old opamp and not generally considered adequate for quality audio work, though for some things it's good enough.
1/8" mics are very small and not high fidelity. 1/4" mics are better, but you really need to go with 1/2" mics for any kind of quality. Serious studio mics use much better mic cartridges (I hope) and many are a full 1" diameter diaphragm. You can build something quite useful, but it's probably not going to equal a $$ studio condenser mic.
There are USB mics sold that have the ADC built in and do plug into a USB port, but that's not something you'd typically attempt to build.
The signal from the mic is very small. After being amplified by the circuit, the 741, it becomes a "high level signal", i.e. a signal that's bigger and more useful. The 741 is a very old opamp and not generally considered adequate for quality audio work, though for some things it's good enough.
1/8" mics are very small and not high fidelity. 1/4" mics are better, but you really need to go with 1/2" mics for any kind of quality. Serious studio mics use much better mic cartridges (I hope) and many are a full 1" diameter diaphragm. You can build something quite useful, but it's probably not going to equal a $$ studio condenser mic.
You said pro quality, so do it the pro way. You have to capture the sound, that is what a microphone does. Some little radio Shack condenser mic capsules might sound OK, but they are not remotely professional quality. And Conrad is certainly correct that the 741 op amp is ancient history, there are far better contemporary choices.
As Conrad also pointed out, USB is strictly a digital connection, you would not get anything wiring a microphone to a USB cable.
Microphones that come with 1/8" plugs are indeed cheap mics of limited performance, but that isn't the connector's fault. If you wired a good mic to a 1/8" plug and connected it to a good sound card, it would sound good.
How will you be recording the sounds once they are in your computer? There are high quality recording software packages. And they anticipate the need to get sound signals into the computer, so a number of companies make audio I/O interface units.
There are USB mixers. You can plug several microphones into one, as with any mixer, but it has an additional USB output so you can send the mix directly into a computer. Here is just one choice from many:
Peavey PV6 USB | Sweetwater.com
As Conrad also pointed out, USB is strictly a digital connection, you would not get anything wiring a microphone to a USB cable.
Microphones that come with 1/8" plugs are indeed cheap mics of limited performance, but that isn't the connector's fault. If you wired a good mic to a 1/8" plug and connected it to a good sound card, it would sound good.
How will you be recording the sounds once they are in your computer? There are high quality recording software packages. And they anticipate the need to get sound signals into the computer, so a number of companies make audio I/O interface units.
There are USB mixers. You can plug several microphones into one, as with any mixer, but it has an additional USB output so you can send the mix directly into a computer. Here is just one choice from many:
Peavey PV6 USB | Sweetwater.com
Hi Jason
What is the quality level you are shooting for? It is possible to build very high quality clones of famous microphones (think $2000+ mics for about $600 in your country): see the video here, for example: Building a Vintage-style U87 Mic Is Easier and Cheaper Than You Think (Video)
You will also find some good tips and tweaks on recording equipment communities, which have a very active DIY group as well - and no, it's not just microphones, lots of hardware and outboard effects too 🙂
However if all you want is to do some basic recording, get yourself a 3-pack of Behringer, Wharfedale or Samson mics. You will need a mixer and an interface. I use a small Behringer mixer and this is connected to a m-Audio soundcard for A/D conversion. You could also get a Focusrite 2i4 that will allow you to connect up to two microphones simultaneously and it uses a simple USB connection to get the sound in and out of the PC. No separate A/D or D/A is required, You can connect monitors and headphones directly to the Focusrite. There are plenty of other entry-level USB products and those plus some cheap dynamics will be better than DIY'ing a condenser mic.
That preamp is terrible for recording anything but speech to a tape recorder. It uses capacitor coupling, low phantom power supply voltage and probably terribly noisy. You would be well-advised to invest your time in making music and buy products off the shelf if your ambitions are lower than the super-premium clones.
In the end, DIY never saves you money/is never cheap. Whichever side of the music it happens to be on.
What is the quality level you are shooting for? It is possible to build very high quality clones of famous microphones (think $2000+ mics for about $600 in your country): see the video here, for example: Building a Vintage-style U87 Mic Is Easier and Cheaper Than You Think (Video)
You will also find some good tips and tweaks on recording equipment communities, which have a very active DIY group as well - and no, it's not just microphones, lots of hardware and outboard effects too 🙂
However if all you want is to do some basic recording, get yourself a 3-pack of Behringer, Wharfedale or Samson mics. You will need a mixer and an interface. I use a small Behringer mixer and this is connected to a m-Audio soundcard for A/D conversion. You could also get a Focusrite 2i4 that will allow you to connect up to two microphones simultaneously and it uses a simple USB connection to get the sound in and out of the PC. No separate A/D or D/A is required, You can connect monitors and headphones directly to the Focusrite. There are plenty of other entry-level USB products and those plus some cheap dynamics will be better than DIY'ing a condenser mic.
That preamp is terrible for recording anything but speech to a tape recorder. It uses capacitor coupling, low phantom power supply voltage and probably terribly noisy. You would be well-advised to invest your time in making music and buy products off the shelf if your ambitions are lower than the super-premium clones.
In the end, DIY never saves you money/is never cheap. Whichever side of the music it happens to be on.
The sound quality should be as high as possible, given I can afford it. I could spend a couple hundred dollars if I have to, but hopefully I'll succeed at making a pro mic for much less. Really, all I need is to record music directly to my MacBook Pro, probably through GarageBand. (Even though time is $$, I at least really want to know exactly what it would take to build my own pro mic array before I would decide to buy one instead.)
Instead of a 741 I could build this: Op Amp Circuit | Electronic Circuit Design
What is a mic cartridge, and how can I tell if one is better than another?
I was actually unaware of the need to make a diaphragm. Where would it fit into the schematic?
When talking about mics it seems 1/8" and 1/4" refer to cable size, but 1/2" and 1" refer to diaphragm size?
Thank you all for your time! 🙂
Instead of a 741 I could build this: Op Amp Circuit | Electronic Circuit Design
What is a mic cartridge, and how can I tell if one is better than another?
I was actually unaware of the need to make a diaphragm. Where would it fit into the schematic?
When talking about mics it seems 1/8" and 1/4" refer to cable size, but 1/2" and 1" refer to diaphragm size?
Thank you all for your time! 🙂
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Well, yes, there is that bit of confusion. 1/8 and 1/4 of an inch are common connector sizes. COndenser mics generally are described by their capsule diameter among other things.
Your schematic is a very basic microphone preamp. it requires a signal input from a microphone of some sort. They added R1 to provide operating voltage for an electret microphone capsule. They provide radio Shack part numbers for the capsule and other parts. I have no idea if radio Shack still sells all those things. They might.
A microphone is a piece of equipment - the thing a singer picks up and sings into. The microphone capsule or element or cartridge (and maybe a few more names) is the actual working part inside the microphone. You can buy microphones, or you can buy just the inner capsule.
Here are some things that might be of interest:
An Introduction to USB Microphones | SweetCare
What is the difference between Dynamic and condenser microphones? | SweetCare
Microphones : Frequently Asked Questions (FAQ) | SweetCare
Then that circuit is out of the question now.
However, I recently found what I really need: http://www.gearslutz.com/board/atta...uild-your-own-microphone-capsule-rwillmic.pdf
RadioShack does have a good selection of electrical components. Their mic element must not be high quality because it's only $3. Anyway, I just hope I can get all the materials I really need now.
However, I recently found what I really need: http://www.gearslutz.com/board/atta...uild-your-own-microphone-capsule-rwillmic.pdf
RadioShack does have a good selection of electrical components. Their mic element must not be high quality because it's only $3. Anyway, I just hope I can get all the materials I really need now.
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Very Cool Article, Thanks for posting that!!!
I will have to give that a try sometime.
Ribbon microphones are rather easy to build and from what I have read on some of the DIY versions I have seen there quality is very high.
Meanwhile these little modules from Analog devices ADMP411 (now sold to InvenSense) may spark some interest as well,
InvenSense | MEMS Sensor System on Chip | ADMP411
http://www.invensense.com/mems/microphone/documents/ADMP411.pdf
Specs,
• 4.72 × 3.76 × 1.0 mm Surface-Mount Package
• High 131 dB SPL Acoustic Overload Point
• Sensitivity of −46 dBV
• ±2 dB Sensitivity Tolerance
• Omnidirectional Response
• High SNR of 62 dBA
• Extended Frequency Response from 28 Hz to 20 kHz
I have some of these from AD before they got sold, But I haven't hooked one up yet. 😉
FWIW
jer 🙂
I will have to give that a try sometime.
Ribbon microphones are rather easy to build and from what I have read on some of the DIY versions I have seen there quality is very high.
Meanwhile these little modules from Analog devices ADMP411 (now sold to InvenSense) may spark some interest as well,
InvenSense | MEMS Sensor System on Chip | ADMP411
http://www.invensense.com/mems/microphone/documents/ADMP411.pdf
Specs,
• 4.72 × 3.76 × 1.0 mm Surface-Mount Package
• High 131 dB SPL Acoustic Overload Point
• Sensitivity of −46 dBV
• ±2 dB Sensitivity Tolerance
• Omnidirectional Response
• High SNR of 62 dBA
• Extended Frequency Response from 28 Hz to 20 kHz
I have some of these from AD before they got sold, But I haven't hooked one up yet. 😉
FWIW
jer 🙂
Attachments
While I wouldn't call the mechanical aspect of a ribbon mic particularly easy, it will also need an impedance converter/preamp in the mic housing that is very far from easy.
Behringer or Roede condenser mics are cheap and reasonably good quality compared to the larger brands. Buy the mics and a multichannel external USB sound card and get going. Mic building is certainly for the enthusiast full of patience, and you will end up spending a lot more money than buying them as I suggest.
BTW - you say you don't need preamps, but you certainly do need them for mic's, unless you use a regular mixer and feed the stereo signal directly to a PC sound card, - internal or external.
Behringer or Roede condenser mics are cheap and reasonably good quality compared to the larger brands. Buy the mics and a multichannel external USB sound card and get going. Mic building is certainly for the enthusiast full of patience, and you will end up spending a lot more money than buying them as I suggest.
BTW - you say you don't need preamps, but you certainly do need them for mic's, unless you use a regular mixer and feed the stereo signal directly to a PC sound card, - internal or external.
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Here are some really cool links on how to build your own High Quality recording Mic's!!!
For a fraction of the cost!!!!!
Microphone Capsules and Mod Kits | Microphone Parts
VintageMicrophonepcbkit.com
Building a Vintage-style U87 Mic Is Easier and Cheaper Than You Think (Video)
http://store.studio939.com/product/35mm-k67-style-capsule
Enjoy!!!!
jer 🙂
For a fraction of the cost!!!!!
Microphone Capsules and Mod Kits | Microphone Parts
VintageMicrophonepcbkit.com
Building a Vintage-style U87 Mic Is Easier and Cheaper Than You Think (Video)
http://store.studio939.com/product/35mm-k67-style-capsule
Enjoy!!!!
jer 🙂
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Here is some great info on DIY ribbon Microphones,
http://www.diyaudiocomponents.com/ribboninfo.php?sub=1
jer 🙂
http://www.diyaudiocomponents.com/ribboninfo.php?sub=1
jer 🙂
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