Guitar/Mic In Port

 by btop
ever seen those USB boxes that you connect your guitar into and it gives you a nice little port? Pretty nifty, but a bit pricey. Here one you can make for ~�1
 
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Step 1: What You Will Need

For this, you will need

A 1/8 jack for your guitar, or any other jack you want.
A drill and appropriate bit.
An analogue computer sound cable (mine was from an old CD drive).
Soldering Iron.
Bonejamin says: Sep 22, 2009. 7:31 PM
If you want to play along with the songs on your computer without disturbing your family or the neighbors, you can do what I did. You'll need 2 inexpensive things: 1. A "Y" cable with at least two 1/8" stereo jacks connected to one 1/8" stereo plug (I used an extra 3-way extension which came with my computer that has one 1/8" stereo plug connected to three 1/8" stereo jacks). 2. A 1/4" female to 1/8" male stereo plug adapter. Plug one end of a guitar patch cord into the 1/4" headphone jack of your guitar amp or direct box (if it has an 1/8" jack, just get another 1/4" to 1/8" adapter, although this adapter doesn’t have to be stereo). Plug the other end of the patch cord into a 1/4" to 1/8" stereo adapter plug. Connect this 1/8" stereo plug and your headphone 1/8" plug into the jacks of the "Y" cable (if you are using one like mine with 3 extensions, just leave the third jack empty). Now connect the 1/8" plug from the "Y" cable directly into your computer headphone jack and jam away! NOTE: It's important to use a stereo "Y" cable and a stereo adapter even though the patch cord from the amp can be mono. Otherwise the mono plug adapter and/or mono “Y” cable will cause the songs and your guitar to only come through one of the headphone speakers. You can certainly use a stereo cable to run from your amp (or direct box) to “Y” cable; but since most amps send a mono signal anyway, and since patch cords are cheap, I went this route.
Guitar hookup.jpg
drigo_kmp says: Apr 18, 2009. 2:32 PM
It's a nice idea, but you can't just connect a guitar o bass guitar into it. Guitars and such have a high impedance line level and the aux input that sound cards have has a low impedance mic level. This means that you will easily fry something, more likely your sound card. To connect a guitar line to a mic input or low impedance level input you need a devise called "Direct Box" (http://en.wikipedia.org/wiki/DI_unit) that matches the level first (level, not impedance). This is typically used in professional audio to connect guitars or bass guitars directly to a mic input in a mixing console.

And if you want it to be stereo, you need to buy a stereo jack. It's just like the one you used, but it has ground, left and right. That way you don't solder left and right together, which gives you mono anyway.

It will work perfectly for a mic or a mp3, just make sure you don't plug a guitar directly into it though. ;)

Really cool idea, I'll be making one for my computer in a few days.
jzellis says: Sep 29, 2008. 2:28 AM
If your sound card already has a 1/8" input, wouldn't it just be easier to run an 1/8th male to 1/4" female and mount the female end on the front bezel? No soldering required. Though it might be useful to have a gain knob in-line and mounted on the port, to keep people from accidentally plugging "hot" inputs into this and frying the sound card. Cool idea, though, definitely!
btop (author) in reply to jzellisNov 3, 2008. 12:14 PM
I did do that, but was a bit of a clutter, I'm trying to cut down on all the wires.
pbawesome in reply to btopJan 30, 2009. 7:37 PM
i went to radioshack got a 1/4 to 1/8 and phenominal quality only$1.50 no opening case also works to plug in mp3 player to amp if you dont have 1/8 port on your amp for mp3 in
aaronscottaugustinhotmail.com says: Jan 17, 2009. 9:53 AM
great instructable but 1/8in input jack is your standard head phone / mp3 jack you need 1/4 in jack for guitar cables
madmanmoe64 says: Oct 5, 2008. 2:19 PM
Long time since I've opened an amp up, how is it easy to put a gain knob in, where could I find out how?
shutdown_exploded in reply to madmanmoe64Dec 10, 2008. 2:06 AM
are you positive you use the reference design? It seems like the output on the little gem would be too much for the soundcard, as it can drive a small speaker itself, I've heard of several people frying their soundcards in similar ways
johnson_steve says: Sep 27, 2008. 12:27 PM
I hate to be a negative nancy here, but this won't work with a lot of computers. I did this before (with 4 guitar inputs) in this same way. a lot of computers don't have an aux in they only have a cd in and this expects a line level input not a high impendance guitar signal. also feeding a guitar signal directly into a soundcard will result in crappy sound quality as all the emi from the computer gets amplified with the guitar signal. I put a guitar jack like this on my little brothers computer except it has a small pre-amp made from a lm386 (Google 'little gem guitar amplifier') which runs off 12v from the computer psu. this preamp is wrapped in electrical tape and tin foil; the tin foil acts as a Faraday cage blocking the emi from the computer and stopping it from getting into the guitar signal. this results in a very nice and professional sound.
MrRedBeard in reply to johnson_steveOct 1, 2008. 9:09 PM
If you're really worried about sound quality you can purchase a multi-input card, made for studio use, relatively cheap that has 1/4" jacks. BEHRINGER makes some decent products. Wrapping the unshielded areas with tin foil is a good idea but I recommend using aluminum duct tape. This setup is great if you have something like a Line6 Guitar Pod (I use the bass pod and this setup works great). Anything with a line out will work but you might be able to get away with using an effects pedal as long as you don't crank the levels too high. Someone else asked why not use jack adapters: The jack its self weakens the signal and adapters can only make it worse so using a direct connection may clean up the sound.
johnson_steve in reply to MrRedBeardOct 1, 2008. 9:55 PM
I've got a $400 studio card a $100 rackmount preamp a direct in box for the guitars and 4 sure mics to mic up a drumset. all connected to a dedicated headless linux computer (also rack mounted) I'm anal about quality. I build and sell custom guitar amps and effects it is quite possible to make a nice preamp youself and get close to the sound quality of my rig with a standard soundcard. for about $10 and record 2 channels at once.
MrRedBeard in reply to johnson_steveOct 2, 2008. 6:46 AM
What are you using software wise? I've been using Sonar but I find it very processor intensive.
johnson_steve in reply to MrRedBeardOct 2, 2008. 12:08 PM
Ardour on Linux. I canrecord 8 tracks at 24bit digital 96khz at the same time.
johnson_steve in reply to johnson_steveOct 1, 2008. 11:37 PM
BTW: I didn't mean to dis this instructable especially since I doubt I will be able to put together one as detailed and well documented with good pics to boot.
PetroleumJelliffe in reply to johnson_steveSep 29, 2008. 10:35 AM
I'm with Roryok. Let's see how to do that!
johnson_steve in reply to PetroleumJelliffeSep 29, 2008. 10:41 AM
I think I will. It's going to take me a while as I'm very busy and don't have a camera right now. I have a $400 mAudio sound card for recording but there are probably other people that would like to DIY as cheap as possible.
PetroleumJelliffe in reply to johnson_steveSep 29, 2008. 11:11 AM
http://makezine.com/09/crackerboxamp/

The little gem was used to make the crackerbox amp in Make issue #9, I believe.
roryok in reply to johnson_steveSep 29, 2008. 4:14 AM
@ johnson_steve Would you be willing to post your own instructable on how to do this? it would be a cool addition
sound91 says: Oct 1, 2008. 5:54 PM
in step 5 you said that you soldered the left and right together to get stereo, but in reality you just made your signal mono.
Noodle93 says: Sep 30, 2008. 10:12 PM
The reason why people buy those little 'USB boxes' is because they have a built-in sound card designed for guitars. Most soundcards built into computers are pretty cheap and pretty much just for a cheap little microphone to talk with.
wazupwiop says: Sep 27, 2008. 11:37 AM
cool
btop (author) in reply to wazupwiopSep 27, 2008. 11:39 AM
Cheers.
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