iPhone / iTouch guitar cable & buffer

Various cables have appeared that allow you to connect your electric guitar to your iPhone or iTouch so you can record or use some of the amp and modeling effect applications. The issue is that the guitar's tone and volume controls are affected by the iPhone/iTouch microphone circuitry. Also the guitar circuitry sometimes doesn't trigger the iPhone/iTouch to switch to the external headphone/mic socket.

The following instructable will show you how to build a guitar buffer and cable that will allow you to connect your electric guitar directly to your iPhone/iTouch's headphone/mic socket.

To build this instructable you'll need to know how to  make a PCB (I used the toner transfer method) and some understating in basic electronics. You could also build it on strip board instead of making a PCB.

Step 1 Circuit diagram of the buffer.

The circuit runs of a single 9v transistor battery. When a 1/4 inch plug is inserted it turns on the power to the buffer. I used a high brightness blue LED for the power indicator so I could get away with only using around 1mA for the LED. This means that the whole circuit uses around 10mA or less when running.

The terminals I/P means input and O/P means output.
I haven't included the power diode in the circuit that prevents damage if you connect the battery around the wrong way. I'll show the diode in the wiring diagram.

Comments

[skippydownunder]

Nice work to you have the updated board file brd the attached is slightly different to the pdf.

[cealac]

does it works with a bass guitar?

[screenryan]

I think I'll try this out this weekend, but I have a question. Your wiring diagram shows a diode, but the schematic doesn't show where the diode goes. Can you clear this up?
thanks

[slemke]

The diode was added to protect the circuit if you try and clip the 9V battery around the wrong way. It was an afterthought as I built the project for someone else and I didn't what the circuit damageg IF the battery was put in th wrong way (I know it's hard to put the battery in the wrong way) but stranger things have happened....

[gbgeorge]

THANK YOU!!

I have been searching for a DIY irig/ampkit for a while and i think your tutorial is what i was looking for! :)

is there any clippings/distorions when you use this kit on your iphone/ipod/ipad? like unpowered irig does?

[slemke]

I don't play the guitar but the guy I built it for uses it on his iPhone 3s and hasn't had any clipping. You can adjust the output via the variable resistor (pot) on the PCB. If you do get any clipping just turn down the output. One thing we did find was that fluff gets into the iPhone headphone jack and can make things noisy or the plug doesn't go all the way in. So once in a while check your headphone jack in your iphone/ipod with a torch to see if there's not a build up of fluff / dust.

[Electric Jesus]

Hi, is there a bigger wiring diagram? It's too small on step #3.. :( just wanna make sure

[bloke2022]

Just hit the little "i" in the top left corner, then click the largest file size.

[vignesh1230]

Can you please post all of the components that you have used? The shematic is a lil confusing for me since im 13. And does this have impedance matching like the iRig?

[shteef]

Your a hero, my son is learning to play the electric guitar, and wanted a couple of effects pedals for xmas, I have seen various "apps' on iTunes that when combined with your gizmo, will do the job of effects pedals.
You have saved me money and given me a little project.
cheers ears!

[thewizard42]

As your son gets better, and i do hope he does, guitar is like my life haha, he should get actual stompboxes, which if they are analog, they can be easily made.