Make a cable to use your iPhone or iPod Touch as a guitar amp

Welcome to my first instructable and it's not very good, so consider yourself warned.

If you own an iPhone or an iPod Touch and happen to be a guitar player chances are you have already heard of either GuitarBud by PRS or of iRig by Amplitube.

Both products allow you to connect your guitar to your iPhone or iPod Touch and use it as a practice amplifier via their own apps or any others that can do the same. Isn't technology fun and useful? It's also expensive and hard to find especially in Portugal.

Inspired by these products I decided to do my own version, only much cheaper and not as nice looking. On the next steps I will try to explain how to make your own cable.
If you don't understand anything feel free to contact me or ask in the comments I will try to make it clearer.

Step 1: Things you need

Despite the street prices of these things they are actually pretty simple and cheap to make here's what you need.

- 1/4 inch female mono jack socket. This will be used as the input for your guitar.
- 1/4 inch male stereo jack socket or a 3.5mm stereo female jack socket. This will be the output, headphones go in here. I used the 1/4 inch because I had it laying around along with a 1/4inch to 3.5mm adapter, if you prefer you can use the 3.5mm and spare yourself the adapter.
- 3.5 mm stereo video cable. The most important part.

In the last picture you can see three cables the white one came with my iPod Touch and has a built in microphone, the black one are my headphones that lack the built in mic, and the grey one is the one we'll be making.

This is why we need the 3.5mm stereo video cable, it has the same lugs as the white one. One for the mic (in this case the guitar input), and two for the headphones (in stereo were available).

Comments

[WickeD12]

hey i have an android 2.2 and i was thinking of getting a cable that one end you plug into guitar other into ur phone... its like 3 bucks (NZ) in bond&bond but i still dont know about the app to add distortion etc? can anyone help???

thanks

[Exiumind]

Boas! Onde arranjaste esse cabo e quanto custou?
Eu preciso de uns como esse para uns monitores de carro, audio e video no mesmo cabo =)

[thejedilestat]

ihave to try this

[ivaneduardo747]

You say I have to chop those cables off with an axe.
But I have no axe!

[airjest]

Use a sword instead...lol

[cursesusernamealreadyinuse]

I guess you can use a chainsaw, but an axe is really all you need.

[son of s8an]

My axe is a fender! ... oh you mean a real axe.........

[Kevin11721]

A more elaborate circuit here.

http://sgitornado.altervista.org/diyirig.html


Active balanced signal.

[Kevin11721]

Deal extreme has that AV cable for $2. Including shipping from China. Takes weeks though.

[iraklilion]

Hello, can you send me the schematic of this? I cant understand a lot from this pictures. pleas send me schematic. I have 4 pin audio conector only I dont know which wire where would be soldiered. thak you.

[H4ZZ498]

Would it be possible to make this without the sockets? I am happy to crocodile-clip my leads in. If so, how would I wire it up?

Thanks,
~H4ZZ

[mintar]

Do you know SVJ, aren't you the winner of this month?

[cursesusernamealreadyinuse]

SVJ?
Don't think I do, but the again I'm getting old and senile.

Is/are he/her/they on instructables?

Winner?

Yep, I'm clueless.

[mintar]

SVJ (Sciences & Vie Junior) is a french magazine.
Every month, there's a giveaway for an invention. Last month, the winner made the same thing and won 1000€!

[arte.sano]

Thanks for the ible, works pretty well!. I went a different route tho. I use a discarded headphones with mic but same concept, I did use your idea for the housing with the canister, brilliant!.
cheers.

[mwseniff]

I originally got the PRS connector and it sounded terrible with IK-Multimedia Amplitube as well as the new Ampkit apps on my iPod touch. It definitely had issues with the input impedance mismatch. I recently got the Peavey/Ampkit iLink interface and it is a drastic improvement. The iLink is actually active and runs on 2 AAA cells it solves the impedance and feedback like problems of the PRS interface (I have not tried the iRig interface as they were very slow on delivery). I then went back and tried the PRS interface with both a compressor and a clean boost pedal set very clean and that seemed to solve a lot of problems. I believe that incorporating an opamp IC or a discrete transistor circuit into the interface would help immensely with the overall sound quality. In any case the iPhone/iPod touch are great for guitar when I am stuck in bed. Then I added a Vibe-it speaker device (makes any large hollow object into a speaker) stuck to the guitar and it makes beautiful controlled feedback like having an Ebow on every string. I also have hooked the interface output to my bedroom guitar amp (Ampeg Gemini II from the 60's) and it works very well.

[ivaneduardo747]

I has thinking on doing this too, but I was afraid of frying my iPod or worse, using my guitar's pickups as speakers anfter wiring using a bad pinout.

[dirq]

You should probably mark the wires before you chop the connectors off. Then you'll know what to solder later.

[mbrameld]

@dirq If you look at the pictures you'll see that the wires inside are colored to match the connector they were formerly attached to.

[alexanderm]

You've got some serious impedance mismatching.
Basically, you are over-simplifying the electrical circuit.
Here's how to fix it (there are a few other ways that might sound better, though... but this is, essentially, what they are using in most of the commercial products):

Use a 2.2kohm resistor >1/8W and a 0.01uf capacitor >10V (not an electrolytic) wired in parallel with each other, wired in-line on the guitar input signal wire.

This should correct the impedance mismatch, if i've got my figures right. Someone else did the figuring, too, and came up with the same numbers, so i'm fairly sure they'll work. Should be a pretty easy fix, too... and, it should significantly help the tone and volume issues most of you have had. i'm thinking you may even be able to wire the components into one of the jacks, essentially making it appear like a basic cable. The 1/8" TRRS jacks are actually available from a number of parts suppliers for just a few bucks, and you could use higher quality wire for a very professional-looking cable.

The best option with regards to fidelity might be to use a small transformer for the task, but that's still going to require some electrical tweaking, would be bulky, and it might be hard to find the right transformer. i'd recommend getting quality caps and resistors... i know Parts Express carries some quality ones at great prices. No, i don't work for them! My company sells them, too, but i'm opting to not give a shameless plug for a 50-cent part. That said, if anyone wants my custom cable company to custom build you one of these cables to spec, check out the Facebook page for Gestalt Audio, and message me. i'm putting this in my list of "Projects i'll Eventually Get Around To" since i've already got all the components in my cable shop. Now just to find some free time for a personal project! If i wind up making one (personal or professional project), i'll consider making an Instructable on it.

Good luck. Let me know if it worked correctly for you.

[genghistron]

Tried the basic cap and resistor method you mentioned and it worked but its noisy and the tone still seemed very 'sucked out'. Got better results with 3.9Kohm resistor (instead of 2.2K).

One big point of interference is the pots in the guitar, they are microphonic and can cause some interesting behavior on the phone using this circuit. (turning my volume pot all the way down activates Voice Control on the iPhone). I believe this is because the simple RC circuits doesn't provide any DC isolation.

http://www.diystompboxes.com/smfforum/index.php?topic=85913.0

Waiting on an order with some appropriate JFET's to test the circuit above. If it works out well I'll post an instructable.

[Eganov]

First, great post! Love it. However, if you have an old set of iPhone headphones with handsfree chop the phones an use that as guitar input and phones output.

[genghistron]

Heads up,
iphone/ipod phones use very fine stranded, coated wire that is a real headache to deal with. Better off using an old AV cable. I had a cheap USB connector for an ipod shuffle (just a TRRS plug to usb, no dock like the apple branded ones), the higher gauge wires were alot easier to manage.

I'm doing a build this week, I'll try the resistor/cap method described in the first post, also this schem looks promising and allows an adjustable input to find that tone "sweet spot"
http://www.diystompboxes.com/smfforum/index.php?topic=86451.0

[pancake flavoured waffles]

could you possibly enlighten me on how to make my own 1/4 inch female socket? i need to make a modified version of what you have here. just a 1/4 female that leads to a 3.5 mm male.

[pancake flavoured waffles]

please? i just need some schematics.

[cursesusernamealreadyinuse]

Hey Waffle sorry for the late reply, but I forgot to check my comments. That should be easy, the components depend on what you want to do. You need a female 1/4inch socket but you might need a stereo or a mono one. If you check the pictures the mono one as two lugs (that's were you connect the wires), but a stereo one has three. The same is true for the 3.5mm jacks or sockets. The stereo ones are used for the headphones (because you have two speakers) the mono for the guitar. If the 3.5mm jack is stereo you need a stereo female jack. These adapters are easy to find in shops plus they are cheap and small. If you still want to go the DIY way tell me what components do you need and I'll give a schematic. Altough usually for these type of things I prefer to buy a ready made adapter.

[slemke]

The AV cable you purchase must be one suitable for an ipod. Don't buy an expensive one as you may as well go and buy a ready made guitar cable. The standard 4 pin AV cables used on Nokia phones, portable DVD players etc have the sleeve of the 3.5mm plug connected to the shields of the coax cable and the 3 RCA plugs outer rings. Apple decided to use the sleeve of the 3.5mm plug as the microphone. See this link to explain:- http://pinouts.ru/PortableDevices/iphone_headphone_pinout.shtml The 3 AV cables I had lying around where not suitable (they were from a DVD player, camera & phone). They were all wired the same as this link:- http://pinouts.ru/CellularPhones-Nokia/nokia_n95_tvout_pinout.shtml

[bneboys]

hey how do I tell if my av cable will work?

[slemke]

It seems that the ones that claim to work with camcorders are wired differently to the DVD or Nokia phones. Another thing to consider is this, the iPhone or iTouch will not switch to the external microphone input inless it can see around 1000-3000 ohms resistance. Your guitar "may" present this resistance or it may not. Your guitar may also overload the microphone input of the iPhone/iTouch if your guitar puts out too much level. I have built a guitar buffer that inputs into the iPhone for a friend which I'll post on Instructables soon. It provides the correct resistance the iPhone/iTouch is looking for to enable input switching, it also isolates the guitar so the tone controls work as normal and the level can be adjusted so the guitar doesn't overload the input - but it requires you to build a circuit board. Stay tuned.

[jeipiyaku]

thanks for this tutorial! i tried to create this but after i completed the guitar socket while recording i received a loud pulsating noise together with the sound of the guitar im sure it is not from the guitar because i tried it in my amp do you know anything that can help me remove the noise?

[zirconiumeffect]

you can buy a adapter that fits in a guitar, and you can plug a audio cable extenstion, then plug whatever you want to into the audio cable,....

[Nathan_h]

Cool project. There is a new app now in the store called amplitube which is also worth trying. But the tone control idea is on the right track to the wrong solution. Ithink it's impedance that you want to alter not tone to get the right kind of guitar sound.

[blodefood]

Could you use small speakers instead of earphones?

[roycetaft]

Cool! I had the same Idea last Thursday. I and for a different project I also used a film canister for a 1/4" jack. Very interesting.

[cursesusernamealreadyinuse]

Cool! Did you make a cable too? Film canisters are very handy stuff, sturdy, easy to cut and drill best of all quite cheap and easy to find.

[roycetaft]

Yes, I made an extension cord and didn't have the fancy female jacks that come with an enclosure and as you said, a film canister was a perfect make-shift enclosure. Ha ha, I re-read my earlier comment and noticed the beginning of the second sentence. Oops.

[wolftracer]

This is a great idea. However instead of all of the soldering you could just use rca adapters instead of the 1/4 jacks. An rcaF to 1/4" F on the red and a 2-rcaF Y to a single 1/8" stereo Female. But, using a small enclosure to house it all would be good too. You could actually make the enclosure the RCA -1/4 connector and the Y by using 3 RCA F on one side and the 1/4" mono and the 1/8" stereo on the other side so that you aren't limited in case that cable end craps out.

[cursesusernamealreadyinuse]

Thank you. I toyed with the idea of using adapters inicially, but couldn't think of the ones I needed (now I know). Three main reasons why I didn't use the adapters: 1 - They would make the project a bit more expensive and I already had the 1/4 inch jack sockets laying around the house. 2 - Soldering isn't that hard and a very handy skill, since the holes in the lugs of these jack sockets are quite large it makes it very easy if you lack experience soldering. Plus every guitarrist should know how to solder, it's easy, fun and it saves you some bucks. 3 - It's a personal reason. I carry this cable around with me, on my guitar case, backpack, even my pocket, the adapters would make it a tad bulkier and heavier. Your suggestion is a very nice alternative and it may be the solution to some folks here. Thank you. I'm thinking about updating the instructable with the suggestions provided by others, that way it saves the trouble of looking in the comment section.

[LeviMan_2001]

Hey, cool ideas. I wish I had an iPhone to try this with, but I can tell you why it sounds bad in voice memos. The reason is that the guitar's magnetic pickups really like to pick up middle frequencies more than bass or treble. What you could do is wire up a tone circuit that takes those middle frequencies and dips them down to be more even. That's what regular guitar amps do.

[cursesusernamealreadyinuse]

You are right, guitars do love mids. The tone control is an interesting idea, and it shouldn't be too hard, however I found that if you use an app that simulates amps, you get a very decent sound. Not a sound I would use to play live or even at home, but more than enough for a practice amp.