Input options and microphones

[jorgren]

I have the Belkin TuneTalk and it sounds pretty good with my iPod Touch. Unfortunately it blocks the earphone port and is incompatible with my Otter case. I have only tested it with the Voice Memo and iProRecorder apps.

I have developed a guitar cable that sounds very good with the same apps. It turns out the mic input on the Touch (and I assume the iPhone) requires a pretty hefty signal; passive (resistor-only) circuits produced a wimpy recording and sucked the guitar's tone. My cable uses a JFET and sounds very good, plus (unlike any I've seen online such as the PRS/Bond GuitarBud), it blocks DC from your guitar, which prevents those nasty crackles and pops. The iPhone/Pod provides +2.8V, intended to power the preamp in their earbud mic. If you put that into a guitar's circuitry, it causes sparks in the controls and connectors, which produces nasty crackles and pops. The cable should work equally well with any electric guitar or bass, though the iPhone/Pod will roll off the low end (probably more noticeable for bass).

The JFET circuit is tiny enough to fit inside the 1/4" guitar plug.

These are the connectors. In addition, you'll need 1/8 watt resistors and an MPF102 JFET, available at any decent Radio Shack.

http://mouser.com/ProductDetail/Kobicon ... w6Vg%3d%3d

http://www.mouser.com/ProductDetail/Kob ... G2lQ%3d%3d

http://mouser.com/ProductDetail/Ampheno ... ObHwBxk%3d

iPhoneGuitarCable.PNG

http://joeorgren.com

[pwnified]

Awesome. You could use the "Upload attachment" and then "place inline" for the images.

[jorgren]

Note the new diagram above.

[JimStraynge]

Hi,
thanks Harmonicdog for the true awesome app MultiTrack. My question, is there a quick one-stop resource for input device solutions & reviews. Already this thread is awesome, but my brain drops more info that it takes in A one-stop info source would help me remember what to look for at the electronics store.
Thanks again 4 awesome MultiTrack. So easy to use, really cool!!

Edit: must tell it like it is: this thread already has massive awesome infos. I'll try to push off ADD and remember some of the stuff here

[Robertwalkiewicz]

I tried the a/v cable connection with my line 6 pod and it worked just fine. I used a 1/4 to 1/8 adapter and plugged that in to the headphone output on my pod, and plugged a 1/8 to a/v adapter to that. finally I ran the mini a/v cable to that. I just used the red cable on the mini a/v cable and plugged it into the 1/8 to a/v adapter and the itouch recogized it as an input. Ill post some pictures below.

[Robertwalkiewicz]

I mis-typed the names of the adapters above but here are the pics. you can find these at radioshack.

[rockula]

I'm not sure if it's due to poor English, or the inability to properly detail the above configs (no offense... i'm just frustrated!). But I am LOST. I don't get it at all. I have this exact same set up as you described, and it doesn't work. In fact, one of my A/V cables when plugged into the iPod, says that there is no mic attached! But this other cable I have DOES work. Still, nothing that I do gets my guitar sig into the iPod. Period.

I'm not sure what the deal is here, but I must say that dealing with getting a guitar signal into the Ipod Touch 3rd Gen 64g is much more frustrating and complicated then it needs to be. I don't want to build a custom cable, even though I could. I just want to plug into it and record guitar tracks along with the drums I've created in Beatmaker, or DopplerPad, etc. I don't understand why it's so difficult? And I'm certainly not going to buy a $250 breakout box to do so either.

So what is the deal w/ the iPod Touches being so difficult to get signal to it??

Thanks!
jason

[rockula]

I tried the a/v cable connection with my line 6 pod and it worked just fine. I used a 1/4 to 1/8 adapter and plugged that in to the headphone output on my pod, and plugged a 1/8 to a/v adapter to that.

ok.. what does "that" mean?

finally I ran the mini a/v cable to that.

Again??? "to that", being what?

I just used the red cable on the mini a/v cable and plugged it into the 1/8 to a/v adapter and the itouch recogized it as an input. Ill post some pictures below.

I have a 1/8" mini female, with a 1/4" male end, plugged into the headphone out of my ipod. Then I have a 1/8" male/x2 RCA female adapter... where the 1/8" male is plugged into the 1/8" female that goes to the headphone jack of the Pod.

Then I have an A/V cable... with three male ends... one yellow, one white, and one Red. I took the red male and plugged it into my adapter, leaving me with a yellow male and white male doing nothing, and one open white female on the adapter open.

Then I took the end of that A/V cable, which has three rings on it, and plugged it into my ipod. Says, "No microphone detected". But if I plug in this A/V adapter that I bought, with the same three ringed male ends into it, then plug the A/V cable male end into the female end of that adapter I bought, it at least doesn't say "no mic connected". However, no signal gets to the ipod still. Plus, how are you supposed to monitor what you're sending to the iPod???

I did manage to figure out a way that works, but you have to have the POD turned down pretty low making it hard to hear. And that was 1/4" to 1/8" out of the L Output, with a 1/4" to RCA adapt, with the A/V cable R and W connected to that, IN to the iPod input. That works, and sounds good, but the output level of the POD is the issue there. If there were a way control that level to the iPod without having to have it turned down in your ears, that would be fine. They sell these attenuators on eBay that are like a pass thru box with once single vol knob on it. That allows you send a cranked signal to the box from say a POD, but then control the output via the knob on the box. Something like that would probably work. Cuz then your headphone output would be loud, but the signal going to the iPod wouldn't have to be.

[jorgren]

Rockula,

You have to use a 3-ringed connector, like that found on the A/V cables. A regular 1/8" plug (stereo or mono) will definitely not work. ALso, not all A/V cables are alike. The ones that work, will have ground on the metallic ring 2nd from the plastic shell. If the A/V cable (as some do) has ground on the metal ring immediately adjacent to the plastic shell, it won't work. Next, plugging in the cable by itself will not do anything. The iPod expects to see a resistance in a certain range (in my experiments, 1 kohm to 10 kohm worked). That resistance, between the mic contact (the metallic ring next to the plastic shell) and ground (the next ring down) is how the iPod knows there's a mic connected.

Now, you could simply connect the guitar's pickup straight across mic & ground contacts; that's how the Paul Reed Smith / Bond GuitarBud works. But it doesn't work all that well. The iPod's mic input is low impedance, with a DC voltage. It will both kill your tone, and add crackle because of sparks inside your guitar's volume control.

Between my day job and my home life, I don't have time to build & sell the cable shown above (just my one kludgy instance of it). I can tell you that it sounds terrific though, and you or anybody else is welcome to use the design. If somebody manufactures a pretty version of it, I'll be the first customer.

[Agent36]

Really am enjoying this app its really amazing being 34, and having been recording since 4 tracks, to 2 inch, to pro tools, how far we have come in tech. i have a mikey, and it works well for acoustic, but i also have a em404 (external sound card), just sitting around and was thinking of trying that out. would suggest the above line six option, or would the 3 ring 1/8 cord work? would the phantom power be a problem? i'm just looking to have as many options as possible. i hace attached a pic of the back of the box. also i noticed propeller head released rebirth, i havent checked to see if they have an export feature, but any thoughts on getting some compatibility going with them? an iphone reason that could work in rewire with the your app, with the multi task update to the iphone 3gs/ 4 os, would be a dream road studio! sorry for the length and thanks in advance.

Filthy