[nickbatz]

http://www.markertek.com/Cables/Audi...NE-MIC-1.xhtml

The goal is to plug in a tiny electret condenser mic - a cheap iPhone headset with its headphones snipped off would be fine if not ideal - and still have the headphone output. And not pay $30.

This is the wiring scheme:

Pin t tip - left audio/headphone L +
Pin 2 ring - right audio/headphone R +
Pin 3 ring common ground for mic and headphones
Pin 4 sleeve - mic +

I've read about requiring a 1KΩ resistor between the iPhone side of the mic wire and ground so that the iPhone detects that an external mic is connected. Is that all you need?

The straight cable I wired has issues, and I just found some cheap adapters that don't work (headphones low level, distorted, no bass; mic low level and crappy).

TIA

[Mike Rivers[_2_]]

On 3/14/2013 5:28 PM, nickbatz wrote:

The goal is to plug in a tiny electret condenser mic - a cheap iPhone
headset with its headphones snipped off would be fine if not ideal -
and still have the headphone output. And not pay $30.

When I was experimenting with the audio I/O capabilities of my Samsung
Galaxy 10.1 tablet, I got this cable from an Amazon supplier:

http://www.amazon.com/gp/product/B00...?ie=UTF8&psc=1

It was under $3. It's actually sold as a cable for connecting a digital
camera to a TV set, but it has RCA plugs wired to the appropriate
segments of the TRRS plug to get a mono input and left and right
outputs. It's a little audio-odd in that the red plug is the input and
white and yellow are the left and right outputs. Perhaps cameras are
wired differently so that the yellow plug, which conventionally carries
video in this sort of cable, has video rather than audio on it. Or maybe
now. Anyway, you could cobble up what you want from this cable.

I've read about requiring a 1KΩ resistor between the iPhone side of
the mic wire and ground so that the iPhone detects that an external
mic is connected. Is that all you need?

I'd never heard that, but I tried it with my tablet. Perhaps the
external mic is detected when it sees current being drawn from the
plug-in power source. I have an IK Multimedia iRig Mic which works fine
with it - plugging it in disconnects the internal mic. Same with the
cable. I tried putting a 1k resistor across the input connector on the
cable and I couldn't determine from the surface that it did anything.
Curiously, when I connected a 100 ohm resistor across the input, a media
player app popped up.

All of these portable devices work differently. I'm sure that there's
some processing, both bandwidth filtering and compression or limiting
going on when using the internal mic. I don't know how that changes when
you connect an external mic, but I know it's different. For example, I
can clearly measure compression when using the internal mic with the
Audio Control SPL Meter app, and that isn't present with the external
mic. That app has a pair of Internal/External mic buttons but it doesn't
switch automatically. However without an external mic connected and
switching the app to External mic, the meter still works (on the
internal mic) but the response is different than when it's switched to
Internal. Of course none of this is documented.

The straight cable I wired has issues, and I just found some cheap
adapters that don't work (headphones low level, distorted, no bass;
mic low level and crappy).

Are those your "issues?" I've never tried connecting headphones to the
outputs of my cable, but I use it as line outputs (into a mixer) and it
sounds fine. Try that Parts Express $3 cable. Buy two, one to keep for
study, the other to adapt to your mic and headphones.

While I don't have one, I'll put in a word for the IK Multimedia iRig
P http://www.ikmultimedia.com/products/irigpre/

It has an XLR input, a standard stereo headphone output, and you can put
a 9v battery in it and have it provide real 48v phantom power for a real
condenser mic. It's about $40, but if it works as well as the iRig Mic
(I used it for interviews at the NAMM show) it's worth it, and more
useful than the $30 cable you identified.


--
For a good time, call http://mikeriversaudio.wordpress.com

[Sean Conolly]

"Mike Rivers" wrote in message
...
On 3/14/2013 5:28 PM, nickbatz wrote:


While I don't have one, I'll put in a word for the IK Multimedia iRig P
http://www.ikmultimedia.com/products/irigpre/

It has an XLR input, a standard stereo headphone output, and you can put a
9v battery in it and have it provide real 48v phantom power for a real
condenser mic. It's about $40, but if it works as well as the iRig Mic (I
used it for interviews at the NAMM show) it's worth it, and more useful
than the $30 cable you identified.

Thanks for that link! I'm spending more time on conference calls from home,
and this could help out.

Sean

[nickbatz]

Thanks Mike, you the guy.

I have the Tascam iXZ for "real" recording, and it's great (has battery for phantom power, works very well). This doesn't have to sound good, just work. $3 is appropriate. Will get a couple of those cables. Thanks.

[nickbatz]

From what I can find online, the pinout of the cable you have - a generic AV cable - is:

Tip - Left Audio
Ring - Video
Ring - Ground
Sleeve - Right Audio

But the iOS one is wired:

Pin t tip - left audio/headphone L +
Pin 2 ring - right audio/headphone R +
Pin 3 ring common ground for mic and headphones
Pin 4 sleeve - mic +

So if my brain is working right, that would explain why the yellow RCA plug is the right audio out.

[Mike Rivers[_2_]]

On 3/16/2013 9:15 PM, nickbatz wrote:
From what I can find online, the pinout of the cable you have - a generic AV cable - is:

Tip - Left Audio
Ring - Video
Ring - Ground
Sleeve - Right Audio

But the iOS one is wired:

Pin t tip - left audio/headphone L +
Pin 2 ring - right audio/headphone R +
Pin 3 ring common ground for mic and headphones
Pin 4 sleeve - mic +

So if my brain is working right, that would explain why the yellow RCA plug is the right audio out.

Correct. I was going to wire my own, but I could find only one source
for a plug and that cost more than the assembled cable. Jacks are even
harder to find, so I haven't looked at the actual position of the
contacts. In thinking about that business of opening a player when
putting a 100 ohm resistor across the "mic" input, perhaps it thinks
I've plugged in a headset and want to listen to some music.




--
For a good time, call http://mikeriversaudio.wordpress.com

[John Williamson]

On 17/03/2013 13:03, Mike Rivers wrote:
On 3/16/2013 9:15 PM, nickbatz wrote:
From what I can find online, the pinout of the cable you have - a
generic AV cable - is:

Tip - Left Audio
Ring - Video
Ring - Ground
Sleeve - Right Audio

But the iOS one is wired:

Pin t tip - left audio/headphone L +
Pin 2 ring - right audio/headphone R +
Pin 3 ring common ground for mic and headphones
Pin 4 sleeve - mic +

So if my brain is working right, that would explain why the yellow RCA
plug is the right audio out.

Correct. I was going to wire my own, but I could find only one source
for a plug and that cost more than the assembled cable. Jacks are even
harder to find, so I haven't looked at the actual position of the
contacts. In thinking about that business of opening a player when
putting a 100 ohm resistor across the "mic" input, perhaps it thinks
I've plugged in a headset and want to listen to some music.


For earphone compatibility, I'd expect T= Left audio out (White phono
centre pin), R = Right audio out (Red phono centre pin) as normal, then
either R = Audio in or common Ground (Yellow centre pin or sleeve), and
S= common ground or audio in (Yellow centre pin or sleeve). I've seen
both layouts on combined video and audio feeds, according to who made
the unit.

So, you may find that the centre connection on the yellow phono is
common ground for all signals, and the sleeve on all the phono
connectors is audio in, or vice versa.
--
Tciao for Now!

John.

[nickbatz]

Okay, so that means I need to check the wiring of 3&4 before ordering six of them for $17.

Thanks.