Sunday | November 25, 2007

Mic Preamp Schematic for the iPod Touch

Many of our friends at the ipod Touch-fans forum did ask if I will provide the details of the circuit so that they can build it by themself. Well, here it is:


A little description:
- 13, 26 and 29 are the pin indices of the Dock Connector.
- The Resistor above the mic could be around 5kOhm, depending on your mic (see the note below)
- The capacitors C1 and C2 should be above 1microPharad, any vale is ok.

The picture quality is not the best, as it was made in a fast way on my N770 using the amazing Xournal noteTaker.
Anyway, what is important, in case you plan to build everything inside the Dock Connector, you will need to make a PCB that is all-in-all less than 3.5x 8x 16mm, as the internal height of the Dock Connector is 3.5mm. Not to mention that the position of the PCB will be also restricted (centralized) by the pins inside the plug. A smart solution would be to leave the PCB out and to put the resistors directly onto the legs of the IC. I will post a photo soon showing what I mean.

Dock Connector Pinout: ipodlinuxTeam

Believers who want to support the Project may click on the "Donate" button at touchmods.net. Thnx.
IMPORTANT!!
When using the tiny mic from the other posts, the Resistor above the mic should be 6,8kOhm. Simply, the best choise is when the voltage at the top of the mic is close to 1.65V, given, that Ucc=3.3V. Then there is no voltage on C1, ie. no transient clicks when you plug it in.


Posted by mrn at 18:19:11 | Permanent Link | Comments (9) |
Comments
1 - Awesome! Thanks for the design, I'll try it out !!! (Comment this)

Written by: Anonymous at 2007/11/25 - 20:07:41
2 - You ROCK!!!! :-D (Comment this)

Written by: cris01 at 2007/11/26 - 15:40:47
3 - For more details on the DEvice list,
and ordering numbers, pls go to post from Dec.5 or 6 , post nr. 25! mrn (Comment this)

Written by: Anonymous at 2007/12/08 - 19:06:41
4 - www.Conrad.de or www Conrad.at:

1 ST x 302007 MIKROFONKAPSEL
1 ST x 147567 TLC 272 CP
1 ST x 402427 SMD WIDERSTAND 100R 1206
1 ST x 402648 SMD WIDERSTAND 6K8 1206
3 ST x 402680 SMD WIDERSTAND 15k 1206 (Comment this)

Written by: mrn at 2007/12/14 - 23:26:30
5 - great, but how about a stereo mic? (Comment this)

Written by: Anonymous at 2007/12/21 - 20:14:04
6 - umm how do u make it (Comment this)

Written by: Anonymous at 2008/01/06 - 20:52:02
7 - ftp://www.correctv.com:@ftp-dom.earthlink.net/Mic%20Preamp.pdf (Comment this)

Written by: Anonymous at 2008/03/26 - 16:46:40
8 - Sorry here is the correct url for the schematic for the Mic Preamp

http://www.correctv.com/Mic%20Preamp.pdf (Comment this)

Written by: Anonymous at 2008/03/26 - 16:48:45 in reply to: 7
9 - There is a book with 200 pages,each page shows a picture of a bird and a story about that bird.You then turn a dial to the page number, press a button and the sound of that bird is heard.
I would like to do this with songs, Can you help me ?
beach_bum_68@msn.com (Comment this)

Written by: Anonymous at 2008/04/29 - 02:28:03
Write a comment