Recording

From wikiPodLinux

Using podzilla you can record audio at sample rates of 8, 32, 44.1, 88.2, and 96kHz. The bit depth of these recordings is 16-bit. There are two ways to record audio: with the headphone jack and with the dock. Each of these options may be accessed under Extras->Recordings. In addition to recording, podzilla also allows you to play back your recordings; however, be aware it is a bit buggy.

Using the latest nightlies, 3G, 4G, Photo, and Color iPods are able to use Mic recording and only 3G iPods are able to use Line In recording. 1G, 2G, and iPod Minis are not able to record! Recording on the Nano and the Fifth Generation iPods is also not currently supported.

Recordings are saved in the WAV file format in the Recordings directory. If you do not have this directory on your iPod, you will need to make it in order to record. If the folder exists in Windows but the iPod doesn't recognize it, you may have to create a link in your Windows folder, using:

mkdir /hp/recordings

in a start file.

Recordings are saved in the same way the Apple Firmware saves them, so they should be imported by iTunes. iTunes will delete them once they've been imported.

To record, choose the sample rate, then select either Mic Record or Line In Record. Pressing the center button once will activate recording and pressing the center button again will stop recording. When you are done recording, you can press the menu button to get out of the recording screen.

To play back your recordings you can select Playback and then navigate to the file you want to play back. File names are in the format MMDDYYYY HHMMSS.


Mic Recording

Mic recording is mono and is recorded through the left channel of the headphone jack. If you are attempting to make a connector you will want to pick up a 1/8" stereo phono jack. Usually the center pin is the left channel and the ground is the largest metal connection on the jack.

The iPod has a built in preamp and supplies bias power (1.5V) through the headphone jack so a preamp and powered mic are not necessary. If you do choose to use a powered mic and/or a preamp make sure you do not overload the iPod!

Notes: Currently iTalk and other iPod recording devices are not supported by podzilla.

Stereo phonejack
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Stereo phonejack


Line In Recording

Line In recording is stereo and is recorded through the dock. Unlike the headphone jack, the dock does not provide a bias power or a preamp so if you choose to record through the dock, you need to make sure you have these. To record from the dock you will first need to make a dock connector. The pins necessary for recording are 2, 5, and 6 which are the ground, right, and left channels respectively. The dock layout and where to get dock connectors is located on the Dock_Connector page.

Notes: How to solder dock connector:

  1. Cut small lengths of wire and strip the ends of the wires.
  2. Tin wires.
  3. Get an index card and wet it, then place it over the pin you want to solder.
  4. Pull back the jacket of the wire and then place the wire on the dock connector.
  5. Hold soldering iron on top of wire close to solder and then wait for solder to melt and make the connection.
Dock Connector
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Dock Connector


Circuit diagram for home-made bias power circuit for stereo mic:

Bias Power Circuit
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Bias Power Circuit


Stereo Preamp kit: http://www.rainbowkits.com/kits/ebap-2p.html

Picture of home made powered stereo mic and preamp:

Homemade Stereo Microphone Parts
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Homemade Stereo Microphone Parts


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