Etree.org DAT Conversion FAQ v0.9
1. What do I need to transfer DAT to CD?
You'll need a DAT deck, an interconnect cable (coaxial, optical, or AES/EBU), a Computer (w/aproximately 3-4gb free hard drive space), a Digital Soundcard, Wav editing/recording software, and some time and patience.
2. What soundcards allow for bit for bit digital transfers?
There are many soundcards that allow for digital transfers. A few of the prefered cards are the Zefiro ZA2, Turtle Beach Fiji/Pinnacle, Event Gina, and the SONICPort/DATPort which are both USB devices. For a more extensive list of soundcards with reviews and specs, visit http://www.digitalexperience.com/cards.html
Note: The Sound Blaster Live series and Turtle Beach Montego II perform unecessary resampling of
data and are therefore not recommended for use in DAT > CD applications, as noted at http://www.sospubs.co.uk/sos/jul99/articles/pcmusician.htm.
3. Why can't I just use my regular soundcard?
Computers are very noisy machines, electrically. When I plug headphones into my SoundBlaster AWE64 Gold, one of their "high-end" cards, I can hear a noticeable hum in the background from all the electrical interference in the machine. If you were to convert an analog signal to digital inside a computer, you pick up all that noise and get a hissy copy.
4. What software should I use to record and edit?
There are many wav editors available for Windows OS's. Cool Edit, Sound Forge, Samplitude, and CDWav are the most common. CDWav does not allow for extensive editing, but is the BEST way to split a show into tracks. More information is available on thes products at (insert links url here)
5. What software should I use to create tracks in my wav files?
Tracks can be created by using a wav editor. When creating tracks, one must make sure that the tracks are cut on correct sector boundries (multiples of 588 samples). CDWav cuts on correct sector boundries by default and therefore is the preferred program to use for tracking shows. CDWav is also the easiest application available for tracking shows. Cool Edit and Sound Forge DO NOT cut on correct sector boundries by default.
6. What are sector boundries? and why should I care about them?
In order to create a live DAO recording without any clicks or gaps between songs, you must make sure the audio in your wav file is a multiple of 2352 bytes (588 samples) long. Most audio editing programs will allow you to choose a block size for editing to ensure that when you split a large wav file into smaller wav files each small wav file will contain an integer number of blocks. If you choose your block size to be 2352, no padding will be done by your cd burning software, and the end of one track will flow seamlessly into the beginning of the next track without any silence or clicks (The correct way).
Note: A wav file contains a short header followed by the audio data. I have found that the length of the header is (almost always) 44 bytes. So, if you want to do a quick check of whether a wav file will be burned DAO without any padding, subtract 44 from the size of the
wav file and divide by 2352. This number, which represents the number of blocks, should be an integer (contain a fraction of 0.0000, i.e, 745673.0000 blocks).
CDWav cuts on correct sector boundries by default, therefore is the preferred method for tracking a show.
7. How do I determine which tracks will fit on a 74 minute disk?
Generally, try to follow a few simple rules when splitting up disks. Keep complete sets on the same disk whenever possible, split the disks so that the continuity of the show is not impaired (DO NOT REORDER THE SONGS). Don't split a segue between discs. Try to use a 74 minute disk, but when a 80 minute disk is needed, include that in the info file, and if possible provide for an alternate tracking solution for those who wish to use only 74 minute disks.
8. Should I fade in and out of each disc?
Fading in and out of each disc is generally considered bad practice in the trading
community. The only areas where fades should be used, and don't have to be, are at the
beginning and the end of a show/set.
I think all traders will agree that the only parts of a show that should ever be faded would
be crowd noise, never music. Remember, we will most likely be transfering this music from CDR to DVD in a few years, and we'd like to be able to reassemble a complete show without fades screwing up the continuity of the show.
9. What is sampling rate (44.1KHz, 48KHz, etc)?
The sampling rate is the number of samples a digital recording has per second. There are different ones out there - Redbook Audio standard for CD's is 44.1KHz, DAT's can be 32, 44.1, or 48KHz, and DVD-Audio, a new standard, can be all the way up to 96KHz.
The benefits of higher rates is greater resolution of sound - technically, the high end comes out a bit better, and the sound is more nuanced. Keep in mind that in order to burn a CDR the sample rate of the wav files must be 44.1KHz.
10. How do I put a 48kHz DAT onto CDR?
The Zefiro ZA2 has an onboard sample rate converter that will allow you downsample on the fly for CDR preperation. If you do not have a ZA2, you will have to use a form of software resampling. The easiest way to this is to record your 48KHz DAT into your computer using Sek'd's Samplitude software. Samplitude allows you to resample from 48KHz > 44.1Khz at the time of recording, so that your resulting wav file is already 44.1KHz when it is created.
If you cannot use either of the two "on-the-fly" methods above, then you can use a wav editor to do the resampling for you. This process would require you to record the wav at 48KHz onto your hard drive, then use Cool Edit, Sound Forge, or another wav editor to resample the wav data from 48KHz > 44.1KHz. Instructions on how to do this should be available with your wav editting software.
11. What do I do if the volume is low on the DAT and I want to raise the levels before I put the show onto CDR?
The amplitude of a wav file can be raised using software and a function called Normalizing. Normalizing can be done in any major wav editor. Normalization is the process of raising all levels in a wav file equally with respect to 0dB. If you feel the need to normalize, you should normalize to the PEAK value and NOT RMS value. You should also normalize the entire show at one time or you will screw up the levels from track to track. Normalization is only necessary when the peak amplitude levels of a show are very low.
12. How much hard drive space do I need to transfer a show?
An average 2.5 - 3 hour show is approximately 1.2gb - 2gb in size. It is in good practice to have at least double that amount of drive space per show, because as you track it you will want to save individual tracks for burning.
13. How do I remove tape hiss from my recordings?
The above mentioned wav editors have noise/hiss reduction tools which can be used. Noise/Hiss reduction is a process which should be left to the experts. Consumer audio applications such as Cool Edit and Sound Forge do not do a particularly good job handling hiss reduction especially. Basically, DON'T USE NOISE REDUCTION!!! or at least on shows that you wish to circulate.
14. What kind of digital connections are there?
There are three major kinds of digital connections. The first two are part of the Sony/Phillips Digital Interface Format, of S/PDIF. They are the two
most common connections you'll find.
Coaxial - this is the most common. Electrical signal with a charge being a 1 and the absence of a charge being a 0. A coaxial connector looks like an RCA jack, except it's usually not color-coded and there is only one jack.
Optical - Popular with Sony. It uses a red LED and fiber optics to send a kind of morse-code signal to transmit the data. The most common connector is a Toslink socket, which is square-ish. You can also tell an optical output because it's emitting red light.
AES/EBU - uses XLR connectors and is borderline compatible with S/PDIF. The nice thing about this one is that it does not transmit SCMS, and is especially popular among "pro" audio engineers and tapers. AES/EBU connectors are Big XLR connectors, and there is only one per direction (where as analog XLR's usually come in pairs)
15. Can I extract audio from the DAT backup drive on my computer?
This can be done on some older SGI tape drives. More information is available here: http://www.ncf.ca/~aa571/dat2wav.htm
16. If I have a DAT tape, but no way to get it onto CD, are there people who are willing to do the conversion for me?
Yes, there are plenty of people around that are willing to help out with DAT > CD transfers. We'll have a list of people here soon.