The purpose of a four-track recorder is to create complex arrangements from multiple sources. Tascam's DP-004 is one such product, capable of recording directly from two sources at a time. The DP-004 records to an SD (secure digital) card using two 1/4-inch jacks, the kind normally associated with DJ headphones. SD and SDHC (high capacity) cards are supported in its memory card slot, allowing up to 32 gigabytes (32GB) of memory.
The SD Association claims that SD memory cards "are used in some 400 products across dozens of product categories and in more than 8,000 models." Basically they're everywhere -- in our cell phones, our cameras and even our TVs. Only 24mm wide and weighing less than 2 grams, the SD card has entered every facet of our electronic life. SD will likely be with us for some time, due to its extreme portability and its ability to hold plenty of songs, videos and pictures.
The DP-004 records in a common file format known as “WAV.” This format offers some of the highest quality audio around, but to do so, it requires some rather large files. Using an equally large SD card can alleviate some of the space constraints you could encounter, especially during long recording sessions. About 100 minutes of recorded audio translates to about 1GB of data, meaning you could get 200 minutes of music out of the included 2GB SD card. A larger card will allow you to record a lot more music, but it also means you could lose a lot of data if you damage or lose the card. So weigh the benefits and risks carefully before purchasing large cards. Unless you’re recording for days at a time, a very large (16GB or 32GB) card may be unnecessary.
There are dozens of companies producing SD cards these days, making it difficult to know which to pick. For the audio professional — and even the hobbyist — the faster and larger, the better. Anyone looking for a comparatively high-end card should take a look at the card offerings of Sandisk, Lexar and Hoodman. All present high speeds, low failure rates and generous customer support. Sandisk’s Extreme Pro line currently offers some of the fastest speeds around; Hoodman’s RAW Steel makes claims of rugged durability; and Lexar provides quick turnarounds on warranty replacements. You must determine the right card for your needs, but these will get you headed in the right direction.