Shopping Made Simple: Digital Recorders Page 3
Once you've decided on a recording format, it'll be time to choose a specific recorder. Here are some key features you should consider:
- Inputs and outputs. You can expect almost any digital audio recorder to have at least stereo pairs of analog input and output jacks, and typically there will also be inputs and outputs for direct digital connections. These come in two flavors: coaxial (electrical) and Toslink optical (sometimes referred to as "fiber optic"). One performs as well as the other. Just make sure the connections on the recorder match those on the components you plan to hook it up to.
- Recording-level indicators. When you're recording from an analog source, you'll need to adjust the level of the input signal to prevent overload on musical peaks. Look for peak-reading fluo res cent or LED level indicators with rea son ably fine gradations (no more than a decibel or two per increment) around the 0-dB red-line mark. If a deck doesn't have level indicators, it usually means there's an automatic level control (ALC) in the circuit. That makes things easy, but it also diminishes the recorded dynamic range. If you want the best sound quality, ALCs are best avoided.
- Sampling-rate conversion. CD and MD both use a sampling rate of 44.1 kHz. However, some other digital formats (digital audio tape, or DAT, for example) use different sampling rates. To make direct digital copies from such sources, a CD or MD recorder must convert the input signal's sampling rate to 44.1 kHz. Many recorders now have circuits that perform such conversions automatically. But you should check wheth er this seldom-used processing is kept out of the circuit when the incoming signal's sampling rate is already 44.1 kHz, to prevent any distortion the converter might introduce.
- CD synchro. This handy function starts recording automatically when you hit play on the CD player you're copying from.
- Dual trays. Many CD recorders now have dual disc trays to ease dubbing from CD to CD-R and to serve as a basic two-disc CD changer. Some can record from both trays. In most, however, one side is for playback only. Some MiniDisc recorders also include a CD player (or even changer).
- High-speed dubbing. Dual-tray recorders normally allow you to copy from one side to the other at faster than normal playback speed. Since the dubbing is done digitally, there's no penalty in sound quality. So all else being equal, the faster a dual-tray CD or MD recorder can copy, the better.
- A/D and D/A converters. Digital recorders include analog-to-digital (A/D) converters for making analog input signals into digital signals for record ing and digital-to-analog (D/A) converters for reconstructing analog output signals from recorded digital data. CD and MD are strictly 16-bit formats, and although many players and recorders use 20- or 24-bit converters, CDs and MDs can store only 16 bits of that range. Thus, while a 24-bit converter might work exceptionally well over the 16-bit portion of its range that a recorder or player actually puts to use, it won't give you a 24-bit CD or MD. Hard-disk recorders typically are designed for CD-level performance at best, so the same caveat applies.