<p>What I would look for in a digital recorder:</p>
<p>1) The ability to use external microphones in place of or in addition to any that may be provided, which could be achieved by providing two XLR inputs with phantom power, or by providing two mono or one stereo line level input. (Professional line level, not consumer-grade RCA jack inputs). Bonus points for balanced TRS inputs.</p>
<p>2) A USB2 or later interface to a computer that allows the unit to appear as a disk drive when connected. Bonus points if it can be used as a portable hard drive for non-audio computer files.</p>
<p>3) Ability to record to standard WAV files in CD format (44.1 kHz, 16 bit PCM stereo). Bonus points for higher sampling rates, larger sample sizes and the ability to work with more than two tracks at once.</p>
<p>4) Both battery and AC power options. Bonus points if the AC plug is on a cord and not molded into a “wall wart”.</p>
<p>5) Headphone out jack. Bonus points if it can drive a set of 600 Ohm monitor headphones to reasonable levels, at least when AC powered.</p>
<p>6) Recording level controlled by a physical dial or button, not implemented in software and buried several levels deep into a series of menu screens. If AGC (automatic gain control) is provided, it MUST be defeatable and should not have to be turned off every time the unit is powered up. Bonus points if there is a separate level control knob or button for each track so that I can adjust two at a time.</p>
<p>7) If it has built-in mics, then it should also have the ability to be mounted on a tall microphone stand. Bonus points for remote control capability that allows the user to set levels and control recording functions without having to stand on a ladder.</p>
<p>8) If the unit uses an LCD or similar display for any important functions, it must be readable in the dark but not so bright as to draw undue attention to itself.</p>
<p>9) Digital inputs and outputs in either S/PDIF or optical format.</p>
<p>10) Compatibility with a standard timestamp format (e.g. BWF) that allows files recorded on the portable unit to later be synchronized with professional studio equipment.</p>
<p>11) Uses removable, non-proprietary solid state storage media, e.g. SD cards. Bonus points if it can be inserted directly into a laptop or card reader and be read directly by the computer.</p>
<p>I have not found the perfect portable unit yet, but the Marantz PMD620, the Tascam DR-100 and the Zoom H4n are all worth consideration.</p>