Sony DVP-FX700 7-Inch Portable DVD Player
boostaroo does fix volume problem
as noted in other reviews, maximum volume is not loud enough when using this player on an airplane with inexpensive noise-cancelling headphones.  Based on a prior review and recommendation, I bought the Boostaroo amplifier from cyberguys.com for about $30 including shipping.  While I haven't used the amplifier in the air yet, it clearly does amplify volume with no discernable loss of sound quality.  This product makes a major disappointment  in the sony dvd player disappear.  <br />Thank you &quot;electronics fan&quot; for the tip.