Sound Techniques, a New Zealand company have designed, and are producing, a unit for upgrading Fostex's PD4 DAT monitoring. Their HPB-01 provides high quality headphone listening with comprehensive headphone switching enabling stereo / mono / left only / right only / M&S decoding, and difference monitoring. Using surface mount construction and high quality components it fits inside the PD-4 recorder in a blanked hole on the input channel. Power consumption from the internal rail is low and is fuse protected. The HPB-01 kit contains circuit board, selector knob, two interconnections and a self-adhesive decal to indicate switch positions. For more information and sales contact Will Blackham at Location Technical Facilities on 01895 813698, the sole UK distributors, or see Sound Techniques' web site - http://webnz.co.nz/soundtechniques/