DN100 is built to handle the rigours of life on the road, a thick aluminium extrusion protects the electronics, and in turn is covered by a tough silicone rubber sleeve. Exhaustive listening tests using a wide variety of active and passive bass guitars, electro-acoustic guitars and electronic musical instruments were carried out to select the components for DN100 to achieve the best musical sound. Not only was the choice of the audio transformer particularly important in achieving this goal, but the impedances of the surrounding components were also highly critical in getting the best possible performance out of the audio transformer. The line-driving characteristics of the transformer output were carefully optimised to provide the best frequency and phase responses for short and long cables and widely differing line and termination impedances. Care was taken in the design of the DN100 to avoid audio transformer core saturation and a fixed high pass filter has been included in the signal path to roll off frequencies below those that are musically important. The lowest note on a 5- or 6-string bass guitar is B0 with a frequency of 30.87 Hz, and the lowest note on an 88-key piano keyboard is A0 with a frequency of 27.50 Hz. DN100 still maintains a frequency response of i0.5 dB at these lowest musical notes. As well as the transformer in the signal path, DN100 also has a transformer to isolate the power rails to the input circuit from the phantom power supply sourced from the output XLR connector. When used in conjunction with the Earth Lift switch, this full galvanic isolation of input and output interfaces ensures that any risk of earth loops is avoided when taking a direct feed from stage backline equipment.
A custom instrumentation-grade input circuit was designed for the DN100 using advanced analogue design techniques to create the very high input impedance required by passive guitar and bass pickups, whilst keeping the actual component values low to minimise noise. This innovative approach to circuit design produces a very low noise floor, which combined with the high clipping point creates an unrivalled dynamic range in a +48 V phantom powered DI Box. DN100 features one parallel-connected XLR and two 14" TRS inputs, one which may also be used a link output for connection to a guitar or bass amplifier. When connecting to the XLR input only, the input impedance is 20 k Ohm, ideal for line level equipment and offering even lower noise performance. This input impedance is far too low for guitar and bass pickups and is removed from the circuit when a jack plug is inserted into a 14" TRS input, resulting in a nominal 1 M Ohm input impedance, ideal for passive electric pickups.
DN100 features illuminated Pad and Earth Lift switches, which along with the +48V phantom power indicator LED, provide 'at a glance' status display, even at wide distances and viewing angles.
The Earth Lift switch separates the input and output grounds, useful in eliminating earth loops between equipment on different mains electricity supplies.
DN100 is fitted with a locating slot for a Kensington lock for added security.