The Bruel & Kjaer 2706 Power Amplifier 10 Hz - 20 kHz, 75 VA has been designed to drive small vibration exciters, particularly the Bruel & Kjaer Vibration Exciter Type 4809. It can also be used to drive the Mini-Shaker Type 4810 to full rating. For this application, the maximum output current should be limited to 1.8 A. The power amplifier has a flat frequency response from 10 Hz to 20 kHz ( ± 0.5 dB). The power output capability is 75 VA into a 3 Ω exciter or resistive load and the maximum voltage gain is 40 dB. This enables the power amplifier to be used in acoustical measurement set-ups, even when third-octave narrow band noise is employed. The use of a transformerless power output stage and high negative feedback results in very low harmonic distortion. A balanced preamplifier and rugged solid-state design results in a stable instrument which can tolerate temperature fluctuations and supply line variations. CE-mark compliance with EMC directive and low voltage directive.