1. INTRODUCTION
In purchasing the new SM PR4, you have acquired a multi-channel pre-amplifier of high class
that meets many of the demands of the home/pro studio.
The market size for digital audio interfaces and computer based digital editing has increased in a
massive way. With systems available at very low prices, more and more users are utilizing this
technology. One of the main problems with many of these systems is the input stage only
consisting of unbalanced line inputs or very low (or no mic pre) gain structure for the balanced
input stage and the unavailability of Phantom power.
The PR4 comes to the rescue with 4 channels of balanced input, with a full range of gain control
from -20dB to +40dB and Phantom power for every channel. This half rack unit can now solve
many of the connectivity issues which are raised in a large range of situations, whether in the
Studio, home, club installation or other live sound applications.
2. THE DESIGN CONCEPT
2.1 High quality components and design
The philosophy behind SM Pro Audio products guarantees a no-compromise circuit design and
employs the best choice of components. The operational amplifiers NJM4558D which are used in
the SM PR4, are exceptional. They boast extreme linearity and very low distortion characteristics.
2.2 Inputs and outputs
All inputs and controls are secured firmly to the exterior chassis housing. This ensures robust
quality and confidence in performance under all conditions.
