Battery-operated af pre-amplifier - part 1

This preamplifier is intended for those audio enthusiasts who are interested in only the best. Its discrete design produces distortion figures that are measured in ten-thousandths of a per cent (the remainder of its specification looks very good, too!). Moreover, bearing in mind that in certain areas the mains supply voltage is not as pure as it should be, the preamplifier is powered by rechargeable NiMH batteries. In this first of a two part article, the preamplifier proper will be described. The second part, to be published next month, will deal with the specially designed battery charger.